Trying to resurrect my dad's Evo Dyna. He passed about 15 years ago and the bike wasn't rode for about 4 years before that. Now my brother's son wants to start out on his granddad's bike. So it's important to get it going. Carb issues are beating me and are the last thing to get right before it goes to my nephew.
Original carb was off the bike and gone. No idea what dad did with it and couldn't find it. Had a few other cores around so tried to make one up. It's a original CV were messing with.
Had a damaged body from a early Twin Cam era Dyna and took all the needles and jets from that. Carb was never opened before so it's all a matched set of pieces. Used them and a good kit in a well cleaned other carb body and put one together from the collection of parts.
Some of the details might not matter but I don't know for sure what's importnat and what isn't so will probably list more than I need to.
Bike starts good hot or cold.
For hot idle to be good right at 1000 cold idle is just a tick slow at maybe 1200.
Idles really good. Nice and smooth and no raggedy vibration.
Cracking the throttle at an idel sounds just fine.
Parking lot driving manners is good. No issues at all under very light load like that.
Under heavier load like pulling hard away from a stop sign or climbing a highway onramp or just cruising on the highway it runs fine. Have put a couple hundred miles on it now running 60-80 and it's a good riding bike on the highway.
Problem is in between. Like medium load and RPMS of maybe 1500 to 3000 and loads like you'd do riding in town. Both accel and decel it coughs and spits. It's not like you think the engine is going to stop running. But you can feel it chug a little and it's a sound and feel you definitely notice. It's not right.
Also, idle mixture screw seems to have almost no impact. Take it in all the way and you just barely hear the slightest difference. Have tried running the bike with the screw almost all the way in and about almost two turns out and it makes no difference to that middle range popping and coughing that's going on.
Did a I think good job cleaning it out. First 100 miles it had a dose of SeeFoam in the fuel too so that should have helped even more.
It's got new plugs and wires. I don't think it's an ignition problem but I'm willing to consider any ideas someone might make. Have had the carb off half dozen times now tweaking and cleaning and checking and nothing changes that bad running problem in the cruise range that you'd do around town.
Gas mileage on the test runs so far is about 38. So not great for a stock Evo and it should do better but cruising on the highway it's really well behaved and feels great. Oh yeah, stock exhaust too.
Got everything else done, new tires, bearings, seals, tank flushed, etc etc etc that should be done since it sat so long. Looking forward to my nephew getting his granddad's bike if could just get the carb issue better. Any ideas please.
Hello Chip.
So in my experience, one of the weaknesses of the CV carb is it's susceptibility to plugging up the transfer ports. This causes bad performance between idle, and full power. The transfer ports are those array of holes at the bottom of the bore, just in front of the throttle plate. There are usually about 4 of them, sometimes 5. Backfiring and such tends to plug them up with carbon. After that, you lose that off idle to main jet fuel metering.
Running Seafoam through the carb will do nothing to clean these out, if they are plugged. You need to take the carb completely apart, and using Brake Kleaner(tm) or some other such solvent, blast the crap out of the carb body. Then, you need to use some fine round files, such as those used to clean oxy-acetylend torches with, to poke through the transfer ports to make sure they are not blocked. Using the throttle to slightly crack open and position the place just past the transfer ports, blast the :turd: out of them with the Brake Kleaner(tm) to wash them clear.
Put all back together, and give it a go. One thing many of use have is a small ultrasonic cleaner from places like Harbor Freight, which filled with Pine Sol(tm), does a great job of cleaning things like carburetors.
If all else, you can find a reasonably good CV carb on ebay, a cheap knock off Chinese made version that from what I've found, works pretty damn good. Not my first choice, but if money is a concern, a great second choice.
Good luck,
JW
one starts at the beginning
1/ motor size and cam used and pistons
2/ pipes and air cleaner
3/ what carb being used
4/ go back to the drawing board as the the original jets etc
5/ a tear down and rebuild, neddle in right slot ? vacumme slide rubber check,vacumme line hole check,
6/ inlet manifold and gaskets check
7/linkages used, and adjusted to specs
8/ air cleaner fitment
9/ fuel delivery , tank ? petcock? delivery line ,
10/ vos module check if it has one
11/ timing , plugs leads coil etc
12/ basic tunning , mixture out one and a half turns , throttle stop screw adjustment around 1000 revs
heres a few tips i use to eliminate issues,once you have it going , the bike manual helps, in needle slot ? idle jet,and main jet etc ,
hope this helps a bit ,its a back to basics method that ive never had a problem with , cheers Barny
If I understand correctly, the jets and such are from an early era twin-cam. If so, I suspect the low speed jet (at least) is too large. 38 mpg seems to suggest the same. chugging of the engine and failure to respond to changes to the idle mixture screw also suggest the same.
Well tuned evo CV's do fine with a 42 slow speed jet. You might start there and post some feedback.
Check for air leak at intake seals.
This has all been helpful. The motor is a completely stock Evo. The jets in it now are 180 and 45. The intake seals and carb seal are all new and show no signs of leaking when you spray at them. Plugs and wires are new along with a lot of other work all over the old bike. It's just this middle power range surging and coughing and spitting.
The message above about a more thorough cleaning being maybe a problem sounded like a good description of the behavior of this bike. Thanks to everyone and especially thanks to that one. I will work on it again and pay even closer attention there. I even have a little sound cleaner like you mentioned and just never thought about it for the carb parts.
I also just looked at the rest of my spare parts and found a 40 and a 42 and a 170 and a 175 jet. What would be a better pair for this bike? Just a little Dyna with stock motor and stock pipes. Even back in the day I never messed with bike carbs enough to learn what worked best. So thanks again.
Just read all the stuff above once more time. The voes switch and petcock are both new. Old ones hadn't survived setting for so long time. Vacume line and fuel line are all new too.
For a stock Evo, use the 170 main, and the 42 pilot jet.
All good advise above.
As JW113 suggested above, try the torch tip cleaners or a piece of wire from a bread wrapper, strip the plastic and run it through the holes.
Any dirt that a carb picks up is from the outside, so use air or carb cleaner blown from the inside of the carb out.
Blowing air or carb cleaner from outside/in could lodge any dirt or crud tighter into the orifices.
Just my .02
Good luck, will be waiting your feed back.
Thanks again to everybody. Have found on line pics showing exactly the places your telling me need cleaned. Now know what I'm looking for. It will be one evening this week before I get to be back where the bike is but will brag or cry about how good it went as soon as I know.
I remember on coughing spitting evo and shovel motors I Used to drill out the mid range jet that was hidden under a soft plug on the old CV carbs. I bet I did 50 of them.
I would carefully drill through the plug, use a #drill to open up the hidden jet then cover the drilled hole with epoxy. Worked wonders.
~John
Quote from: jmorton10 on July 31, 2019, 08:30:27 AM
I remember on coughing spitting evo and shovel motors I Used to drill out the mid range jet that was hidden under a soft plug on the old CV carbs. I bet I did 50 of them.
I would carefully drill through the plug, use a #drill to open up the hidden jet then cover the drilled hole with epoxy. Worked wonders.
~John
Now you've gone farther than what I know. I have removed plugs to get at the mixture screw many times but don't know anything about a jet other than the main and the slow jets that can be unscrewed and replaced.
I will second JW113's response 100%. Anything that has ever had gas run through it and then put into long term storage will likely have varnish buildup and those tiny off-idle orifices being plugged will likely cause exactly the problem you describe because that is what is used most in that RPM range. Pine Sol in the ultrasonic cleaner should do the trick and not damage the carburetor body. That is what I would be doing for sure.
Another question. Carb is apart again this morning. Has been soaking in the little ultrsonic cleaner and pinesol for a half hour. Rinsed it off and blew it all out and it definitely looks even better than it did after the prior time it'd been cleaned up. How do I know if the holes are actually clean all the way threw though?
The little single hole that goes to the mixture screw you can tell. It's open all the way through. The five in a group though how do you tell? I can take a bread wire and put it down each hole just s little bit. It's about the same on all of them but it goes only a little bit. I'm guessing the holes turn a corner there but I dont know. Can't see light threw to anyplace at the other end but if they turn a corner I wouldn't. So how do you know they got cleaned out?
Read this article:
https://cv-performance.com/harley-cv-carburetor-tuning-issues
Cover the mixture screw hole and the pilot jet (slow) jet hole and with both holes covered apply compressed air to the slow air jet (bottom left hole at the front of the carburetor). That will force the air through those tiny ports you are trying to clean. You have to cover the mixture and pilot jet holes or your compressed air will come out these instead. Or I guess you could cover any two and blow through the third. Google a diagram of the carburetor circuits and you will see. You can get a can of compressed air at an office store.
Thank you again for all the assistances and advice. Got back an hour and a half ago from riding the bike for a couple hours. It's better. It didn't get blown out exactly as described by the last person but it did get blown out a lot. It's better. It's not perfect but it's at least ride able.
The near constant midrange spitting and sputtering is gone. In hour and a half riding I heard slight decel pop twice and it spit very light in that mid range twice. Of that 90 minutes almost half was riding around town. So it would have shown up more if it was bad. It's still not completely right though.
The choke cable barely bumps up a fast idle and the mixture screw still doesn't actually change anything. Can run the mixture screw all the way in or way out and it never changes anything. The bike runs good though. Really well behaved low speed like parking lots and running around town it was ok. On the highway it doesn't miss a lick. Juts installed now are 42 and 170.
Can take it apart again and try blowing it out even more as described from the last person above. If it starts ok cold in the morning and proves it will stay running I'll know more about the choke. It was a warm afternoon when it didn't seem to do much earlier today. I wish the mixure screw actually did something but if the bike runs good and the mileage is ok I could live with that too. Could live with it until maybe doing a new carb over the winter or something.
Wish it was all good. But it is a lot better than it was and its ride able now.
If the idle mixture screw doesn't seem to do anything you need to lower the idle speed setting
then adjust mixture again.
You don't need to take it back off. Get a can of compressed stuff and blow back through the slow air jet. The mixture screw will be in place so it won't come out there and the slow jet will be submerged in gasoline so most of the air will go through those small ports. Actually those cans of "air" are actually compressed liquids. if you spray with the can upside down that will dispense liquid and that mat be even more effective. You could even try WD-40. If you have it running decent I would try several tanks of gas with extra detergent, like maybe Techron or similar and that will probably finish the cleaning If you still get an occasional carburetor "sneeze" then you can probably solve it by shimming the needle with tine washers and/or going up one size on the slow jet. Always tune the carburetor one step at a time.
Quote from: bump on August 04, 2019, 03:48:09 AM
If the idle mixture screw doesn't seem to do anything you need to lower the idle speed setting
then adjust mixture again.
When the idle mix screw does nothing it means the slow jet is too big.
In my dealings, a 42 pilot jet is quite small. Never have been able to use anything smaller than a 45.
Idle jet screw not having any effect often means the throttle plate is open past the transfer ports, and pulling fuel from them. Unclear why this would be the case for a stock bike, though. I realize that pulling the carb off is a pain, but I think if you did, and looked at the back side of the throttle plate, you might see an exposed transfer port or two.
What is your idle speed?
-JW
Get you an S&S e. Problem solved.
You might try this.
Put the 45 pilot jet back in.
Ride the bike until it's warm, then shut it off.
Turn the idle mixture jet in until it lightly touches the seat.
Back it out two turns.
Turn the idle speed adjust screw out until it is no longer touching the throttle lever.
Turn the idle speed adjust screw in until it just touches the throttle lever.
Turn the idle speed in one more turn.
Fire up the bike, using the throttle grip to keep it from stalling.
Adjust the idle speed screw to get an idle 900-1000 rpm.
Now see if turning the idle mixture jet in, then out, causes the rpms to increase and decrease. The correct adjustment is to turn in until the rpms start to drop, then counting # of turns, back it out until rpms come back up then start to drop again. Correct adjustment is 1/2 way between those two points.
-JW
Will look at all this again. And thanks once again. Even more detail to pay attention to. Fortunately it's got to the point where I can get the carburator off the bike in about 5 minutes!
Home from work early today. Took it back apart again and found something maybe. Haven't had a chance to put the carb back on the bike yet but it is put back together.
The butterfly was opened past a couple of the little holes that it should not have been. That's where the idle screw was holding it to have it idle at 1000 rpm. Idle screw now backed off. The throat is clean and polished as is the side of the butterfly. Changed from 42 to 45. Will see if that combination of things makes a diffeence.
Can't say if all the holes were completely clear before. They are now though. With better idea of where all the passages went and what to took for and do was covering different places and either blowing by mouth or with the compressor. Blowing by mouth I could hear and feel air coming through every where it should be.
Maybe later tonight will get the carb back on the bike and run it. If not it may be Thursday before there is a chance to try it.
Chip is now officially frustrated with this motorcycle. Did get look at it again tonight. Initially it fired just a little then it died and wouldn't run again. It would once in a while barely kick but wouldn't run. This was new.
Started from scratch chasing it like I would a new problem. Cam senser was melty. Soft and goop that had begun to run off of it. Actually hoped it had been in the process of dieing for awhile and might account for some of my other issues. Did not get that lucky.
Just beofre closing got to a local indie shop and got what I could. He had an Ultima Single Fire kit. The one with everything in the nose. Got it all changed and timed and the bike starts better than it ever did.
Rest of the problems not so much.
The carb is really very very clean now. Can blow through everything and air comes out everywhere. It starts and idles wonderful. It will idle all the way down to about 550 and still be smooth. Below that it'll die. I only kept it that low to see if I could ever adjust the mixture screw. Even at an idle setting that low still get no response from the mixture screw. There is no vac leak at any of the three seals on the intake. Triple checked that with WD40 and with starting fluid. No vac leak inside the voes switch either. Checked that more than once also. But it'll idle just as smooth as any Evo I've ever had.
It will won't run well in that mid range either. A little spitting back and light spitting and bucking. On power like on the highway no problem. Really light power like parking lot no problem. In between like running around town and it just isn't right.
Even the bike starts good the choke cable has no affect on idle speed also. Either hot or cold pulling the cable out or pushing it back in doesn't change the idle. It for sure is a Harley plunger and spring on the end of the cable. The cable itself could be anything since it was just an old one thrown in a box. But if Harley parts are on the end I dind't think it made any difference if it was a Harley or a Mikuni cable. If that is wrong please let me know.
I'm about ready to just give up on this old carb. It's really clean and looks brand new but looks isn't all there cracked up to be. Someone before mentioned some aftermarket carbs before. Cheaper than Harley I assume so how good do they work. On Amazon I saw stuff anywhere from $85 to about $200 but they all look the same. Same stuff with different sellers just trying to make more or si there actually a difference?
Someone also mentioned doing an S&S. The bike already has a Ness Sucker air cleaner and would like to get to keep that and the stock outer cover. I think that leaves only the CV and the Mikuni as options. Unless someone has any other thing I might try on this carb it's maybe time to shift gears and recommendations on the carbs.
Just had a new thought. It did start cold realy easy. And the choke cable never changed the idle. Even though I know it's a Harley nut and spring and plunger on the end of the cable how would the bike behave if the choke was never getting closed? Could a choke problem cause it to not idle low enough when backing off the idle screw that some of those hole would stay uncovered by the butterfly? And would a choke problem affect that mid range spitting and sputtering?
If using the choke cable has no effect, then you have a big clue right there I think. Can you remove the cable and post a picture of it?
What do the plugs look like?
-JW
Can take the carb back off tomorrow to remove the cable. It is definitely the Harley nut, spring and plunger. The Mikuni nut is smaller and the spring and plunger came new with the jets I ordered at the dealership just to make sure they were right.
The elbow was on the cable. I've got nothing to compare against to know if a Mikuni cable's elbow or the total cable travel is different between a Mikuni cable and a Harley cable though. I've had Mikuni carbs on other bikes a long time ago so this spare cable in the box could have come from anthing.
If this was a problem the way its behaving it seems like the plunger wouldn't be doing in all the way. So it'd be like the choke is always on. I could see how that would keep me from being able to slow down idle speed enough that the butterfly might not ever clear those air holes and that would keep the mixture screw from doing anything. Would the choke being open cause the mid-range sputtering and spitting though?
https://www.mikuni.com/fs-choke_cable.html (https://www.mikuni.com/fs-choke_cable.html)
That link helps. I have a harley nut and plunger. Don't have springs to compare so not sure. Have a Mikuni cable. By what is written at tht link this could account for the choke always being open a little. I understand how that would affect the way the bike is starting. If that's going on the idle would be higher right? So maybe that affects the ability to use the mixture screw and get any change? But would that cause the mid range spitting and sputtering?
I don't want to spend another several dollars for a complete cable kit like the Vtwin kit I found online if not pretty comfortable it'll solve things. With the money alreayd spent on the old carb if I spend much more will have spent what some of the after market carbs cost. So rather than buy a cable I could just a carb that includes the cable with it. Some of them do.
I think my new choke cable from Harley was something like $11. Not sure what they are now. That choke cable may or may not be causing your mid-range issues, but either way it probably should be fixed..
Just looked it up in Ronnie's, cable, enrichener, $12.99
Quote from: speedzter on August 08, 2019, 04:08:18 AM
https://www.mikuni.com/fs-choke_cable.html (https://www.mikuni.com/fs-choke_cable.html)
Thanks for that link. My I have the Mik knob and cable. But on mine, the knob is tight in the fully in position, no slack at all. Now I'll go in and adjust that.
:up: for unintentional help
Quote from: SixShooter14 on August 08, 2019, 07:54:23 AM
Quote from: speedzter on August 08, 2019, 04:08:18 AM
https://www.mikuni.com/fs-choke_cable.html (https://www.mikuni.com/fs-choke_cable.html)
Thanks for that link. My I have the Mik knob and cable. But on mine, the knob is tight in the fully in position, no slack at all. Now I'll go in and adjust that.
:up: for unintentional help
Good idea.
Chip, that may be all you need to do, adjust the cable.
The cable is just the cable though. Not the pieces on the business end down inside the carburetor. Fortunately I know for sure my plunger and nut are Harley. The spring I can fuss with if I have to since the Harley spring is shorter. I'll count the rounds on the spring and go from there working from the pictures.
Grabbed a cable at the same indie shop that had the ignition kit. He also had a good used piece of the seal and elbow at the end just in case mine are different. Now I know for sure I've got all Harley parts except now knowing for sure on the spring. Can work with that though. All the pieces this morning were 20 bucks. That is cheap by Harley standards so I can live with that! Have a little bit of real work to do but will try swapping the cable yet this afternoon. Wish the old bike luck.
Progress. It's raining now though so do not know everything.
Swapped the cables and have now have obviously Harley parts end to end on the choke cable. Now obviously have choke function too. Works just as you would expect it to.
At first thought still had no mixture control though. Maybe it's supposed to be this way but I still don't really like how it works. It does at least work a little though. The engine won't die until idle is down just over 550. Scary slow. At 800 still no mixture function. At 700 not either. At about 650 begin to notice response to the mixture screw. It's not a huge response but it's definitely reacting. So adjusted the mixture with the engine idling in the 600-650 range than put the idle speed back up where it belongs.
When the rain stops later will do a test ride and see if the mid range is the same or if its better. Boy I'm hoping for better because I don't know anything else to do.
You should adjust that mixture screw at 1000 rpm.
Yes. I know this. But at 1000 the mixture screws has no affect. At 800 it had no affect. So I just kept chasing it to see if it ever would. It finally did so I did what I could than ran the idle back up. After getting a chance to run it a bit will try it again. Right now that's what it gave me though.
Just back from a 30 mile ride. Going to call it progress but not success. Don't think I'm going to chase the problems more though. Think now its time to ride it regularly with some See Foam in the fuel and see what happens.
Getting it up to temp and riding it a bit helped some. It was idling with a warm engine at 1000 when I left. When I got back it was at just over 1200. Readjusted and still didn't get any response from the mixture screw at 1000 but if I turn it down to 700-750 do feel a slight response to mixture adjustment. That's better than it was and coming my way. Will ride it a few tanks full and check it after each one.
Choke works fine now. The bike starts immediately. I mean like first crank. That part is really really good.
Slow speed handling is still fine. Highway riding even better than it was. Much more responseiveness and snap. Whether it's carb changes or the new ignition system I don't know but it is a lot more responseive to the throttle.
Mid range is better than it was. After the first 10 miles or so much better than it was. Still not nailed down yet. Coming off throttle it will still occasionally sputter. It's not a decel pop out the back its a sputter out the carb. Mid range load got this very light a couple times too. It's not as harsh as it was and its a way less often but it is still there. The bike is ride able now without really worrying about it.
Plan right now unless someone has good ideas that are better is to ride it and see how much that cleans or helps. A few tanks full before handing it over to the nephew unless the bike gets worse and makes me do something else to it. Will also check gas mileage to see if that tells me anything too.
Glad the choke is working correctly.
The symptoms now sound like too rich at closed to 1/4 throttle. Have you looked at the plugs? And how did you set the float level? And did you happen to look at what slide needle is being used?
-JW
Jets are 45 and 170. Plugs looked good. Didn't appear real rich at all. They were replaced in the last couple days though so it's new ones in there now. The needle that was in to begin with was an aftermarket adjustable needle that had no washers on it and a little bent ring. I put in a new stock piece. One that I had in a baggie here was 28025-03.
Float was set putting the carb on a stack of shims to get the angle then looking for .450". That's how I've always done it. Have handled the carb and opened it up a couple times since setting it. So could have bumped something. Don't think so but definitely could have.
Also, this carb is one with the drain hose in the bottom. It's never dribbled any fuel.
Quote from: JW113 on August 08, 2019, 05:50:03 PM
Glad the choke is working correctly.
The symptoms now sound like too rich at closed to 1/4 throttle. Have you looked at the plugs? And how did you set the float level? And did you happen to look at what slide needle is being used?
-JW
I agree.
If it were my bike, I would now try a 42 low speed jet, then I would add the popular sportster needle.
Quote from: Evo160K on August 08, 2019, 10:56:45 PM
I agree.
If it were my bike, I would now try a 42 low speed jet, then I would add the popular sportster needle.
Have a 42 that was in it previously so can try that. What is the difference in the Sportster needle?
It sounds like you have the FM, and are adjusting the float to spec. Very good.
The question that I have now, is that if you found one of the aftermarket tuning kit needles in it, what else was done? Lighter spring? Drilled out hole in slide?
The problem seems to be centered on the low speed circuit. The way the CV is suppose to work, is at idle, the throttle plate is mostly closed, all of the fuel is supplied by the idle jet. A/F ratio for idle is via the idle jet screw. That part does not seem to be working correctly. Then, going from idle to just off idle, the transfer jets supply the fuel by way of the low speed jet. That circuit also seems to be not working correctly.
In order for both idle and low speed circuits to work, they need an air supply that's provided from a passage from the front of the carb in the lower air horn area, called the air bleed. If this is plugged or restricted, the idle and low speed circuits won't supply fuel correctly. If you have the FM, it will show pretty clearly the air bleed path through the carb. If you happen to have the carb off again, it might be helpful to eliminate that as a potential cause of this problem.
It sounds like your main circuit is working well. So regardless of the needle, main jet, diaphragm spring, it is getting the fuel it needs past 1/4 throttle. So I'd be less worried right now about that circuit, and focus on the low speed circuit.
Just to ask the question, the accelerator pump is squirting a nice steam of fuel down the carb throat when you twist the throttle, yes?
-JW
Yes. Accelerator pump is obviously working. And the things you mentioned are what I've come to understand reviewing diagrams of the carb. Even that drilled out hole thing I've seen referenced. That maybe something still isn't cleaned out is why I was thinking about just riding it some with See Foam in the fuel. Hopefully that would help. As for that drilled out hole sometime in its life I dont' have anything to compare against so just don't know.
What i do when this happens is get another set of eyes , to look at the carb , its just that some times you over look the problem thats looking at you in the face,under standing how they work will guide you to the problem? a compression test will tell you if there are any valve leaks causing undue vacumme issues,make sure butter fly hasnt been drilled,your vacumme port is capped if it has one , or not leaking at other end ,vos, cheers barny
Quote from: chipthedonkey on August 09, 2019, 07:12:19 AM
Quote from: Evo160K on August 08, 2019, 10:56:45 PM
I agree.
If it were my bike, I would now try a 42 low speed jet, then I would add the popular sportster needle.
Have a 42 that was in it previously so can try that. What is the difference in the Sportster needle?
The sportster needle is slightly thinner in the straight section, the p/n is 27094-88. If you want to read an excellent article on CV tuning, try to find the article in American Iron Magazine by Joe Minton (a CV tuning expert and former technical editor/writer? for American Iron) entitled "By The Numbers." I trust him completely, he's helped me several times tune my CV's. Once he had me sand the anodizing off of a portion of a Harley needle.
You'll find some excerpts in this thread: http://xlforum.net/forums/archive/index.php/t-1091101.html
The only problem with the Sportster needle is finding one. I remember looking for one about 5-6 years ago and had no luck. I used a CV Performance needle instead, and ultimately I used a small brass washer (#4 I think) under the stock needle, and it worked much better than the CV Performance needle.
Lil Chief
All good advice and thanks. Some of the Joe Minton article I'd actually already found while going through all this. Today the carb was bigger than me though.
Rode the bike about three hours today. Started same as always. Ran the same as always. About an hour in the issues seemed to fade a bit. Then for about an hour both on the road and going in and out of some small towns it gave no hint of a spit or a sputter. Had just about convinced myself it was going to iron itself out when it all started acting up again. I will admit to calling it a few names I wouldn't say in church.
It runs so good on the road and sometimes at other times. The one tank I filled today got 45 mph. But this slow and midrange cutting out isn't going to go away. I've got no other eyes to share it with and why I know I'm no expert the basics I can get apart and back together. There's just nothing else to do that I know that I know how to do to this carb. And if I start buying more parts to just eperiment with I'll end up having spent more than I could buy a carburetor for.
So I through up the white flag when I got home awhile ago. Went to Amazon and bought somehting. It'll be here Sunday. Will hope it's not some offshore junk and will open it up before installing. Just to make sure I'm using jets I want and probably also swap out my known new tube and needle holder and the needle I've got now just because they are known things with a Harley part number. Basically I'm buying it to get a body that's not years and years old and that set for a long time and had god knows what done to it before I started working with it.
Wish me luck on Sunday!
make sure your electrics are okay , plugs coil,etc and charging okay , no loose terminals ,check leads , ohm test them ,some times you think its the carb but its else where , keep trying ,
Quote from: barny7655 on August 09, 2019, 08:08:55 PM
make sure your electrics are okay , plugs coil,etc and charging okay , no loose terminals ,check leads , ohm test them ,some times you think its the carb but its else where , keep trying ,
Few nights ago did complete ignition system change. Coil, cam sensor, plugs, wires and the harness between it all. Took off the stock parts and went to a single fire system. Had all the connectors and connections in my hand and checked them all.
The bike does start easier with the ignition change. It's a obvious difference. I think it's a little more snappy overall too. But the spitting and sputtering behavior has been exactly the same before and after the ignition parts was changed.
chipthedonkey,
Just for fun, can you run the bike on the road in 5th gear at a steady 2500 rpm and open the choke a bit, then tell us what you learned.
I'd also like to know how it acts with the 42 low speed jet in it while doing the same test above with the choke.
Quote from: Evo160K on August 10, 2019, 10:30:32 PM
chipthedonkey,
Just for fun, can you run the bike on the road in 5th gear at a steady 2500 rpm and open the choke a bit, then tell us what you learned.
I'd also like to know how it acts with the 42 low speed jet in it while doing the same test above with the choke.
At this point I'm sorry but I can't. Though I did run it continuously for awhile on the road at about 2700 +/- 100. At that level of load it never spit and sputtered but I thought twice in like 20 minutes I felt that slight surging that I would often feel before it did.
Can't do any more testing with it right now though. The old carb is back off the bike and apart waiting for Amazon to show up sometime this afternoon. Came inside about 20 minutes from pulling it back off the bike to get ready for the delivery. I'm keeping fingers and toes crossed this will finally make it good. Thank you.
Ok good things happened today. The new carb was took apart. One jet was 190 and other had no mark on it at all. Put it back together using the new slide, the needle and needle holder that came with the new carb, 42 and 170 jets and the tube that was with the new parts I'd got along with the 42 and 170 jets from the dealership.
Bike just like before fired up easy. Barely spins over to get started. Then had a bad moment. After letting it warm up just a bit and setting the idle the mixtrue screw on this one is doing something but not much. At an idle speed of about 800 there's a little adjstment. Worried all the rest of the problems would still be there but headed out for a ride anyway.
Everything else is fine. The bike behaves great in all riding conditions. Highway, on a parking lot, town riding and it is all good. Ran it long enough to check mileage on one complete tank of gas and it got 46.5.
I'm so happy it's finally running decent I'm willing to just live the mixture not adjusting right right now. At least the bike runs without bad behavior and gets the kind of mileage that suggests eveything is at least pretty close. It's not perfect for some reason but it's so much better than it did. I'm taking that for now.
The only thing I noticed that wish was different is that whatever had been done to the old carb not counting its midrange problems it did have a snappier throttle response. It was 45 and 170 and it just pulled a little harder when you twisted it taking off or accelrating. The new carb is ok. It feels like a stock Evo. It just don't pull quite as hard today as the old carb did. It's not a big difference but there is some. That is something to chase for another day though. The bike really is ride able and reliable for my nephew now. It'll probably go to him and my brother in a couple weeks.
I wish I knew what was going on with the old carb. In 20 or 30 years a lot could have been done to it though. Things could have crudded up or warped. I'll never know. The new carb even it's just a donor for a new carb body was noticeable better as soon as pulled out of the driveway though. The little shudder and surge and the spit and the sputter never even think aobut happening. There's no decel pop either. Pulled the spark plugs afer the 250 it got rode today and they look good too.
Congrats on getting it set up, your nephew will have a great time with it.
Quote from: Hossamania on August 11, 2019, 06:07:42 PM
Congrats on getting it set up, your nephew will have a great time with it.
Thanks. I'm really happy it's better. Nice to have the old man's bike returned to life after so much time and knowing the nephew will be using it.
I almost wish hadn't spent almost as much on different little carb parts as I did buying the surprising cheap carb on Amazon. Learned a lot messing with it over and over though so that might it worth it.
After he rides it awhile I'll have to start a new thread. It's been a long long time since I hopped up an Evo. Have to start a thread on today's best choices to improve the stock carb and cam choices and whatever. Anything but oil. No oil threads please!
Before this tread completely dies if anyone has a suggestion on the mixture issue please share.
It's a new but not OEM new carburetor. 42 and 170 jets. Idles and runs fine. But the mixture screw does nothing notice able at 1000 rpm and you can begin to adjust the mixture at about 800. It will idle all the way down to the scary speed of about 550 or 600 before it dies.
Ignition system is new. Intake and carburetor seal are new and I checked the flanges on a machinist's table for flat. Can spray starting fluid at the seals from the right side of the bike and the RPM never changes. Can do it from the left side and almost never hear a change but it's hard when doing it from that side for the carb not to suck in just a little bit. So unless it's really obvius I never trust sprays from that side to tell me anything.
The bike runs good enough with normal evo gas mileage so I'm not going to open it back up again right now to chase the mixture control. But sometime later I will so any ideas can just be saved until then.
Just as a comment on your quest for chasing the perfect combination to get the running "right", I too have been chasing a minor issue on my TC.
My combo runs, starts, idles, etc very nicely.
Only issue I have is less than stellar gas mileage. I'll blame the combination of motor, carb, muffler choice that probably contribute to that. I did a little test ride today after changing mufflers AGAIN to see any difference. Had to increase the idle speed a little due to a little more restrictive mufflers.
I will not be playing with my jets, bike runs,starts, etc as it should. I'll leave it alone and just smile as I pull through a turn and accelerate crisply ahead without any drama or hesitation or any bad manners. It just "sounds" right!
Sometimes the "wrong" combination makes the bike run perfect!
JME
:missed:
Totally agree. Sometimes the enemy of just fine is trying to make it better. I'm kind of at that place right now with this bike. It is fine. It's actually a pretty snappy little stock evo that looks like it is going to get good gas mileage too. Especially for an almost new rider with not very much experience it is plenty of street bike.
How is the quality of the new carburetor? I have seen them on amazon and ebay but you are the first one I have heard actually getting one. Kind of surprises me there is enough demand for someone to manufacture new ones but is it also comforting to know inexpensive replacements are available if they are decent quality. I am finding a flood of decent aftermarket, NOS, or lightly used parts online and that is helping me to keep a 20 year old very high mileage bike going pretty well for next to nothing. I almost never go to a dealer anymore, and I am certainly not the kind of customer that keeps Harley profitable.
Glad you have gotten it sorted out, Chip.
Clear back in reply #1 of this thread, I did mention the knock off Chinese made carb option. I too bought one, using it on my Ironhead, nothing really bad to say about them. I guess more of a philosophical concern than anything else. But if it works, it works.
:beer:
cheers,
JW
Quote from: JW113 on August 13, 2019, 08:27:12 AM
Glad you have gotten it sorted out, Chip.
Clear back in reply #1 of this thread, I did mention the knock off Chinese made carb option. I too bought one, using it on my Ironhead, nothing really bad to say about them. I guess more of a philosophical concern than anything else. But if it works, it works.
:beer:
cheers,
JW
I rememberd you mentioning that and that's what sent me to Amazon to look. Found what seemed to be identicle parts for low as $80 to as much $200. Figuring I was going inside of any of them to check what jets were in and just look it over the one I bought was $90. The one I chose was based more on who could ship out to get to me on the weekend based on when I was ordering that night.
For both of you in the last couple of posts talking about the impression of the carb, it's ok. Decent looking casting. No ugly edges. Smooth where it's supposed to be. Flat surfaces. Nothing really to complane about.
The float setting was a way off. The float pin was not a compression fit. The bottom cap holds the pin just fine though. The only thing I had to do to use it on the bike was run a tap through the three breather holes. A 1/4" bolt wouldn't go in more then the first couple threads. A metric bolt that was closest to it wouldn't go all the way through either though. So ran a 1/4" x 20 tap through the holes and they cleaned up fine. The threaded ends go through and tighten up just fine. It feels ok.
Quote from: chipthedonkey on August 12, 2019, 03:51:50 PM
Totally agree. Sometimes the enemy of just fine is trying to make it better. I'm kind of at that place right now with this bike. It is fine. It's actually a pretty snappy little stock evo that looks like it is going to get good gas mileage too. Especially for an almost new rider with not very much experience it is plenty of street bike.
Chip, after reading all of the post on this thread,I think no one mentioned the throttle shaft holes. If they are a little loose fit, air will get in there, and cause the mixture screw to not respond. Check your old carb for this problem, and let us know... Thanks and happy motoring,
I am surprised that none of us, including me, thought of that.
kk
Quote from: Tynker on August 13, 2019, 05:56:17 PM
Quote from: chipthedonkey on August 12, 2019, 03:51:50 PM
Totally agree. Sometimes the enemy of just fine is trying to make it better. I'm kind of at that place right now with this bike. It is fine. It's actually a pretty snappy little stock evo that looks like it is going to get good gas mileage too. Especially for an almost new rider with not very much experience it is plenty of street bike.
Chip, after reading all of the post on this thread,I think no one mentioned the throttle shaft holes. If they are a little loose fit, air will get in there, and cause the mixture screw to not respond. Check your old carb for this problem, and let us know... Thanks and happy motoring,
I didn't think to mention it in here but had run in to that with worn out carbs on cars before. Even bored and bushed a few. So actually did check that out on the old carb body. Unfortunatlely it was ok too.
Just because the new foreign knock off carb is new doesn't mean something couldn't be going on there though since it's mixture isn't as reacting as I'd like. So sometime when have it off again will look at that. Thanks for making me think of it again.
Leaky throttle shafts can usually be found with the "spray test". Just sayin'!
Just for sake of conversation... anybody familiar with the backwards bubble test?
-JW
Quote from: JW113 on August 14, 2019, 07:35:26 PM
Leaky throttle shafts can usually be found with the "spray test". Just sayin'!
Just for sake of conversation... anybody familiar with the backwards bubble test?
-JW
Yeah, even before doing a wiggle test or breaking things down to measure I squirt. Both the old carb and new carb aren't affected. The bike is still running great though. So I'm still calling it a win!
Quote from: chipthedonkey on August 12, 2019, 03:13:17 PM
Before this tread completely dies if anyone has a suggestion on the mixture issue please share.
It's a new but not OEM new carburetor. 42 and 170 jets. Idles and runs fine. But the mixture screw does nothing notice able at 1000 rpm and you can begin to adjust the mixture at about 800. It will idle all the way down to the scary speed of about 550 or 600 before it dies.
My EVO pilot/idle/slow jet mixture screw behaves similarly to yours, which is normal. To find the optimum setting on the mixture screw, set the engine idle as low as it will go after the engine is up to operating temperature. Then rotate the mixture screw in and out to find where the engine idle increases. At the position where the engine idle just begins to increase, turn the idle screw out a half turn and you're done.
Jason
Quote from: Norton Commando on August 16, 2019, 05:04:51 AM
My EVO pilot/idle/slow jet mixture screw behaves similarly to yours, which is normal. To find the optimum setting on the mixture screw, set the engine idle as low as it will go after the engine is up to operating temperature. Then rotate the mixture screw in and out to find where the engine idle increases. At the position where the engine idle just begins to increase, turn the idle screw out a half turn and you're done.
Jason
Thanks for the confirming report. That's exactly where mine is now and its right where I'm choosing to be happy with it.
This may be a bit late, but I had a plunger at the end of the choke cable leaking, and the mixture screw was unresponsive. Changed that little plunger for a new one and it cleared up, and I picked up a couple mpg's.
This was on a bike I had bought new, so I know it's entire history.
If you want really nice throttle response from a carburetor Evo, try the Mikuni HSR42. Nice smooth throttle response, but that slide rattle was right at the frequency where I still hear really well.
Quote from: Princess Butt on August 17, 2019, 03:29:30 AM
This may be a bit late, but I had a plunger at the end of the choke cable leaking, and the mixture screw was unresponsive. Changed that little plunger for a new one and it cleared up, and I picked up a couple mpg's.
This was on a bike I had bought new, so I know it's entire history.
If you want really nice throttle response from a carburetor Evo, try the Mikuni HSR42. Nice smooth throttle response, but that slide rattle was right at the frequency where I still hear really well.
When you say it was leaking are you talking about the plunger not seating well in the carb or the rubber seal behind the nut that screws in to the carburetor or something else?