Last sunday i finished a overhaul on my quad. I put new piston in and had a valve job done and engine runs good but seems to make a slight ticking sound in the top end any help??

 

I'm not sure, but i think on 400ex's the decompression release sometimes gets stuck with one of the valve rockers(?) somtimes and will cause a steady tick. ( I think i read that in Clymer) and i think I either read or heard that when this happens, leave the quad off and rock the bike forward and backwards (in gear and with the clutch out). Give it a try.

 

Ill give it a try in the morning. because it did not tick or make any nose before. it just quit running. then i rebuilt it. would you think the rocker arms would of went bad? its not real loud but i wonder if i should ride it like that?

 

Like I said, I'm not sure exactly what part of the valves/rocker arms that the decompression lever gets hung up on. Although you said you got a valve job, it wouldn't be a bad idea to check your valve clearances too. I would give you the clearance specs, but im up at college, and my manual is at home.
Good luck

 

ok.... so i tried the whole rock back and forth deal... nothin... still ticks?? my buddy said it could be a loos header pipe!!! not sure.

 

sorry man, well it was worth a try. have you checked your valve clearances? take a look at that header, good luck.

 

Hey mine is doing the same thing after a rebuild. I put a 426 kit in mine and it all of sudden started ticking. At first i thought i needed to run higher octane gas than 92 octane. So i ran 97 octane and it still ticks. so when you figure the problem out please tell me what it was thanks.