Hi,

New to these forums. Fairly new to motorcycles overall. 'Inherited' a 97 Sportster 1200, and has run great the last few weekends. Took on some nice runs, no issues at all. Until....

This past weekend I went to take it for a ride, and things started out fine. Once the engine heated up, it started sputtering real bad and sounded like mild backfiring once the RPMs hit about 2200. At idle everything seems to be ok. If I shut the bike down and let it cool down, its ok again until it heats up, then wants to chug and sputter around 2200. I have changed the fuel, and checked all the battery connections. Pulled the plug wires they are getting good spark, and the plugs aren't fouled at all, so I don't know what to do here. Any suggestions would be great.

Thanks.

 

Could be a lot of things.
Could be the carb has a problem making the motor run too rich, or a plugged gas tank vent, or filter, the timing pickup on its way out, or some electrical problem, relays, connections, coils failing when hot corroded fuse, etc.....

I think someone had the same problem here a few weeks ago, but don't remember what caused it.


Brett

 

I had the same problem,with my 1997 sportster it was the plugs, they looked brand new.

 

After it has warmed up, take a can of carb cleaner and spray the back of the carb at the gasket and where the intake manifold meets up with the engine. small spurts of spray. If it revs up your gaskets are bad. It's a free and easy way to find out if they are bad.

 

Thanks for the replies. Took the carb off and found the fuel inlet was plugged. Blew it out and cleaned out the inlet and bowl. Running like a champ again.