HarleyTechTalk

Hey guys,
Just completed my '02 Fatboy build, 95ci big bore, fresh set of '09 heads, CR575 cams, DTT ignition and basic supporting mods. Carb was rebuilt with a full rebuild kit

I started it today for its first heat cycle with the choke (enricher) out all the way. Starts and runs...  But as soon as I start to push the choke knob back in and try to hold the throttle slightly open, big puffs of black smoke come out the exhaust and it just comletely dies, even if I give it more throttle....

Runs smoothly with choke on full
Runs horribly, black smoke then stalls when the choke is pushed in.
???

DTT  set to  #2 #3 #0  for first 3 dials
46 pilot jet
195 main jet
CV Performance needle
Float level (angle) checked before reassebly
Tried a/f mixture screw at 1 3/4 turns out to 2 1/2 turns out - no improvement at any setting.

Any help would be appreciated because I need to get it running well enough to do a break in run.
Thanks

First look at the plugs. Then check compression.

Quote from: Adam76 on October 27, 2021, 11:03:29 PM
Hey guys,
Just completed my '02 Fatboy build, 95ci big bore, fresh set of '09 heads, CR575 cams, DTT ignition and basic supporting mods. Carb was rebuilt with a full rebuild kit

I started it today for its first heat cycle with the choke (enricher) out all the way. Starts and runs...  But as soon as I start to push the choke knob back in and try to hold the throttle slightly open, big puffs of black smoke come out the exhaust and it just comletely dies, even if I give it more throttle. It simply will not run without choke on full.

DTT  set to  #2 #3 #0  for first 3 dials
46 pilot jet
195 main jet
CV Performance needle
Float level (angle) checked before reassebly
Tried a/f mixture screw at 1 3/4 turns out to 2 1/2 turns out - no improvement at any setting.

Any help would be appreciated because I need to get it running well enough to do a break in run.
Thanks

The symptoms your bike is exhibiting is not attributable to the jetting package or the position of the idle mixture screw. I suspect an electrical issue.

Quote from: HD Street Performance on October 28, 2021, 05:10:07 AM
First look at the plugs. Then check compression.

Thanks will do. I don't have the compression testing tool, but I can try and get hold of one.

Do you think the compression may be too low or too high?

Quote from: turboprop on October 28, 2021, 05:54:26 AM

Quote from: Adam76 on October 27, 2021, 11:03:29 PM
Hey guys,
Just completed my '02 Fatboy build, 95ci big bore, fresh set of '09 heads, CR575 cams, DTT ignition and basic supporting mods. Carb was rebuilt with a full rebuild kit

I started it today for its first heat cycle with the choke (enricher) out all the way. Starts and runs...  But as soon as I start to push the choke knob back in and try to hold the throttle slightly open, big puffs of black smoke come out the exhaust and it just comletely dies, even if I give it more throttle. It simply will not run without choke on full.

DTT  set to  #2 #3 #0  for first 3 dials
46 pilot jet
195 main jet
CV Performance needle
Float level (angle) checked before reassebly
Tried a/f mixture screw at 1 3/4 turns out to 2 1/2 turns out - no improvement at any setting.

Any help would be appreciated because I need to get it running well enough to do a break in run.
Thanks

The symptoms your bike is exhibiting is not attributable to the jetting package or the position of the idle mixture screw. I suspect an electrical issue.

Ok thanks, where do you suggest I start looking for electrical issues?

Come on, impossible via internet. You are pretty thorough. I would start with checking all of the grounds, voltage drop at the starter and the power input into the module and at the coil. Would also check resistance from assorted places on the the bike to the negative terminal.

It could be a vacuum leak but I doubt it. I had a similar experience last summer. I had an issue with the clutch in one of my FXRs, ended u pulling the inner primary case and rebuilding a bunch of stuff over a few months. When I fired up the bike it ran like "Potty mouth", the AFR was all wrong, like way out of wack. Would only run with the choke and would not take throttle. What was it, I failed to connect the chassis to drive train ground strap. On an FXR it is under the transmission between the frame and the trans case. I simply missed it because the build took so long. The engine had all the symptoms of a fuel issue, the onboard AFR even confirmed it was extremely lean. Once that ground was restored everything went back to normal. Learning definitely occurred in my garage that week.

You will find it.

Ok thanks Turbo, my symptoms match exactly what you've described...
electrical issues are my least favorite problems 😁 but definitely appreciate your advice.

I know that I did take the starter motor out to replace the starter clutch during the build - maybe I did something wrong there?

Cheers

Any chance it could be a damaged / broken / pinched diaphragm in the carb? That was the only thing not replaced during the carb rebuild??

Cheers

Quote from: Adam76 on October 28, 2021, 04:22:04 PM
Any chance it could be a damaged / broken / pinched diaphragm in the carb? That was the only thing not replaced during the carb rebuild??

Cheers

I doubt it. But now that you said it, you aren't going to sleep until you check it.

Yeah, because if it runs "smoothly" on full choke, then it can't be the diaphragm, right? Otherwise it wouldn't run properly choke or no choke... is that right?
Thanks

You know you want to do it.

Double post

With the bike off and ignition off,  when I twist the throttle fuel is squirted in, but the slide does NOT move up at all.... is this normal?
Thanks

I'm no expert on reading plugs but this rear cylinder plug doesn't look too good.

Quote from: Adam76 on October 28, 2021, 09:59:43 PM
With the bike off and ignition off,  when I twist the throttle fuel is squirted in, but the slide does NOT move up at all.... is this normal?
Thanks

Yes, the slide is vacuum operated, the bike must be running for it to operate. Does it move with the throttle while running?
If you reach in and lift it (not running) it should move easily, but you should hear or feel a little vacuum resistance, or air pump effect. A damaged diaphragm usually causes a lean condition, not a rich condition.

What settings are you using on the DTT?  5/5 is a good start initial timing and slope, setting 1 for multispark. 6100 rpm limit, setting 1 for that. Don't worry it being so high, you're not going there. Yet.
As turboprop said, check your wiring and grounds again.
Was the float properly set in the carb?
A compression test is a good idea to at least eliminate that as an issue.
Make sure the battery has a full charge.
Make sure your MAP sensor on the intake manifold is plugged in.

Quote from: Adam76 on October 28, 2021, 09:59:43 PM
With the bike off and ignition off,  when I twist the throttle fuel is squirted in, but the slide does NOT move up at all.... is this normal?
Thanks

Yes.

I would pull the plugs, ground one, the metal body, connected to wire and spin it over. What does the spark look like? Fat and red? Thin and blue? Autoshop 101 I know not sexy but it would save some time maybe.

Quote from: Adam76 on October 27, 2021, 11:03:29 PM

Tried a/f mixture screw at 1 3/4 turns out to 2 1/2 turns out - no improvement at any setting.

Any help would be appreciated because I need to get it running well enough to do a break in run.
Thanks

If turning your mixture screw with no change on a fully warmed engine.  It's a good sign the pilot isn't letting in enough fuel to maintain idle. 

Quote from: Hossamania on October 29, 2021, 04:38:01 AM
What settings are you using on the DTT?  5/5 is a good start initial timing and slope, setting 1 for multispark. 6100 rpm limit, setting 1 for that. Don't worry it being so high, you're not going there. Yet.
As turboprop said, check your wiring and grounds again.
Was the float properly set in the carb?
A compression test is a good idea to at least eliminate that as an issue.
Make sure the battery has a full charge.
Make sure your MAP sensor on the intake manifold is plugged in.

Thanks Hoss, I'll adjust the ignition settings.
When I rebuilt the carb I thought I did a thorough job of checking the float was properly angled.... I didn't adjust it. The battery also was checked and has good voltage and CCA.

I'll have another look at the MAP sensor on top of the intake manifold.

Cheers

Quote from: hrdtail78 on October 29, 2021, 08:58:39 AM

Quote from: Adam76 on October 27, 2021, 11:03:29 PM

Tried a/f mixture screw at 1 3/4 turns out to 2 1/2 turns out - no improvement at any setting.

Any help would be appreciated because I need to get it running well enough to do a break in run.
Thanks

If turning your mixture screw with no change on a fully warmed engine.  It's a good sign the pilot isn't letting in enough fuel to maintain idle.

Hey hardtail, thanks for the reply. The engine has only run for max of 30 secs because it will only run on full choke - so no where near reaching fully warm operating temp.
Cheers

Quote from: HD Street Performance on October 29, 2021, 08:15:59 AM
I would pull the plugs, ground one, the metal body, connected to wire and spin it over. What does the spark look like? Fat and red? Thin and blue? Autoshop 101 I know not sexy but it would save some time maybe.

Thanks, I'll give this a go. Electrical stuff is not my forte 😁

Can you elaborate on exactly what I do for this test ? Pull both plugs? Ground only one, what do I do with the other one?

Thanks, sorry for the stupid questions.
Cheers

Quote from: turboprop on October 28, 2021, 07:33:00 AM
I had a similar experience last summer. I had an issue with the clutch in one of my FXRs, ended u pulling the inner primary case and rebuilding a bunch of stuff over a few months. When I fired up the bike it ran like "Potty mouth" the AFR was all wrong, like way out of wack. Would only run with the choke and would not take throttle. What was it, I failed to connect the chassis to drive train ground strap. On an FXR it is under the transmission between the frame and the trans case. I simply missed it because the build took so long. The engine had all the symptoms of a fuel issue, the onboard AFR even confirmed it was extremely lean. Once that ground was restored everything went back to normal. Learning definitely occurred in my garage that week.

You will find it.

Yeah, that's sounds exactly like what's going on. I've checked the ground from the neg battery to the frame and the ground that goes under the oil tank attached to the starter. All seem good... just found out it's a 5 week wait to get a booking with the top two indy harley techs in my city. What is the ground strap you're taking about with your fxr? Maybe I'm still missing something.

Quote from: Adam76 on October 30, 2021, 05:42:23 AM

Quote from: turboprop on October 28, 2021, 07:33:00 AM
I had a similar experience last summer. I had an issue with the clutch in one of my FXRs, ended u pulling the inner primary case and rebuilding a bunch of stuff over a few months. When I fired up the bike it ran like "Potty mouth" the AFR was all wrong, like way out of wack. Would only run with the choke and would not take throttle. What was it, I failed to connect the chassis to drive train ground strap. On an FXR it is under the transmission between the frame and the trans case. I simply missed it because the build took so long. The engine had all the symptoms of a fuel issue, the onboard AFR even confirmed it was extremely lean. Once that ground was restored everything went back to normal. Learning definitely occurred in my garage that week.

You will find it.

Yeah, that's sounds exactly like what's going on. I've checked the ground from the neg battery to the frame and the ground that goes under the oil tank attached to the starter. All seem good... just found out it's a 5 week wait to get a booking with the top two indy harley techs in my city. What is the ground strap you're taking about with your fxr? Maybe I'm still missing something.

On an FXR there is a large, braided ground strap that attaches to the crossover on the frame and to the transmission. There is a 5/16" bolt that is accessible from the right side of the bike that goes through the transmission case and threads into the inner primary case. That is the point of attachment on the drive train. The rear cross member on an FXR also serves as a mount for the kick stand stop. The ground strap terminal is sandwiched between two internal and external star washers and is attached to the rear crossmember with a 5/16" bolt.

This is a brief explanation why this ground affected the ignition system but allowed the engine to easily crank over. In item form, the FXR has a cable that goes directly from the negative terminal on the battery to a bonding point on the inner primary case, near the starter. The ignition module is grounded to the frame. There are a bunch of wires grounded to the frame, but without that cable between the frame and the drive train the path to the negative terminal is gone. In my case, the bolt that attached the cable between the frame and the transmission was just sort of sitting in the hole, not even threaded in. It had just enough contact to allow the starter relay to apply power to the starter. It also provided just enough to get the engine to run, but was sporadic and when throttle was applied the engine would die. Plugs looked rich, AFR gauge showed lean, etc. All indicators were that it was a fuel problem. I foolishly chased it.

Good luck.

Thanks turbo,
I checked all my grounding wires that I could find - all seemed good except the one coming from the voltage regulator that grounds itself to the rectifier mounting bracket.

But I don't know that was the issue.

Thanks again for your help.

What, if any mods were done to the carb before the build? I think you may have a big air leak and the only way to keep it running is with the enrichener out full. The plugs look stinking rich and that is not a way to break in a new motor. Check the spark and if cranking with the one plugs body grounded, both out, produces a fat red spark move on to the carb for troubleshooting. What intake seals were used? What intake flanges were used?

  Did you use the the new style intake flanges 26993-06 for the 2009 heads on your 2002?

Quote from: HD Street Performance on October 30, 2021, 06:16:52 PM
What, if any mods were done to the carb before the build?

Thanks for the reply,
when I rebuilt the carb, the bike was running ok with no carb issues. I replace the  keihin pilot 45 and main 190 with 46 and 195. I replaced the stock needle with the CV Performance needle. No other mods were noted the slide was not drilled. 

I think you may have a big air leak and the only way to keep it running is with the enrichener out full. The plugs look stinking rich and that is not a way to break in a new motor.

100% agree with you.  

Check the spark and if cranking with the one plugs body grounded, both out, produces a fat red spark move on to the carb for troubleshooting.

Yes, this is what I will do next

What intake seals were used?
What intake flanges were used?

The grass were of an '09 Heritage  - so I used the '09 intake flanges and the rubber seals that they use. I also used a new intake to carb seal. I can't imagine where the big leak is - unless it is the carb diaphragm not seated properly inside the carb.

Quote from: 02fxst on October 30, 2021, 08:25:26 PM
  Did you use the the new style intake flanges 26993-06 for the 2009 heads on your 2002?

Yep used the later model flanges. 👍

I took the carb off and opened it up again and i think I've found my problem ....

I had the needle (6) installed on top of the plastic spring seat (5) instead of below it. This effectively means my needle was way up and causing a super rich condition.

I'm going to put it back together and see what happens.

Cheers

GOT IT !!

Such a small rookie error.

Thanks to all who gave me advice and put up with my novice understanding.

  :oops:

:chop:

Makes sense, glad to hear you got it fixed.

5/5 on the ignition is the stock setting, it may cause detonation as you go forward. It should work fine for break in as you are not putting a hard load on the motor. Mine is running 1/2 now.

Quote from: HD Street Performance on October 31, 2021, 06:26:26 AM
Makes sense, glad to hear you got it fixed.

Thanks 👍

I took it out for a 50 mile break in run. It seemed smooth and strong, but about half way through I noticed a bit a white smoke coming out the pipes.

So I pulled the plugs when I got home -- Front was very light,  and the rear was still a little too dark.

My DTT was set at multi spark and 5 / 5 on the dials.

I'm assuming the front cylinder is too lean, but how did you fix that if
the rear is running already too rich??

Should I go up a size in my pilot jet to 48?

Thanks again

Quote from: Hossamania on October 31, 2021, 07:01:56 AM
5/5 on the ignition is the stock setting, it may cause detonation as you go forward. It should work fine for break in as you are not putting a hard load on the motor. Mine is running 1/2 now.

Thanks Hoss, I started on 5 / 5 for the 50 mile break in run, I didn't exactly baby it is you know what I mean... but I couldn't hear or feel any detonation. Then again I suppose you don't always hear it, and my motor is not stock? So I'm looking for a better setting. Maybe 2 / 5 ?
Cheers

Tough call on the settings without putting some stress on the motor, but 2/2 or 2/3 would probably work fine. 2/5 brings the timing in a little quick, may be a little too much on your modified motor, but hard to say without a dyno, or at least some hard riding. If you didn't hear obvious pinging, it's probably fine though.
As far as the plugs, make sure your plug wires are good and tight at the plugs and coil, and not touching anything that could short them.
With 50 miles on it, it is pretty much broken in, Hopefully you occasionally ran up and down in gear to put "reverse" pressure on the rings to help seat them.
Change oil, change plugs, and head back out. Pull the plugs after a short ride and read them again. If that rear one keeps getting exceptionally dark, it may need a compression test as long as all electrical elements are ruled out. Front one looked ok, rear was fuzzy picture.
How did it run? Feel strong, smoothe?

Quote from: Hossamania on October 31, 2021, 08:44:30 PM
Tough call on the settings without putting some stress on the motor, but 2/2 or 2/3 would probably work fine. 2/5 brings the timing in a little quick, may be a little too much on your modified motor, but hard to say without a dyno, or at least some hard riding. If you didn't hear obvious pinging, it's probably fine though.
As far as the plugs, make sure your plug wires are good and tight at the plugs and coil, and not touching anything that could short them.
With 50 miles on it, it is pretty much broken in, Hopefully you occasionally ran up and down in gear to put "reverse" pressure on the rings to help seat them.
Change oil, change plugs, and head back out. Pull the plugs after a short ride and read them again. If that rear one keeps getting exceptionally dark, it may need a compression test as long as all electrical elements are ruled out. Front one looked ok, rear was fuzzy picture.
How did it run? Feel strong, smoothe?

Thanks Hoss, plug wires are new and yes it ran smooth and strong which is why I was really surprised at the smoke. I was also surprised by the dark / fouled rear plug and the almost too lean front plug.

I'll try a new set of plugs and 2 / 3 settings for ignition and go for another ride.

Could it be an intake leak?

Cheers

You can spray some carb cleaner around the intake seals while idling, listen for a change in idle indicating a leak. Doesnt take a lot of spray. Don't be fooled by spray being sucked into the carb rather than the seals.
If no leak, or no conclusion from overthinking, change oil, change plugs, ride.

Quote from: Hossamania on October 31, 2021, 09:14:21 PM
You can spray some carb cleaner around the intake seals while idling, listen for a change in idle indicating a leak. Doesnt take a lot of spray. Don't be fooled by spray being sucked into the carb rather than the seals.
If no leak, or no conclusion from overthinking, change oil, change plugs, ride.

👍 thanks

Quote from: Hossamania on October 31, 2021, 09:14:21 PM
You can spray some carb cleaner around the intake seals while idling, listen for a change in idle indicating a leak. Doesnt take a lot of spray. Don't be fooled by spray being sucked into the carb rather than the seals.
If no leak, or no conclusion from overthinking, change oil, change plugs, ride.

Thanks Hoss, I changed the plugs and oil and put another 20 miles on it... spark plugs are still giving me problems -- Front is lean and rear is fouling??

Ignition on 2 / 3 and this is baffling because it runs smooth and strong, no hiccups, no spluttering?

Here are the new plugs after 20 miles.

what plugs ?

Hey FSG, what do you mean?  I can see then a attachments on my screen.  :scratch:

I see your pix, but type and number .....  NGKxxxxx ?

Sorry!  NGK 3932 DCPR7E I was told they are the ones for the TC88.

That plug is correct. Any below will work as well.


ACCEL - Y2418P
Autolite - 4164
Autolite Iridiuim - XS4164
Autolite Platinum - AP4164DP2
Bosch / Platinum - YR6LDE
Champion - RA8HC
Denso Iridium - IXU22
H-D Gold - 6R12G
H-D Platinum - 6R12PP
H-D Standard - 6R12
NGK - DCPR7E
NGK Iridium - DCPR7EIX
NGK Platinum - DCPR7E
Screamin' Eagle - EX12S
Splitfire - SF416D

 :up:

Quote from: Ohio HD on November 01, 2021, 08:31:31 PM
That plug is correct. Any below will work as well.


ACCEL - Y2418P
Autolite - 4164
Autolite Iridiuim - XS4164
Autolite Platinum - AP4164DP2
Bosch / Platinum - YR6LDE
Champion - RA8HC
Denso Iridium - IXU22
H-D Gold - 6R12G
H-D Platinum - 6R12PP
H-D Standard - 6R12
NGK - DCPR7E
NGK Iridium - DCPR7EIX
NGK Platinum - DCPR7E
Screamin' Eagle - EX12S
Splitfire - SF416D

Thanks Ohio, it's not the plug itself that I'm concerned about is the difference between they way they are burning.
Cheers

Might be time for a compression test.
Also, test the spark of each plug (new) for equal flame between front and rear.

Quote from: Hossamania on November 01, 2021, 08:52:10 PM
Might be time for a compression test.

Now I'm starting to worry.   :missed:

Quote from: Hossamania on November 01, 2021, 08:52:10 PM
Might be time for a compression test.
Also, test the spark of each plug (new) for equal flame between front and rear.

So what exactly would a compression test tell me about why the plug is fouling?

Is it likely to be valve related or piston ring related? 

The thing that's bugging me is that is runs really well....

Usually the rear cylinder runs leaner than the front. A compression and leak down test will rule out ring or valve issues, or even the cam chain being off by one tooth. Once that is done, proper spark needs to be established. Since the fuel shares a common manifold and carb, there should not be a big difference in afr, provided your intake seals are good. That leaves spark or cylinder seal being the issue.
Hopefully I'm on track, maybe someone else can chime in and redirect if I'm off base.
Double check your plug wires, make sure tight connection at the coil, no rubbing anywhere, maybe even put the old ones back on for a test ride.

Put a new set of plugs in it and ride it a while, say another 50 miles then post the plugs photos ground straps visible. It is time to change the oil.
As Hoss said, compression test is wise.

Quote from: Hossamania on November 02, 2021, 05:28:00 AM
Usually the rear cylinder runs leaner than the front. A compression and leak down test will rule out ring or valve issues, or even the cam chain being off by one tooth. Once that is done, proper spark needs to be established. Since the fuel shares a common manifold and carb, there should not be a big difference in afr, provided your intake seals are good. That leaves spark or cylinder seal being the issue.
Hopefully I'm on track, maybe someone else can chime in and redirect if I'm off base.
Double check your plug wires, make sure tight connection at the coil, no rubbing anywhere, maybe even put the old ones back on for a test ride.

As I look at those plugs, my initial thought is a tiny bit of oil is passing the rings/seals, and there's an intake seal passing a little extra air. I'd pull/inspect/reinstall the intake seals (all 3), adjust the accelerator pump nozzle to squirt directly on the needle, new plugs and try again.

Compression can show up cam timing issues.
What exhaust and air cleaner are you running.
A carb'ed HD will nearly always have the front and rear cylinders running a different mixture, but not as extreme as your plugs indicate.
I would also swap out the needle for a stock one.

Quote from: Hossamania on November 02, 2021, 05:28:00 AM
Usually the rear cylinder runs leaner than the front. A compression and leak down test will rule out ring or valve issues, or even the cam chain being off by one tooth. Once that is done, proper spark needs to be established. Since the fuel shares a common manifold and carb, there should not be a big difference in afr, provided your intake seals are good. That leaves spark or cylinder seal being the issue.
Hopefully I'm on track, maybe someone else can chime in and redirect if I'm off base.
Double check your plug wires, make sure tight connection at the coil, no rubbing anywhere, maybe even put the old ones back on for a test ride.

I'm trying to find someone who will do a compression test / leakdown.... the Harley workshops are booked out for 6 weeks and non Harley mechanics don't want to even do just a simple compression test....

I'm testing the intake seals with a spray bottle of soapy water.

Thanks to all the folks still responding to my thread. I hope I get it sorted. Cheers

Quote from: HD Street Performance on November 02, 2021, 05:39:35 AM
Put a new set of plugs in it and ride it a while, say another 50 miles then post the plugs photos ground straps visible. It is time to change the oil.
As Hoss said, compression test is wise.

Ok thanks. I'm onto my third set of NGK plugs and I've just changed the oil.
I'm going to check the intake manifold for leaks next.
Then maybe another 50 mile road test?
Cheers

Quote from: rigidthumper on November 02, 2021, 05:41:19 AM

Quote from: Hossamania on November 02, 2021, 05:28:00 AM
Usually the rear cylinder runs leaner than the front. A compression and leak down test will rule out ring or valve issues, or even the cam chain being off by one tooth. Once that is done, proper spark needs to be established. Since the fuel shares a common manifold and carb, there should not be a big difference in afr, provided your intake seals are good. That leaves spark or cylinder seal being the issue.
Hopefully I'm on track, maybe someone else can chime in and redirect if I'm off base.
Double check your plug wires, make sure tight connection at the coil, no rubbing anywhere, maybe even put the old ones back on for a test ride.

As I look at those plugs, my initial thought is a tiny bit of oil is passing the rings/seals, and there's an intake seal passing a little extra air. I'd pull/inspect/reinstall the intake seals (all 3), adjust the accelerator pump nozzle to squirt directly on the needle, new plugs and try again.

Ok thanks. I have the air cleaner off  - how do I adjust the accelerator pump nozzle? It's shooting way off  the needle
Cheers

Quote from: speedzter on November 02, 2021, 05:52:25 AM
Compression can show up cam timing issues.
What exhaust and air cleaner are you running.
A carb'ed HD will nearly always have the front and rear cylinders running a different mixture, but not as extreme as your plugs indicate.
I would also swap out the needle for a stock one.

Hey speedzter, how's it going. A/C is std Ness big sucker. Pipes are factory headers and old style SE mufflers (the non restrictive ones).

Yes, 100% there's always going to be a small difference in afr between the front and rear, but this difference is large and also it's usually the front cylinder that runs slightly rich and the rear a tad leaner. AFAIK.

The needle is a genuine CV Performance needle  - do you think that is the problem?

Cheers

I also had the valve guides replaced  when the machine shop did my cylinder boring etc... Do you think it could be a bad valve guide seal?

If the plug was black and oily, then you would suspect bad rings seal? Is that right?

Just guessing on rings and valves without a compression and leak down test.
Rather than soapy water spray, use carb cleaner and listen for the idle to change if the spray gets sucked in. Leaves no mess like soap does. Some use propane instead of spray.
You may be able to find a compression tester for not a lot of money.
As far as the spray jet, if I remember right, it just twists with a pliers, but wrap the jaws to protect the brass, and do not do this until someone else chimes in here to confirm that.
The needle could be an issue, put the stock one back in for a test. Is the CVP needle adjustable? If so, which groove is the clip set at?

Quote from: Hossamania on November 03, 2021, 04:12:32 AM
Just guessing on rings and valves without a compression and leak down test.
Rather than soapy water spray, use carb cleaner and listen for the idle to change if the spray gets sucked in. Leaves no mess like soap does. Some use propane instead of spray.
You may be able to find a compression tester for not a lot of money.

Thank you  👍

Should my accelerator pump nozzle be squirting toward the needle? Mine goes way in front of the needle.

I modified my response to answer some of those questions.
Yes, you want the jet to spray straight into the throat.

I use a small pair of duck bill pliers with a good cross hatch on them. Helps to grab without damaging/crushing the nozzle. I adjust so the spray hits the needle jet/jet needle. I believe this helps break up the fuel and starts the atomizing process before it passes the valves. Hitting the needle also prevents direct spray on just 1 cylinder.
Then again, I eat crayons ;)

Quote from: Hossamania on November 03, 2021, 04:12:32 AM
Just guessing on rings and valves without a compression and leak down test.
Rather than soapy water spray, use carb cleaner and listen for the idle to change if the spray gets sucked in. Leaves no mess like soap does. Some use propane instead of spray.
You may be able to find a compression tester for not a lot of money.
As far as the spray jet, if I remember right, it just twists with a pliers, but wrap the jaws to protect the brass, and do not do this until someone else chimes in here to confirm that.
The needle could be an issue, put the stock one back in for a test. Is the CVP needle adjustable? If so, which groove is the clip set at?

Thanks 👍

I've got carb cleaner to test for intake leaks.
I'm picking up a compression tester today to check both cylinders.
I'm adjusting the pump nozzle to spray directly at the needle.
I'm swapping the non adjustable CVP  needle out to put the stock needle back in.
Then I'm going for another test ride.

Thanks for all the help and suggestions. I'll report back with my findings.
Cheers. 

Quote from: rigidthumper on November 03, 2021, 09:19:02 AM
I use a small pair of duck bill pliers with a good cross hatch on them. Helps to grab without damaging/crushing the nozzle. I adjust so the spray hits the needle jet/jet needle. I believe this helps break up the fuel and starts the atomizing process before it passes the valves. Hitting the needle also prevents direct spray on just 1 cylinder.
Then again, I eat crayons ;)

How do those crayons taste? 🤪

Thanks for the details, I'll get to it later today.
Cheers

Quote from: Adam76 on November 03, 2021, 04:38:00 PM

Quote from: rigidthumper on November 03, 2021, 09:19:02 AM
I use a small pair of duck bill pliers with a good cross hatch on them. Helps to grab without damaging/crushing the nozzle. I adjust so the spray hits the needle jet/jet needle. I believe this helps break up the fuel and starts the atomizing process before it passes the valves. Hitting the needle also prevents direct spray on just 1 cylinder.
Then again, I eat crayons ;)

How do those crayons taste? 🤪

They make for colorful poops!

OK, figured it would at least cost me an hours labour for a compression test,  so I spent the money and bought a compression tester.

Results are interesting -
Front 180psi
Rear 190psi
I would have thought it be the other way around?

Are they about the numbers I should be expecting?

Thanks

That much deviation could be a difference in the number of  cranking hits, the battery level ( which one tested first), a little wet residue, or a wet cylinder wall. No big deal at that percentage actually.  Try a dry and then wet test with a large (automotive) battery jumping it and see if they even up a bit.

With those plugs run so short amount of time and the rear so dark I think you may have ring #2 upside down and that's oil not fuel discoloring the plugs. Pulling the pipes and looking in the exhaust port will tell the story.

What intake and exhaust?  I have seen 90 degree air cleaners that do not play well with carbs.

Quote from: hrdtail78 on November 04, 2021, 07:42:58 AM
What intake and exhaust?  I have seen 90 degree air cleaners that do not play well with carbs.

Post #57, std Arlen Ness Big Sucker

Quote from: HD Street Performance on November 04, 2021, 06:26:51 AM
With those plugs run so short amount of time and the rear so dark I think you may have ring #2 upside down and that's oil not fuel discoloring the plugs. Pulling the pipes and looking in the exhaust port will tell the story.

Thanks HD, I'll pull the rear pipe and have a good look.

From checking the end of the rear muffler, it appears to be dry, black soot rather that wet oil.

I suppose dry black soot is better than wet dark oil?

I'm happy to pull the heads off and have a good look.... but I can't get another set of .030 Cometic head gaskets anywhere. Out of stock.

Thanks.

Quote from: kd on November 04, 2021, 04:46:50 AM
That much deviation could be a difference in the number of  cranking hits, the battery level ( which one tested first), a little wet residue, or a wet cylinder wall. No big deal at that percentage actually.  Try a dry and then wet test with a large (automotive) battery jumping it and see if they even up a bit.

Thanks kd, I'll do another compression test later today.... what is a dry test vs a wet test?

Thanks

Quote from: Adam76 on November 04, 2021, 04:06:20 PM

Quote from: kd on November 04, 2021, 04:46:50 AM
That much deviation could be a difference in the number of  cranking hits, the battery level ( which one tested first), a little wet residue, or a wet cylinder wall. No big deal at that percentage actually.  Try a dry and then wet test with a large (automotive) battery jumping it and see if they even up a bit.

Thanks kd, I'll do another compression test later today.... what is a dry test vs a wet test?

Thanks

Wet test is done after the dry test. It involves putting a squirt or oil in the cylinder and doing the test. Hence the term wet. It will show if its ring or valve related by the readings. If it improves its rings no change look at the valves.   Bob

Quote from: FXDBI on November 04, 2021, 04:44:20 PM

Quote from: Adam76 on November 04, 2021, 04:06:20 PM

Quote from: kd on November 04, 2021, 04:46:50 AM
That much deviation could be a difference in the number of  cranking hits, the battery level ( which one tested first), a little wet residue, or a wet cylinder wall. No big deal at that percentage actually.  Try a dry and then wet test with a large (automotive) battery jumping it and see if they even up a bit.

Thanks kd, I'll do another compression test later today.... what is a dry test vs a wet test?

Thanks

Wet test is done after the dry test. It involves putting a squirt or oil in the cylinder and doing the test. Hence the term wet. It will show if its ring or valve related by the readings. If it improves its rings no change look at the valves.   Bob

Thanks Bob  👍

Quote from: FXDBI on November 04, 2021, 04:44:20 PM

Quote from: Adam76 on November 04, 2021, 04:06:20 PM

Quote from: kd on November 04, 2021, 04:46:50 AM
That much deviation could be a difference in the number of  cranking hits, the battery level ( which one tested first), a little wet residue, or a wet cylinder wall. No big deal at that percentage actually.  Try a dry and then wet test with a large (automotive) battery jumping it and see if they even up a bit.

Thanks kd, I'll do another compression test later today.... what is a dry test vs a wet test?

Thanks

Wet test is done after the dry test. It involves putting a squirt or oil in the cylinder and doing the test. Hence the term wet. It will show if its ring or valve related by the readings. If it improves its rings no change look at the valves.   Bob

Bob, if it's valve related and I have to take the heads off.... that means a new set of has gaskets, right?
Finding a set of .030 Cometic head gaskets sent to Australia is proving very difficult.... Out of stock and on 6 month back order.

Cheers Adam

Just checked the intake manifold for leaks..... no visible or audible sign of manifold leaks....

I'm tearing my hair out with this build.

Thanks again to all those who have helped and given advice.

Cheers

Well it's all over now  :emoGroan:

Started up the bike to check for exhaust leaks and then a lot grey smoke was coming  out the rear cylinder exhaust....

Shut it down and then checked the oil.  It was super frothy. Murky dark color and this was fresh oil I put in yesterday.

I think I've done the head gasket? But There's no sign around the base of the head where the gasket sits .... and the compression of the rear cylinder has dropped a touch  from 190 to 180psi.

This is going from bad to worse.

Before you rip into it check for sump oil.  Get it warm, idle for a few minutes, turn it off and remove the plug at the bottom of the crankcase. Measure how much oil comes out.

Right after shutting it off, remove the oil fill cap and listen for pressure escaping. I'm wondering if maybe you got the head breathers assembled incorrectly. If it's building pressure, it could be pushing oil into the chamber and cause at least a couple of your symptoms

 :up: :up:
Pulling the breather bolts while running there should be pressure released, if not I suspect the breathers assembled wrong or the under rocker box gasket backwards, usually blows off the cap with pressure

Quote from: HD Street Performance on November 05, 2021, 09:30:00 AM
:up: :up:
Pulling the breather bolts while running there should be pressure released, if not I suspect the breathers assembled wrong
Thanks, I actually ran the bike the other day with no a/C and no breather bolts and the was plenty of pressure coming out both holes...

or the under rocker box gasket backwards, usually blows off the cap with pressure

Yes, I remember placing the rocker box gaskets the correct way.

Quote from: harpwrench on November 05, 2021, 07:44:25 AM
Right after shutting it off, remove the oil fill cap and listen for pressure escaping. I'm wondering if maybe you got the head breathers assembled incorrectly. If it's building pressure, it could be pushing oil into the chamber and cause at least a couple of your symptoms

Thanks Harpwrench, no pressurised oil filler cap...

UPDATE: 
Took the bike out for a good hour long run. These are the ONLY symptoms I'm getting.

1. Bike starts easy, runs well. No apparent loss of power.

* No intake or exhaust leaks

* Rear cyl has dropped in compression from 190psi to 175psi on compression test. but that could be my battery weakening. ?

2. I'm still getting quite a bit of light grey smoke out the rear cylinder exhaust.

3. Pulling the rear plug after a run, it's still black, almost a shiny sticky residue.

4. Front plug looks good.

5. Same black almost wet residue in the end of the rear exhaust muffler.

That's it, and when I pulled the rear spark plug immediately after the run there was a nice slow trail of smoke coming out the plug hole....

I'm starting to think I'll pull the rear head and replace the rings on the rear cylinder, and while I'm there get the valve guide seals checked, even though they were replaced during the build.

If you have any other suggestions, that would be great.

Rear plug -

If the rings didn't seat there will be visual signs. The second ring may be upside down, my original suspicion.

Couple of things -
First pic in this thread   :up:  Nice neat set up you've got there.
CV, your slide diaphragm looks ok in the pic. I pinched mine one time, the lip was not seated correctly. Bike started and ran ok but would not rev past 3000. It was obvious when I removed the carb top again. Checked carefully for holes or tears, none, so reinstalled correctly and all good. I don't think diaphragm is your problem but won't hurt to check.
Jets, if it was running good at 88" I would have used it as is to run in 95" but I don't think jetting is your problem.
Compression, I thought that should be done at WOT. Bit tricky on a CV to hold throttle grip on full and lift slide at same time. As previously mentioned the slide operates from vacuum when the engine is running. I'm not sure if your compression readings are accurate.
Rings, if one is installed upside down I would replace it. I think you might be ok there because you strike me as being pretty careful but it happens. I'm wondering about oil expansion ring. They are real easy to install wrong.

Pretty hard to tell from words on the internet about smoke issue on fresh build but I think it's going to cost you some gaskets.

Edit: btw that aerated oil in your tank is normal.

Quote from: HD Street Performance on November 06, 2021, 05:06:39 AM
If the rings didn't seat there will be visual signs. The second ring may be upside down, my original suspicion.

👍 thanks  -- stupid question but can I remove it and reinstall it in the correct way? Or do I need to get a new set of rings?
Thanks

Quote from: -deuced- on November 06, 2021, 03:12:40 PM
Couple of things -
First pic in this thread   :up:  Nice neat set up you've got there.
CV, your slide diaphragm looks ok in the pic. I pinched mine one time, the lip was not seated correctly. Bike started and ran ok but would not rev past 3000. It was obvious when I removed the carb top again. Checked carefully for holes or tears, none, so reinstalled correctly and all good. I don't think diaphragm is your problem but won't hurt to check.
Jets, if it was running good at 88" I would have used it as is to run in 95" but I don't think jetting is your problem.
Compression, I thought that should be done at WOT. Bit tricky on a CV to hold throttle grip on full and lift slide at same time. As previously mentioned the slide operates from vacuum when the engine is running. I'm not sure if your compression readings are accurate.
Rings, if one is installed upside down I would replace it. I think you might be ok there because you strike me as being pretty careful but it happens. I'm wondering about oil expansion ring. They are real easy to install wrong.

Pretty hard to tell from words on the internet about smoke issue on fresh build but I think it's going to cost you some gaskets.

Edit: btw that aerated oil in your tank is normal.

Thanks, appreciate your input. I think it's gong to cost me a set of gaskets.  😁 at the very minimum.
If the oil ring is installed upside down, can I reuse it by installing the correct way? Or do I need a new set of rings?
Thanks

Pull the head/cylinder and inspect.
If the only issue is an upside down ring, I would just flip it over and reassemble.
I would reuse everything on my personal bike, but then again I have been accused of being a cheap/lucky SOB :)
If it leaks, then you're down yet again...

You have something wrong in carb. Not electrical issue.
Also, you should NEVER heat cycle an engine these days. You need to load it down almost immediately to properly seat rings. They seat in about the first 20-30 minutes. Miss that window and they never seat in.
Heat cycle and slow 500 mile is old school breakin method

I am in agreement about heat cycles. No idling, the freshly honed cylinders need oil and they get that better at a constant high idle 1500 or so and just a few minutes before getting it on the dyno to fix the mixture (EFI) or on the road for a carbed bike. Do not do any throttle blipping. Control the heat, do the break in in cooler weather. Third gear roll-ons up to 3500 rpm when the motor is warm. Do not use synthetic oil for break-in. A non-detergent oil such as Valvoline VR1 20w-50 or Shell Rotella 15w-40 are fine.

By the way, the new/used crank will need the timken clearance set. Follow the shop manual and it will take a few tools such as a dummy shaft and dial indicator, mag base, and bracket to mount that.

Thanks Motorguru and HDstreetperformance,

It's good to get some clarification on how to properly do the break in on a new engine build.

Cheers.  :up:

Quote from: HD Street Performance on November 23, 2021, 06:37:00 AMBy the way, the new/used crank will need the timken clearance set. Follow the shop manual and it will take a few tools such as a dummy shaft and dial indicator, mag base, and bracket to mount that.

Thanks, I'm guessing that my crank could be used as the dummy shaft to properly set up the timken clearance on the crank I'm going to put in?

When you read the manual it will be more clear.

I forgot to mention in my last reply. If you have a vacuum operated fuel valve, you fuel issue is likely a broken diaphram in the valve causing raw fuel to enter manifold.
Aoso, you can use old crank to set bearing clearance, however they make a tool for that which makes it very easy.

Quote from: Motorguru on November 23, 2021, 04:10:45 PMI forgot to mention in my last reply. If you have a vacuum operated fuel valve, you fuel issue is likely a broken diaphram in the valve causing raw fuel to enter manifold.
Aoso, you can use old crank to set bearing clearance, however they make a tool for that which makes it very easy.

Thanks, Ill look into that.
Cheers

I forgot to mention in my last reply. If you have a vacuum operated fuel valve, you fuel issue is likely a broken diaphram in the valve causing raw fuel to enter manifold.


I'm not sure if I have a vacuum operated fuel valve -- but I do have a MAP sensor on the intake manifold.  :scratch:

Easy to see if it's vacuum operated, it will have a vacuum line! If it's oem, it is vacuum operated.

Also, that vacuum line is often a source of vacuum leaks.

Quote from: Hossamania on November 24, 2021, 04:52:46 AMEasy to see if it's vacuum operated, it will have a vacuum line! If it's oem, it is vacuum operated.

Thanks Hoss,  yes standard vacuum like from carb to petcock.