Dead cylinder

I went out this afternoon to ride, started up my 2004 XL only to find that I have a dead cylinder. I pulled the plugs and both were fouled pretty bad. Any reason why? I don't really drive a lot with the choke.

couple of thoughts

have you changed pipes or air cleaners lately? are you sure that the choke is actually opening all the way? the choke cable might be slipping...how had it been running lately? I'm no expert..but I have an older sportster(84) ....and you would be suprised how minor changes can foul plugs.....what do the rest of you think?

Nope, no changes. That's the funny thing. I hadn't been riding in a few days and rolled it out to warm up while I cleaned out the garage (with the choke on) shut it down, went back out later and the back cylinder wasn't running. That's when I pulled the plugs to find both were fouled. strange thing is that the front was as fouled as the back and that cylinder still ran. maybe a wire went bad?

Fouled

It is not a choke, it is an enrichener, adding more fuel not reducing air flow. When you run with the enrichener on, it dumps raw fuel into the venturi just inboard of the butterfly. The position of the slide is not relevant. If you have an overly rich idle to begin with, plug fouling is easy. Get some new plugs and it should run fine. Only use the enrichener to start and turn off as soon as the bike will idle. Needing to Ride with it part way out is a sign of being lean on the pilot side.

Proper starting technique is nearly as important as jetting is. One way to avoid using the enrichener is to lock the idle a little higher with the throttle lock. Just be sure to fully release it.


A properly jetted CV bike will require some enrichener from a dead cold start but, warm starts and hot starts should rarely need it. IF you do not need the enrichener to start dead cold your pilot is to large.

Thanks, that really helps! I was a bit confused on the function of the enrichener. I always thought that when you leaned an engine the RPM's increase. In this case, is it just the opposite? I did have the HD dealer take a look at the bike just after I picked it up (within 200 miles). It was spitting real bad through the Carb. They told me that they rejetted it and I took their word for it that it was right however, now when I get to some new pipes and air cleaner, I shouldn't have to rejet right?

Thanks all for your postings!