I bought an 86 FXRS back in October with 39,000 miles on it. With the exception of some chrome, it's basically a stock bike. The problem I am having with it is the carb. This thing is a bear to start and keep running long enough to warm up. My buddy says it's my technique, but this thing won't hold a steady rpm until it has been running a couple of minutes. To me, it acts like it is lean. It will also cough ocassionally when you are cruising down the road at a steady rpm.

My question is, will the carb mod that is shown here fix this problem, do I need a complete rebuild on the carb or would I be better off getting a replacement carb?

I know my way around a Holley, but I've never worked on anything like this carb before.

TIA,

Monty

 

If it is CV (slide) carb, it can be made to work. If its got the
earlier butterfly type carb, get something else.
The best way to go is to put a Mikuni on it. It will work
the best right out of the box.

 

I bought my bike used 2002 FXDWG3 TC88, with some real short pipes that were really blue (lean) about 14"s down the pipe. The CV carb was not modified and the plug was in. I didn't feel like messing with it and bought a Mikuni HSR-42 and a V&H 2:1 Pro and bolted them up and only adjusted the idle speed down about 50rpm. I later tweeked with the idle mixture, but the came back to the original setting.

One thing I don't see is anyone speaking on changes with altitude while riding... The CV carb is probably the best for varied altitude since it componsates for the changes (nature of the carb).

I'm sure that the factory CV carb is good, but there are some many differnet mods that people are doing to them. (Thunder-Slide, 1/4" drill bits, etc.), and all I wanted to do was ride when I got the bike. It was a quick fix for me and I had the money...

Keith

 

I wasn't even thinking about that...It's probably the butterfly Keihin carb, but I haven't looked to verify it. A new carb may be in my future.

 

I believe the 86 had the cv carb and yes, that mod will work along with the proper way of starting the motor also. Try full choke and hit the starter, if a no go , then full choke and one twist of the throttle and hit the start. This is on a cold motor, warm motor would not require as much gas to start.

 

Right now, full choke and one twist won't get anything but a pop. It takes four or five twists to even get it to start. When it does start, the rpm will go way up, then drop and eventually die unless I work the throttle. After several minutes, it will "idle" at around 2000 then work its way up to 3000, if I still have the choke pulled out fully.

 

Check your intake seals https://www.hdforums.com/m_85102/tm.htm

Also the state of tune for the engine, proper plugs etc.

 

I did a visual inspection of the boots as best I could in the limited time I had last weekend. That was actually one of the first things I thought of. I'm in the piston engine aircraft industry and induction leaks are a pretty common occurance. I need to get a mirror and a flashlight to do a good job of it, though.

Thanks for all of the help!

Monty

 

As usual I could be wrong,that being said,The fixed Keihin was 76-89 for B/T.The CV came out in 88 for XL's,1990 for B/T.Take off airbox and see if you have butterfly or slide inside venturi.We will go from there with ideas,Bob

 

I will say you have a fixed Keihin.If your not fat,get a rebuild kit [30-35$].You will need new manifold clamps,the stock ones are no good.There are good AM ones in the books.Thats where your air leak is coming from,unless its the throttle-body shaft[unlikely].Pop out the AF plug and adjust.New air filter if needed.If you can afford 3-400$ for S&S,Mikuni,or a Keihin CV 1992 or later.1999 or later is better yet,do that.The cables are another 100$[roughly].Plus hi-flow kit and adapter if you go the CV route.Good luck,Bob