Hi All,

I recently had a 2003 engine installed in my 98. It runs awesome WOT. When I want to cruise in a lower gear (1st or 2nd, more noticeable then in 3rd+) at a constant RPM, say 4K, the bike has trouble maintaining the exact RPM. It jerks back and forth slightly, almost as if it oscillates between 3990RPM and 4010RPM (not sure of exact numbers). My previous engine did not do this at all. I could hold the throttle in one position and the RPMs would not change at all. Any ideas on what could be the problem? On another note, the idle is irregular, oscillating between 1100RPM and 1300RPM. Other then the above, the bike runs great and has plenty of power. I don't really mind the idle oscillation but the other one is kind of annoying. I've searched the forum for answers with no luck.

Tapatio.

 

Vacuum leak

 

Thanks for the input. Will look into that.

 

If you find no air leaks, then it seems like the carbs need tuning properly. Do a synch and get the idle mixtures right and see how it goes then. Every engine is different, so even if you are using your carbs on the new engine, you may find the jetting needs changing. But do the basics first.

 

Sounds like carbs to me as well. Are you using the carbs from the old engine? Telling folks about the air filter, carb set up and exhaust would be a good idea for better advice.

 

Hi All,

So it turned out to be a loose cooling system hose. The bike runs perfect now!

Thanks for your help.

Tapatio.

 

?????That's strange. Cooling system hose to the carbs or somewhere else? Not sure how it being "loose" would cause that. Seems it might leak, but surge?

 

hey tapatio if you get a chance post up which hose. i have a similar condition. if it worked for you maybe it work for me thanks