Parts manual calls for a 1987 FLT to have Keihin (butterfly) carb # 27034-86B. It calls for 1987 FXR and Softail Models to have a Keihin (butterfly) carb # 27029-86B.
What is the difference?

 

Probably jets. But if you have carb problems just get a CV carb and end the issues. The later CV is so much better than the older Keihin.

 

+1 on that!

the cv carb is more easily tuned and modded. ( see nightrider.com for info, bike tech section )

CV carb swap will require new cables and a manifold adapter- about $15 for the rubber "mikuni" spigot adapter.

I did same day dyno runs on my 88 fxr, butterfly to CV and picked up a few horses, better overall operation, power at altitude etc.


If you are stuck on a butterfly, pm me and we can do a deal on my old carb



Mike

 

Recently upgraded butterfly w/ Andrews accelerator pump and am satisfied with performance. Bought 3 carb bodies on ebay, one is the 27029, and two CV's with the thought of eventually changing out. Mainly just curious, they appear the same on outside.

 

I think I have a thunderjet kit for the butterfly new in package too. it adds a 3rd midrange jet.

the advantages to the CV are vast. self compensation for altitude has allowed me to dust much more powerful bikes with S&S or mikuni when we go up in elevation

mike