I have a 1992 Heritage Softail and the bike rides great but pops on decel. I know this is a bad thing, right?

I purchased the bike a month ago. Is this a fuel mixture thing? I do have an adjustment screw that has an extension but I have not messed with it yet. As you look at the carb from the air filter it's on the left. I believe it is a Makuni carb. If this is a fuel mixture screw can someone help me to adjust it? I have a 92/93 heritage softail shop manual but it is worthless unless you want to rebuild the carb.

Could this be a new jet thing?

Jeff

 

If you have a Mikuni, that's probably the idle speed adjustment. The mixture screw is also located on the left side, but doesn't have the extension on it. The mixture screw is an air adjustment, not fuel. Out is leaner, in is richer.
Your popping could be from an exhaust leak or it could be a mixture thing. Check your head pipe flange bolts at the heads and make sure they're not loose.
Usually if the popping is caused by the mixture, it needs to be richer. You can try adjusting the mixture screw, but it may need a different pilot jet or even a different needle.
Mikuni has a good tuning guide and tuning manual you can download from their website. http://www.mikuni.com/fs-tuning_guide.html

 

If it's just a slight popping, it's common and doesn't hurt anything. This is assuming the cause is aftermarket pipes or mufflers that are much more free-flowing than stock. If it's got the stock cam it will be very difficult to get rid of ihe popping altogether because of the oddball EPA specs of the original cam. If you've got good fuel mileage, and the bike runs well in general, I'd leave it. If you really want to get rid of it, the best way is a mild cam upgrade.
And your H-D manual is worthless if it's a Mikuni carb. A Keihin carb is stock.

 

As mp said, it is more likely an exhaust leak. You could try to seal things up, at the joints with a high-temp RTV silicone. Slather it on, and when cured, gently trim with a razor for a sanitary install.
Hope this helps.
Scott

 

Thanks all for the help. I will work on it this weekend. My mechanic said it could also be some crap in the carb and he said to use 104 octane boost, so I will see if it runs better along with checking the exhaust for leaks. I love this forum!!!

Jeff