I just bought a 2001 FXDP with 6200 miles on it. It starts ok with the choke, but its real cold natured and misses sometimes intermittently on exceleration, and let of the gas and it pops and snorts bad. Ran some seafoam thru a tank of gas thru the reserve valve, refilled with fresh gas still same problem. Do I need to tune it up or is it a carb issue? Should I getthe carbrebuilt or replaced? Does it just need new jets? I'm not that mechanically inclied but do have a service manual as a guide. Thanks for the help. Rick

 

It could be the carb but if this happened all of a sudden I'd look ate the Crank Position sensor in the frt of the engine by the oil filter, or map sensor in the maniflod.
Good Luck

 

Is it only when the bike is cold?
Does it run well with the choke on or at 3/4?
Do you have after market air filter and/or exhaust?
If yes to one orall thesequestions you need to rejet. Too lean. have a look on your plug first. What's their color?
Gunny.
Belgium.

 

If you are running uncapped pipes and the carb is still virgin it means that it is way too lean. You can rejet or add baffles to the pipes to get some backpressure.

 

Twincam dave your right I looked atthe pipes the baffles have been removed. Just straight pipes. I think theengineis stock. I do like the sound so which will give mebetter performance? and which will be cheaper? I have a service manual but how hard would it be to rejet? which jet/number? I'm not that mechanically inclined but want to learn, but don't want to screw up my bike. If I dont correct the problem will it mess up the bike or has it already hurt it? so much I don't know. Thanks, Rick

 

Rejetting is easy. There is a guide to doing it somewhere out here on the Web and it will give you all the ins-an-outs of re-jetting. For the most part, the carb has two jets- a slow and fast. If I remember right (I've done this on my Dyna), you are going to be changing out the slow one to get more fuel to the engine in the 0-60% (or so) throttle position. The owners manual should tell you how to remove the carb and how to get at the slow jet. IMO you should change only one size up at a time until you get close to what you're looking for and you might have to go 2-3 sizes up to get there. Just be patient and you'll see how easy it really is. The BEST way to do it is to have it dyno'd, but that might get expensive. The above listed article tells you how you'll know when you're close.

Hope this helps..

 

Thanks to all that have replied. I have been getting a strong gas smell after running it and parking in the garage. So today I decide to check it out. There was a little gas seeping out of the rubber boot towards the bottom of the carb. So I had to pull the carb, replaced the inside diaphram on the side of the float bowl, the rod pushes down on it. Pulled thebowl and looked at the jets. I have a 190 and a 45 in there now. Harley parts guy said its a Mikuni HS40 carb. Should I go up to 200 on the main jet? Guess somebody has been in there before. Don't know what else has been done but got it put back together and no more gas leak and the gas smell is almost gone. Glad to have the service manual. Money well spent. Thanks again. Ride safe

 

you should be able to just adjust the slow idle screw, this is the screw on the side of the carb, on the rear cyl side. I don't remember if this is an air screw or a fuel screw, but it will adjust the mixture from about 0-1/4 throttle.

that carb is generally a plug and play, on a stock ENGINE. may just need a little adj on the screw and Idle speed.

 

You can buy replacement jets in kits that step you up gradually to a desired size. I would go up one step at a time - you might jump two on the first try if you thinkthe popping is really bad. I don't agree with the previous post that says you can adjust the slow speed screw to get where you want to be. Be patient, you might have to go through 2 or 3 tries (jets) before you get the right one.

Try this website for more information: http://www.harley-performance.com/ha...arburetor.html

If you leave the mixture as it is (very lean), you run the risk of burning a valve or piston. And the durn things are put out by the factory lean anyway so any combination of a pipe/air cleaner mod will make that mixture even leaner (and you thought it ran hot before??).

If I remember correctly, I had to replace the diaphragm on my carb when I rejetted too- the dry desert really takes it's toll on rubber parts out here!

Good luck..