Hey everyone. im new to the forums. i have a queston for all of you.

My good friend is selling me his 2001 honda 400ex. He just recently put a high compression piston in it and new timing chain. The valves seem to be adjusted right. but the valves tap. they never stop. Hot or cold. you start it and the valves tap. the higher you rev it. the harder and louder they tap. he told me that is normal because of the high compression piston. i highly doubt that is normal. there has to be a way to fix this. does anyone have any good ideas? Please let me know. I want the quad. but not with the valves like that.


thanks, Vinnie

 

Hmm I got the same problem with my 400ex no high comp. piston that i know of cause i bought it used. I've rode it hard at all the dunes on Oregons coast all year with it like that and have had no problems ... Yet. Not sure whats up with it, im in the same boat as you are hopefully someone will let us know.

 

what octane fuel are you running? mabe it isn't combusting at tdc. higher compression higher octane fuel and it might not be your valves that are off. ahhh intake lash is .004 & exhaust lash is .005 if u want to check.

 

all 400ex valves have a tiking noise when there runing its a normal sound . i know mine makes that nois and the more you rev it the louder it gets , my buddies makes the same exact noise and his is a 2004. thats just the normal sound of a 400ex.