So this new project ive got has given me some issues with electrical but thanks to some on here, I was able to get a good wiring diagram. Thanks big time. The bike ran and idled well but the needle was sticking and fuel was running out the overflow so I bought a new needle valve for it and reinstalled the carb. Now I have popping through the carb (backfiring as well). My experience is that its sucking air probably from a leaky carb to manifold gasket. I verified it by spraying some starting fluid near the top bolt and it began to rev. Changed the gaskets twice and still the same thing. Mating surfaces are spotless and smooth. I tried making a gasket out of cork material to thicken it up a little but still pops through the carb. When I took the carb off originally, there were so many gaskets on it that it looked almost like the insulator blocks the S&S carbs used. Was a Heck of time getting it off. Was about 3/8" thick. I of course couldn't used it again as it was messed up bad trying to get it off so with a new paper gasket and clean surfaces also with shorter bolts I reassembled it. Still popping through the carb. I know the S&S Super E's inside and out but this is a Kehin Butterfly carb. Shouldn't make a difference but the manual does NOT show anything like an insulator block and only one gasket. What Going on here? I have a spare Kehin as well and the exact same is happening. Also I did spray starting fluid around the manifold to the cylinders and did not see a change in rpm, not to mention the bike ran well with the exception of the overflow pi$$ing out because of the bad needle valve before I took it off initially. Any ideas?

Randy

 

 

Intake leak, as noted by changing idle with spray. Fix that first. Next, clean out the carb jets. Next, pitch that POS carb and put a smaller CV carb from a later sportster on it. That carb popped when the bike was brand new. It also got 100 MPG in the mountains, but so lean it was dangerous.

 

Beemervet, actually this bike belongs to a 58 year old woman who bought it brand new in 86. A relative of my wifes who asked me to make it road worthy again.

randy

 

I put unleaded gas in my 86 XLH, it popped and backfired like crazy. The dearler told me when I bought it new that the bike uses leaded gas only. I just had to try it for myself.

 

Dr. Hess. Carb is all gone over. New low speed .52 jet installed as well. Accel pump working nicely. I know its a carb leak and was wondering why such a mass of gaskets initially on it. The woman has never had carb work done. She is the original owner. What was the mass behind the carb? I had to literally wire wheel it off the manifold. Like I said it looked more like and S&S Super E insulator block with a gasket on each side. It was made of fiber and looked to be in layers, but the carb worked fine just leaked fuel.

randy

 

It is all good natured fun Here in EVOland we encourage a sense of humor, and somewhat thick skin.
Bless her heart for wanting to ride again, good luck in taking care of the bike.

Dr Hess won't steer you wrong, get her a CV.

 

The problem is it is NOT sealing. im using one gasket. Should there be more, or a spacer block with gaskets: multiple gaskets? It ran fine until I took the carb off to fix the needle. Now rough idle, popping and spitting and even one or two backfires (with fire) lol. id say timing with that, BUT spray staring fluid on top and it revs. I know iron and shovelheads and had S&S but she is on a budget and just doesn't have the money for that or a cv carb. This Kehin works fine, but is sucking air somewhere.

randy

 

OK, on that POS carb, there is an INSULATING SPACER part number 27003-86A, between the carb and the intake manifold. Hard to say from the drawing. Might be 1/4" thick. We took ours off decades ago.

 

#17 in the picture.