PROB. WITH C.V. CARB ON SHOVEL

[77flh]

 :wtf:Hello Ya'll.... Just installed a cv carb on my 1977 flh 1200 shovel. She is all stock including the oem mufflers. I just put a rebuild kit in the carb and set her up with a 45 slow jet and a 180 fast jet with adjustable needle in the center position. Used a press on manifold adapter with jb weld which worked great. She cranks great and idles great. the accelerator pump will give her a quick burst resonably well but when i try to just do a slow, progressive throttle up, she acts like she is starving fer fuel and trys to die on me. Then when I quick burst the throttle she backfires and trys to die again. Should I try a 50 slow jet and maybe re-position my needle higher or any ideas from the house here??  This ole dude is gittin' greyer by the minute on this one!! I dont have any manifold leaks that i can tell....Help me out here somebody!!! Anybody??? Thanky in advance.... (goin' fer a beer and think a while)

[catmcaw]

  Try 48/190 with idle screw out 2 1/2 turns. Turn idle screw in or out (after engine is warm) to get the highest engine idle speed, then back screw out 1/4-1/2.

[77flh]

hey thanks there cat!! i will give that a shot today and see what happens. i wil let ya know what i find. thanks.

[CraigArizona85248]

Was the carb molested before you got it? Make sure the slide hole hasn't been drilled oversized. Also, pull the top and remove the slide and diaphragm.  Hold up to a strong light and look for a pin hole or small tear. With the air cleaner off, you should see the slide rise slowly as you open the throttle slowly (engine running of course). I like catmcaw's jetting suggestions too.

-Craig

[Older-twin]

It sounds like it is running lean because that slide is opening up too quickly.  When you are checking out the slide for an oversized hole also measure the spring length.  A gold colored spring just over 5" is a Dynojet spring and will allow the slide to rise too quickly, as does the oversized hole.  The stock spring is about 5 1/2" long and .0015" bigger in wire diameter.  Yo probably have a Dynojet kit in there.  I've read that the stock cv is a great carb the way it is, especially with your mill.

[Hillside Motorcycle]

That Shovel does not have the low speed signal to the carb as would a later model bike, because the head flow is so poor, and the compression is in the tank.
Up the pilot to at least a 48, and a 50/52 is not out of the question, and set the air/idle 3 turns out for now.
That move should have it able to ride, and then you can juggle the main from there.
Scott

[easyricer]

I have a CV on my stock 1200. I'm running a .050 pilot and .195 main, my mixture is set at 3 turns out. I have a sporty needle in it with no shims. Runs great, starts usually within 3 kicks. Warm she starts on the first kick. Carb is JB welded into an S&S manifold.
EASY

[77flh]

 :scratch:Hey thanks for all the replies ya'll. Sounds like good advice from all of ya. At least a starting point since I'm still scratchin' my head. I think the carb has been molested before I got it and the slide hole looks like it has been drilled out to 1/8" or so. (talkin about the vaccum port in the slide.}  Will that change any of ya'lls suggestions before I take her apart again? I really appreciate the help man. 

[76shuvlinoff]

For what it's worth I have heard of guys filling the drilled out hole with JB weld and then drilling to stock size. I don't know if I'd try that or not. I think I would try to pick up an unmolested carb.

and I would check for an intake leak before any carb tinkering. With an intake leak nothing else is relevant.

My jetting on a 93"er is 50 and 195, 3 turns out. Kinda hard to start cold, I think my accel pump is not working or plugged. I'm going to bump the main up next time I'm in there too.

[Doc]

i build around 100 CV carbs for shovels a year. set em to o.e.m. specs. get rid of all the dynojet parts. xl needle / 48/190 jets to start. 2.5 turns out for idle mixture to start. I also do a few modifications as well, but above info should make you run.

[easyricer]

Click the pic, and it'll take you to the album and under each pic is an explanation of what I did.
One thing on CV carbs, they are more sensitive to what Air filter and what exhaust you are running than any other type of carb. Some resistance is needed for the carb to work right. I'm running stock dual crossover mufflers and a stock Evo air cleaner with a foam UNI filter. If you are running shorty drags or a Velocity stack, you may never hit the right combo for a CV.
Just like the length of a pipe affects the performance of a set of heads, the resistance of the pipe will affect the performance of the CV carb. 
NOW that said, you don't need stock mufflers to run it. Just a washer in a drag pipe will do the trick.
To tune a CV carb right, you'll need 3 sets of NEW sparkplugs, a short 3/16 wide screwdriver, and a phillips head screwdriver as well as a sparkplug wrench.
AFTER making sure you DO NOT HAVE ANY VACUME LEAKS, warm the motor up to the point where it's uncomfortable to keep your hand on the rear rocker box.
Adjust your idle to about 1000rpm. Now adjust the idle mixture screw. Turn it out until the motor reaches the highest RPM with just the mixture adjustment. Then turn it back in, counting your turns, to the point where the needle bottoms out (be gentile it can break off in the carb body if you tighten it down after it touches.) Your count should be between 2 and 4 turns out. Less than 2 you need a smaller pilot jet, more than 4 you need a larger one.
NOW change the sparkplugs. Take the bike for a ride. About 5 miles is good. find a nice straight (FLAT) road with a shoulder where you can safely park. Ride it moderately, hold the throttle steady then kill the motor, pull the clutch in and let the bike coast to a stop. Pull out the sparkplugs and get a good look at them. (having a new one on hand to compare to helps.)  You are looking for small tan to brown ring or spots on the white insulator. If it is solid white, no spots or ring, you are too lean and need to either raise your needle (with shims) or get a richer needle. If it is dark brown or black, your needle is too rich.
It could take several rides to get the needle adjustment right. Just remember to replace the plugs for each ride.
Once you have the needle right, find a LONG straight road, preferably with a nice long hill to pull. HIT IT HARD! Wide open throttle until the bike stops accelerating or you chicken out, at that point, again kill the motor, pull over and check the plugs. Now you are still looking for a brown ring or spots. If it's black your main jet is too rich, if it's white your mainjet is too lean.
ONCE you change the main jet, you may have to adjust the needle again. SO once you are happy with your main jet, take a moderate ride again and double check the needle adjustment. If you put in a larger mainjet, you will probably see a darker ring or spot on the plug. as long as it's not dark brown or black you are fine. if it is, then readjust the needle.
AND there you have it. That's how you set a CV (or just about ANY carb).
EASY

[lupe]

HELLO Scott. paul md.-aka lupe and the family here.   Scott, i want to work very hard to word this so i am very clear about a few point,s before i go further. I am not a know it all, i am not many thing,s. i am for sure not YOUR peer or above you. I am beneath you Mr palmer. and i know it, and frankly proud of it. i pursue those i feel to be above me. MY root point without writing a bible.  That mech fact you were good enough to share, that u did not have to, and i for i know can ONLY come from hours of testing etc etc, speaks volumnes to me, and is going to be a tremendous piece of mech info to have in my head when i will very soon help fire a shovel with a cv. The POOR signal. i get that in full. i was NOT aware the cv was hyper sensitive to that. This INSIDE tip u saw fit to share could very well help make or break this particular new build shovel we aim to fire very soon. Does this make sense scott. it helps me more than i can tell u to know that upfront. u are a darn good man and indy to share that i say. tx hillside. just thanks. paul md

[lupe]

 Hi Rudy, paul,---been awhile.  Rudy, its fair to say we have never met, done little or none pm etc and so on right. U and me have kept it all up front here where the whole family see,s it all.  Okay, i have been uh, can i say gone, but not dead, I am going to take time to check back posts about your build. grapevine says she RUNS>  proud and pleased FOR U RUDY. and tx to the hard core htt family that helped u along the way. it,s all good. hey. i will be frank. i am a member here. as many other sites. BUT my true heart and foremost loyalty as it is and should be just as it is here is ya know. over yonder. BUT RUDY, HTT has been VERY good to me. has not draw me down for that, and is what lets me speak from the heart to u now as i do. honest, very very FEW sites do this. htt is among those that do within reason. I respect that, i acknowledge that. and i thank ALL the htt family for that PRivelidge.  bottom line. whats up with your build rudy. hey all have teething pains. i ask about higher ground. FOR example. I am a stone believer in OUTside oil returns FROM the HEADS. not jugs HEADS. in my nobody op/ Mr Kirby. aka prodrag, machined without ? the best mech, and visualize returns that can be done on a shovel. i care about U and if time allows, i ask to learn more about your build in overall. rudy, i just love this chit. thats all there is to it and u also have more than 1 of the elites of our industry with there --ickskinner work and prints all over it. rudy, thats a very cool thing and hard to beat.  done fer now cuz i talk to much. i could go on and on. tx and later RUDY best always Member. paul

[easyricer]

Any progress on that carb? How did it turn out?
EASY

[Hillside Motorcycle]

HELLO Scott. paul md.-aka lupe and the family here.   Scott, i want to work very hard to word this so i am very clear about a few point,s before i go further. I am not a know it all, i am not many thing,s. i am for sure not YOUR peer or above you. I am beneath you Mr palmer. and i know it, and frankly proud of it. i pursue those i feel to be above me. MY root point without writing a bible.  That mech fact you were good enough to share, that u did not have to, and i for i know can ONLY come from hours of testing etc etc, speaks volumnes to me, and is going to be a tremendous piece of mech info to have in my head when i will very soon help fire a shovel with a cv. The POOR signal. i get that in full. i was NOT aware the cv was hyper sensitive to that. This INSIDE tip u saw fit to share could very well help make or break this particular new build shovel we aim to fire very soon. Does this make sense scott. it helps me more than i can tell u to know that upfront. u are a darn good man and indy to share that i say. tx hillside. just thanks. paul md

Happy to lend a hand!!!
Thanks for the kind words as well!!
We are not anyone special, we just know this motorcycles from years of working on them.
Scott

[77flh]

  OKAY.....LET ME START WITH MANY THANKS TO ALL WHO OFFERED ME THEIR HELP!!! I AM VERY GRATERFUL!!! NOW.....AFTER MANY HOURS OF HEAD-SCRATCHIN' HERE IS WHAT I CAME UP WITH. The needle jet on top of the holder will go in two ways....but only one way is right. The larger diameter goes into the carb body and the smaller sits atop the jet holder. Next, I put the o-ring type seals on on the intake and wrapped tite with 2-rounds of electrical tape. Then I put the heavy 2-bolt clamps on and tightened the crap out of 'em. Next I put a press-on type!!!!! manifold adaptor on the cv carb and sealed it with jb weld. Put the air cleaner back on her and VROOOOOMM,MMMMM!!!! TIME TO GITTER IN THE WIND. 2 1/2 TURNS OUT ON THE MIXTURE SCREW, #50 SLOW JET AND #175 HIGH JET AND DAMMIT MAN WHAT A DIFFERENCE!!!! Dont know which prob. fixed it or maybe all of them but this ole shovel runs like a scalded dawg now!!!! THANKS EVERYBODY AND I HOPE THIS DOES SOMEONE ELSE SOME GOOD IN THE FUTURE!!!! '77FLH

[CraigArizona85248]

 

I'd bet the biggest problem was the needle seat being installed upside down in the carb body.

Glad to hear you are up and running.

-Craig

[MikeL]

I was having the lean cough. and at times little high speed stumble Was 45/175 now 48/185 much more ride friendly. Gonna leave it at that for now. Waiting to see if I gas out co riders with the increased hydro carbons.


                                                                                       MIKE

[kink04fxd]

Easy, what kind of air cleaner are you using with that cv?

[easyricer]

Kink, I'm running a stock Softail 7 inch round housing with a K&N filter.
EASY