I have a used 100 anniversary edition FXDL that is running too rich. I have not had much experience with carbureted HD's, so I need a little help. I have checked the air cleaner, noticed that there is residue from the carburetor running down the inside of the air filter housing and onto the filter itself. This coupled with some bad spark plug fouling (black soot) has me wondering if the carb was ever adjusted after the prior owner placed the slipon SE pipes. This bike has 40k miles and runs fine at idle and at 3000 RPM but not so much in the areas between those points. I would pefer to learn and repair on my own, i just hope I'm not in over my head! Any advise or assitance would be most appreciated. BTW the air filter is clean, and there doesn't appear to be any gas in the oil, but I'm getting old, and my sense of smell miight be going along with my eyesight!

 

First thing: putting after market pipes will invariably make it leaner. Most likely the guy put on the pipes and threw in too big a main jet. Need more info on "not so good in between" --- coughing?--- sluggish?--what? . As you apply throttle on a slide type carb, as the slide moves it is attached with the tapered needle which increases fuel flow as the slide is lifted (more throttle), so if it is stumbling it may have too much taper or the needle has been shimmed to make richer quicker. If the main jet is just too big, it will idle but will be too rich through most range until you get up there in rpms. It will still be too rich but you won't feel it as much. If you stick a finger in the exhaust and it comes out really sooty, drop one jet size, (look at the number on the jet in order to go one size smaller)put in some new plugs and go for a putt. After about ten miles of hi way speed, pull the plugs and see if they are still sooty. You need to twist it up a bit to clean some of the loaded up out of the system. You may have to do this more than one time until you get your plugs to be a little darker than cocoa brown. ( inj bikes not included). Also, and this my preference, if the bike is otherwise stock, ( bore, stroke, compression, cams) run the factory spark plugs. So many folks swear by this or that but I've found, over 50+ yrs of wrenching, that the factory tailored that plug for that application and it works fine, and is easier to get a read on when jetting.

 

Thanks so much for the help. Went out and rode a bit, took your advise and changed the plugs, air filter and added some sea foam to the fuel. Ran great for little bit, but started to seem sluggish and not hold the speed on the throttle once I slowed down or the RPM's dropped to below 3000. I pulled the plugs, and right back to being fouled. And not just a little, but quite a lot of black soot. Checked the oil, and smell gas in it, so going to change that. This has an aftermarket K&M air filter on it as well, so the parts guy at the dealer thinks it might have a stage one upgrade on it. All I know is, I bought this from a different dealer, and they swear they went over this bike before they sold it to me. If this was really the case, I will never let them work on it. I'm thinking of pulling the carb and jet, then downsizing to try and get this under control. Any thoughts?

 

One other thought is to check out your enrichner cable, I've seen those cables not fully close the plunger and create all sorts of tuning issues and fouling out plugs almost immediately...

Edit: I found an image of the plunger, if the plunger is sticking in the CV carb and doesn't close completely you're always dumping extra fuel no matter how you re-jet or adjust the air mixture screw.

 

Great idea! I can do that today, sure hope that's what the issue is. Got to admit, little nervous about pulling the carburetor. Was told it can be tricky to get everything back together.

 

I'd rather work on a carb than FI any day Pulling the carb isn't difficult; take your time and look at how it goes together. Throttle cables, fuel line, enrichner cable, perhaps a vacuum line to the petcock, that's all there is to a carb. Depending on the style of A/C you're running they can mount in different ways but it's actually rather simple, do it once and you're already an expert

The throttle cables are usually the trickiest part but take it slow and it will all make sense. The throttle cables are easier on and off with the carb in your hand so you can rotate it slightly...


Edited to add: If that enrichner cable is still original and the plunger is a bit crusty you might be better off just changing it out, they're something like $12 at the HD dealer.

 

When talk downsize, I hope you are referring to the jet size and not the carb. I have 119k on my 02 carbed wg and the cv carb has been quite good. I rejetted after the 95" build, heads,cams etc., and have not had to mess with it since. (note: I was not trying to make a hot rod, just more power though the entire range, yet keep the reliability) Make sure your enricher is working properly, then do the drop, in jet size, as needed. One jet size at a time. Mine came with a 190 jet, and, after the mods it was still too lean with a 192, and being that I have all the jet drill sizes, I opened it up one drill size to get where I wanted it but I don't recommend doing that without all the correct stuff. Btw, I can still get 48 mpg if I drive it nice and 38 if I boogie. Also, keep the a/filter on while doing all your testing, to ensure all is right when in normal driving mode after completion of all the jetting. Hope that helps!

 

From my experience with a 02 Dyna carbed bike. When my slip on mufflers went on, nothing was changed. When my K&N air filter went on and air box went away, then I gained access to the idle mixture screw and made the carb a tad rich. I also added two #40 brass washers( from ACE Hardware) on the needle. That also got rid of the carb fart. There is a good cab guru, google "Joe Minton tuning the CV carb" Another good source is Nightrider.com articles on CV tuning. I've used Joe's advice and haven't had any issues since I modded the carb in 2003. Try to get your carb back to stock and start from there. Idle jet is a #45 and main jet is a #190 jet. An enrichener circuit hanging open will foul plugs and give you those problems. Good luck.

 

Thanks for all the great suggestions! I am only speaking of downsizing the jet, and will just replace the enricher. Someone also suggested that the head temprature sensor might be bad causing it to read that the engine is too cold and needs more fuel. I have not found anything posted about this, so is this another avenue I should explore? Thanks again forr all the help. I am sure learning a lot about my bike, and saving money to boot!

 

Have you adjusted the enricher cable? They are known to 'wander' and need to be checked occasionally.
Have you thought about buying a genuine HD Service Manual (P/N 99481-03A). A man intending to do his own work should have this tool. It will pay for itself quickly. ebay usually has some available. No other 'brand' will do.
Have fun!
Dave