QuestionI have a 1990 springer that I took to a small local shop when I noticed that gas kept blowing out on my pipes. The bike was running fine, but kept blowing out the gas. The guy replaced the accelerator pump, and the blow back stopped. However, right after the replacement, the bike started missing, back firing, and running rough. I went back to the shop, and was told that the carb needed to now be re-jetted, a prosess he said could take hours, and a couple of hundred bucks. The guy put in a couple of new plugs (the old ones fouled right after I left) and sent me on my way.
I took my bike to another shop, where they re-jetted the carb (I don't think that it was the main jet). The bike ran ok for a few miles, then I noticed the first back fire. I went back about a week later, the mechanic said that it may need to be rejetted again, but suggested that I get an S&S carb to replace it, since he thought that the original Screaming Eagle Carb was just to difficult to set properly. Unfortunately, I do not have 500.00 dollars to spend at the moment. He told me to drop off the bike, and that he thought that it just needed another adjustment, or a different jet. I dropped off my bike a few days ago back to this shop, and after a few days, called him. He now tells me that he doesn't think that it is the jet. This would have went over better, if he had not told me that he hadn't yet had the opportunity to look at my bike. Unfortunately, I really like the guy at this shop, and have bought many accessories from him for mine, and my wifes cycle (though I could have got them online for 20 percent less on the internet). At this point, I am frankly confused. I was hoping that you could offer an opinion as to what the problem might be.
If I take off easy for the first few miles or so, then not make too many quick throttle changes, the bike seems to run ok at times, especially if it is very warm outside. There seems to be a "sweet spot" in the trottle, at which I run with less problems. However, there are times when I "punch" the throttle some to pick up speed, and get a backfire, or several episodes of repeated bogging down, or missing. It is strange. One day I am doing 55 or 60 mph for miles and it is running just fine (give or take a few misses, and an ocassional backfire). The next day, I have repeated problems. I can say that it usually does worse when I am driving in stop and go traffic then it does on the highway. I have tried carb cleaners, gas treatment, and high octane fuel from different stations.
At this point I think that I should have just lived with the fuel blow-back.
Any help, or advice that you can offer would be greatly appreciated!
Thank You, Jerry
AnswerSince your bike was running fine before you it to the first shop (except for the gas blowing out) The I can assumn that it was jettted right in the first place. Jetting does not change as you put more miles on the bike.
I would look a couple different directions for your problem.
First, test the coil and spark plug cables. If you need to know how let me know. A weak coil and plug wires will cause the above problem.
Sounds like, since your bike is worse then before, put the jets back that was in in the first place. The fouling of the plugs leads me to beleave that the jets are to big. I would have the work done by the first shop checked. Doenst sound like he installed the acceralator pump right or it would have run.
You never stated how many miles you have on the bike. You could have a leaking exhaust valve, which would cause the gas blow out.
good luck and happy riding
Mike
