400ex knocking

[Stevie-D]

last week i replaced the rings in my brothers 400ex. i put it all back together, started it up only to find out that the timing was off a degree. so i rip it apart again, adjust the timing, and it runs great. only now the engine is knocking somewhere in the head. the only thing that i did was replace the rings, and i can't figure out what the heck could be causing it to knock. the motor was fine as far as noise before the new rings. any ideas about what could be causing this?

[no limit]

i just rebuilt mine, and its doing the exact same thing, does yours do it all the time? warm- cold? idle or wide open?

[TCracin440ex]

valves out of spec proally...

[plkmonster2]

If it does it when it's warm, make sure it is cooling enough, and that you put oil in it.... It sounds like the motor is making extra heat during break in, and causing it to knock.

[TCracin440ex]

no its just the valves are off spec...its a simple problem and an eazy fix....readjust your valves....i think its .002 on the intake and .004 on the exhaust im not sure it might be .002 on the exhaust too

i was wrong its .005 on the exhaust and .004 on the intake

[no limit]

i have adjusted my valves 3 times, all 3 times to those #'s and it still does it, it sounds like a loud hammering from within the engine. im gunna try adjusting the valves one more time maybe alittle tigher and see if it helps

[TCracin440ex]

might have a bent valve...or you might have a bent rod if its a loud hammering

[duke416ex]

A 400 valve lash is .010mm intake and .012mm exhaust, be sure you are using metric gauges.

[TCracin440ex]

wrong bub.....they are .005 and .004...

[TCracin440ex]

http://www.atvriders.com/articles/valveadjustment400ex.html


i dont think they would post faulty information...and according to that article its .005 and .004

[400exrider707]

Im pretty sure you are both right. One is in metric and the other is in english.:rolleyes: :D