I have a 2004 KX500.....Ithas a pro circuit exhaust system with the factory sound silencer on it...it has been jetted correctly and the bike has been running strong.....i just purchased from boyesen new Rad Valves because i have been looking for more low to mid range......i put it on the bike last nite and took it to the beach to test it out..at first my bike didnt want to kick over...but once i got it running it had a hard time at first to stay running......once it got warm i took it in the loose sand and ran it in 2nd and 3rd gear about half throttle but going up and down with it.....all seemed ok.....i did however notice it winds up alot faster.....then i took it in the hard pack and was in 4th about 3/4 throttle and the bike seemed ok.....when i came back to the truck to look it over the bike was idling funny...the rpm's were going up and down a little and when i kicked it over it reved up and stayed there for a minuted until i put it in gear and started letting out the clutch where it would come down....and that when it would idle different... .i have never ran the rad valves before so i dont know how it works or makes your bike run.....like i said before when i was riding it all was ok its just when i let the bike sit and idle it was a little different......
what do you guys think??? i hope you can help me out here i am leaving to go to hang town tomorrow so i would like to figure this thing out.......but do you think it would be ok to ride it like this?????

jonathan

 

sounds like the valve is hanging up, or isnt sealed right..

causing the equivalent (basically) to a vacuum leak..

could be contamination on the reed valve seat, or on the valve itself.. i'd take it apart and triple check that seal and valve integrity, even tho its new.. you never know..

its gotta be relavent to the valve, being that (i'm assuming) the problem startd with just this part replacement..

couldn't be anything else.. check carb seating too...

and welcome to KF bro!

 

i will recheck everything but would it be safe to ride on saturday???? because under a load the bike runs fine it just winds up fast....the only thing i noticed was that it idled funny........i might have to put the old one back on for now which sucks cuz the rad valve was $200.....but my biggest concern is would it be ok to ride just on saturday???

 

I agree with white.....Probably just isn't seated quite properly....... I wouldn't see a prob with riding like that tho, besides having an erratic idle...