motor stumbles

[mdendel]

I have a 2004 sportster 4-tec that starts up fine and runs for about 30 seconds or so then stumbles and backfires etc. for about 5minutes then runs perfectly. Sometimes i cant keep it running long enough to clean out. Any thoughts as to the problem??
Matt

 

[gb387]

I always go with the easy try first, new plugs. 4 tecs really like new plugs... Go from there after that.

 

[mdendel]

I will give it a try, thanks

 

[IDoSeaDoo]

Sounds like a fueling issue. I'd pull the pump and see if you maybe have water in there, or perhaps a clogged pump strainer. I'd replace it on principle. How do the plugs look?

 

[Lelandridesrotax587]

Is your low speed needle to rich?

 

[IDoSeaDoo]

Is your low speed needle to rich?

It's a 4tec, those are fuel injected.

 

[Lelandridesrotax587]

It's a 4tec, those are fuel injected.

Oh ya

 

[Digdog]

Usually if it backfires it's an electrical issue, change the plugs first. You can have the coils tested at the dealer, after that it's wiring that could be bad.