[shawndak089]

But if i let it return to idle then slam it it will go no problem. It revs up to onlly 4-5 thousand then i have to let off the throttle then hit it againand itll go. Ive cleaned the carbs, tuned them, ran new oil and gas lines. Also have brand new head gaskets and changed the filters. It doesnt smoke up and runs great it just has this stumble everynow and then.

 

[shawndak089]

Got it!

I put higher heat dissapation plugs in the engine and it no longer does this anymore.

 

[tv4fish]

I assume you mean you put in a "hotter" spark plug (Went from like a BPR9ES to a BPR8ES? I think your original problem was just "bad" plugs that needed to be replaced, as the difference in the heat range would not cause the problem you described.

 

[shawndak089]

No the plugs I had in were BPR6ES and they were brand new. I put in new BPR8ES but now the problem has came back. Its like the low to mid end power is just gone then i let off the gas and give it full throttle it goes fine. Ive adjusted the carbs on several occassions and still nothing. The heat range actually does matter and can cause pre ignition.

 

[tv4fish]

Yes Shawn - heat range DOES matter - but that has nothing to do with your problem. I think you proved that yourself since you replaced the plugs and the problem is now back . The 6's you had DEFINITELY were too hot for your engine regardless. R U sure you cleaned and re-assembled the carbs correctly? Any obstructions in the air intake? Had the machine sat for a while?

 

[shawndak089]

Yes the machine had sat for about 4 years. This is not my first time working on carbs so yes i put them together correctly. I changed all the fuel lines and oil lines along with the filters. The air intake is fine. Ill give it gas sometimes and it will be pinned and will only do 15 then i let off and do it again and it will take off no problem. Maybe the oil is bad?