Needs some help please ! I have a 98 Custom XL1200C Sportster that is running okay while idling. But, when you throttle up it acts like it is misfiring. I had the same problem with it last week. I found some kind of clear substants in the jet. Once I cleaned it out, it ran fine. I road it around 120 miles to work and back. Then it started doing it again and died. Not to start again. I checked the jet and it was clean. I checked the float to make sure it was getting fuel. I checked the spark plugs, which I replaced the last time it did this. I checked the spark, it seemed like a good white spark. Does anyone have any suggestions? I emptied the gas tank but I didn't remove the filter to check it.
Well you have checked the spark and that fuel is getting to carb. I'd take plugs out and clean them, take carburetor off and really clean everything about it.
Check the vac hose to the carb. The piston diaphragm may be cracked. Yes check the accelerator nozzle when throttling to see if fuel is shooting out into the throat. Clean that filter in the tank. could be the lining clogging the filter. Lastly Change the fuel line if old It can deteriorate and mix with the fuel getting into the carb.
Not to jump the thread but a similar condition is happening on a 2004 1200 sporty. The Crank sensor went and the bike wouldn't start. Says he just got it recently. He put on a new sensor and the bike started right up idled fine but when riding says it rode like riding a jack hammer. I had him test for spark in both cylinders it passed. (Removed plug wire while running Engine cuts out on both cyl) moved on to carburetor. Checked vac started the bike with no Air Cleaner Piston rises with throttle. Some noticeable dry black in the throat but not a ton of it. He has a K&N High flow filter element with stock type slip o exhaust) I would think the stock main jet should be ok with that set up. Had him clean the throat of the carb on the bike. Had him adjust the slow jet as it was 3 3/4 turns out and I thought that to be too rich. He still says he has roughness but his idle seemed low to me. Before removing the float bowl to clean the emulsion tube and main jet I informed him I believe it could be the exhaust gasket leaking the intake leaking or the main jet. Here is a picture of his New plugs after an hour run. They are in different states. Can anyone guide me on why one cylinder has more crap on the electrode than the other? Right rear. Left front
I know it,s polite to come back and give results so. He did the test with Carb cleaner. I told him that was no good and can give false results so he did the WD40 and no leaks. I told him to go for the run and get the sea foam. (He lives in PA) I spent all night posting to him how to adjust the carb. He was out 3 3/4 turns I suggested 2 1/2 then 3. He said the bike ran much better no backfiring or stumbling. He was obviously running "rich cold" on 1 cylinder. For now seems the issue has been fixed. Time will tell for sure.
Where is the ignition pickup located and how would you test it?
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