Sportster Carb Coughing
 

Hello.

I have xl883l 2006. So there is a new problem for me. I have changed spark plugs, its a brand new champion spark plugs. And my carb keeps coughing on cold engine, bt it stops when I pull the enricher. But after warming up engine, it keeps backfiring into carb. and kinda chokes on low rpm. When I rev the engine it is stuttering and then revs. no problems on high rpm when riding.

I have checked for intake leaks, no leaking air. I have changed carb diaphragm. accleretaion diaphragm, noozle. Everything is kinda good. but problem never dissapears.
Do I have to change spark plugs, might it be the fault?


Thank you

Did you try opening up your idle/mix screw 1/4-1/2 turn?

When it gets to operating temp and still coughing is the choke off? If it is I would pull the carb and make sure all passages are clear. If it has sat for any length of time ethanol in the gas will cause problems.

Yes. Idle/Mix screw is properly set.

Yes when engine is hot choke is off.

Has the bike sat for any length of time?

Yes sir. It has been about year. Before that it was working just fine. Then I just changed the spark plugs, cause I could not start on old ones

The description fits a lean condition. If there are no intake leaks, somewhat not enough fuel is reaching the engine. If all the passages are clear, that leaves you with float level, and possibly vacuum leaks. I am no expert I am sure far more knowledgeable members will come to rescue.

If it we're me I would pull the carb and tank. Clean out the tank and clean the carb. Ethanol really is not good when it sits. I would be willing to bet it is fuel related

I would drain fuel tank and carb bowls and replace with fresh fuel to start with. If that does not work then I would go on to cleaning/rebuilding carbs.


Looks like 2 of us posted same thing at same time.....LOL