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I have an 86 Softail. Mileage is roughly 60,000. All stock with the exception of drag pipes. Ive owned the bike over a year now, rode it all last summer/fall with no issues.
on to the problem. I first noticed it last year the last time I tried to ride it, anytime Id try to give it consistent throttle it would just die out on me. I limped it the few blocks home with the choke on and it sat all winter. Early this summer I rode it for the first time and it rode great, after visiting my father in law I went to ride it home and it rode like absolute ****, had to ride with the choke on the whole way home. I went through the carb a billion times, replaced petcock, fuel line, and fuel crossover line and did the intake seals and rubber boot between carb and intake. Now it starts great, idles like a million bucks, you can blip the throttle as many times as you want and it sounds awesome, but as soon as you try to give it steady consistent throttle it just falls flat on its face and dies.
The carb is a CV carb, used on `90 and later Big Twins.
I suggest you remove the carb, disassemble and clean thoroughly, check float adjustment.
Remove the plug that is over the mixture screw if it has not already been removed (watch out for the tiny washer, spring and o ring when you remove the jet).
Remove fuel petcock and check the screen.
Replace all the fuel hoses and the vacuum hose for the VOES.
I agree with Dan89FLSTC's suggestions.. and if you have access to a sonic cleaner, as OldEnuf2NoBtr suggests, that will truly clean out that carb, jets, and passages...
I suspect it is dirt working through the carb/tank, or the VOES. That would explain good running at idle and bad running at higher throttle settings...
Also, I hope the plug for the mixture screw has already been removed and someone has adjusted the carb for those straight pipes... from the looks of the pipes in that pic (which may not be accurate), that's been running lean..
Thanks for all the input, Ill try all that stuff. As far as the pipes being blue, they looked like that when i
got them. It had been running really well up to that point.
Also, I hope the plug for the mixture screw has already been removed and someone has adjusted the carb for those straight pipes... from the looks of the pipes in that pic (which may not be accurate), that's been running lean..
Do you have any recommendations for tuning the carb to the straight pipes? Jet sizes and mixture position?
Do you have any recommendations for tuning the carb to the straight pipes? Jet sizes and mixture position?
Can't help with the carb tune for your bike (my engine is a Twin Cam, and built up), but I CAN, and do, recommend getting a set of DK Customs Thunder Torque Inserts. I run Vance and Hines Straight Shots without baffles (so, straight pipes ), and before installing them, there was a significant torque dip off the line (which is typical of straight pipes), the TTIs eliminated it for me.
Do you have any recommendations for tuning the carb to the straight pipes? Jet sizes and mixture position?
Just follow the basic procedures for tuning a CV40 carb... start with the mixture screw and the number of turns will tell you if you need to go up in jet size... and keep going systematically from there
This site is a good place for parts and info on the CV40 carb...
For your reference, I have a 2001 88" with carb. I went stage I (high flow A/C and high flow air cleaner). I kept the OEM jets 45/190, changed the needle to a CV Performance Velocity needle (#402-823), and with about 2 full turns on the mixture screw, it runs awesome... With straight pipes I'm not sure what you will need.
Start from scratch with the mixture screw. If your bike is OEM, the mixture screw has a plug over it (per EPA mandate) taht can be easily removed.. then start tuning..
Good luck.. and have fun with it!
Last edited by hattitude; Aug 26, 2021 at 04:52 PM.
Just follow the basic procedures for tuning a CV40 carb... start with the mixture screw and the number of turns will tell you if you need to go up in jet size... and keep going systematically from there
This site is a good place for parts and info on the CV40 carb...
For your reference, I have a 2001 88" with carb. I went stage I (high flow A/C and high flow air cleaner). I kept the OEM jets 45/190, changed the needle to a CV Performance Velocity needle (#402-823), and with about 2 full turns on the mixture screw, it runs awesome... With straight pipes I'm not sure what you will need.
Start from scratch with the mixture screw. If your bike is OEM, the mixture screw has a plug over it (per EPA mandate) taht can be easily removed.. then start tuning..
Good luck.. and have fun with it!
Pulled carb off again and cleaned everything. Diaphragm under the top cover looks good. The pilot jet looked clogged and shitty. It was a 45 jet, I happened to have a brand new 48 that I replaced it with. Getting the same issue, runs/idles great. Can give it a good hard crack of the throttle but it dies with a nice steady throttle. Unless the choke is on, then you can hold the throttle at a consistent rpm and it wont die.
Pulled carb off again and cleaned everything. Diaphragm under the top cover looks good. The pilot jet looked clogged and shitty. It was a 45 jet, I happened to have a brand new 48 that I replaced it with. Getting the same issue, runs/idles great. Can give it a good hard crack of the throttle but it dies with a nice steady throttle. Unless the choke is on, then you can hold the throttle at a consistent rpm and it won’t die.
Sounds like a dirty carb or worn/bad parts... Did you rebuild the carb with a rebuild kit, or just clean it and put it back together...??
If the pilot jet looked clogged and shitty, you can bet there is some other dirt in passages you can't easily see... sounds like a good candidate for a soak in an ultra-sonic cleaner. At least a total disassembly, good soak in solvent, then pipe cleaners and air pressure to clear out all passages...
I wouldn't have increased the 45 jet if it was starting & idling well, and the mixture screw is open 3 turns or less.... That will most likely just decrease your MPGs, with little to no benefit.... Remember, anytime you change something, it's good practice to readjust the mixture screw..
Make sure the float is set properly, the float valve/seat are good & clean, and the needle jet holder (aka: velocity or emulsion tube) & main jet are clean...
You may need to add a slightly richer needle...
Of course, always double check you are putting things back together properly... I won't go into how I learned that lesson...
Good luck...
Last edited by hattitude; Aug 28, 2021 at 01:05 PM.
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1986 Softail acceleration/fuel issue?
), and before installing them, there was a significant torque dip off the line (which is typical of straight pipes), the TTIs eliminated it for me.
