[Sollie1986]

Ok, so I just did a routine top end on my 04. Took it to the track and spent about three hours breaking it it. When I went to get on it comming out of a turn it sounded like the head gasket blew and there was a loud clanking noise which sounded like the piston smacking the valves. I went straight home and I started tearing it down.

I can't find anything wrong,

The timing was still set dead on and the cam chain was still tight. I removed the head and the top of the piston was perfectly fine. No marks from valves or any carbon build up. So I pull the cylinder and everything looks perfect. Rod bearing is fine, and the new piston is clean.

So, I start examining the head. The valves look fine, no marks on them. I hold the head upside down and I pour some solvent on the valves and theres no leaks.

I decide to put the thing back together. I kept the valve cover off and I kick it over real slow and there is still something deffinetly smacking inside. I know the vavle clearance is good.

If anyone has anything I should look for that is just flying over my head please let me know. Thanks.

 

[450RRR]

Dang....it sounds like you know what your doing..... I would have thought cylinder breakage or crank bearing issue....(lower rod end).....

but if all of that checked out OK.....maybe it is a flywheel issue? what does it look like inside the flywheel cover? cracked or damaged flywheel? maybe on the other end.....crank gear...or countershaft sprocket/gear....etc....

with the head off....check TDC.....by slowly rotating crank back/forth at TDC.... see if you can notice enough play to 'assume' the lower rod bearing is either GOOD or BAD......



just some things to check...me~

 

[Sollie1986]

Thanks for the fast reply.

Is there a chance one of the valves could be sticking open? If it sticks open the piston would smack it but there wouldn't be any resistance so it doesn't leave any marks.

 

[ZIPS-TRX]

We need more details on what you did on the top end.

 

[Sollie1986]

All i did was a new piston and gaskets. I reshimmed the valve clearance. About the ninth top end i've done.

 

[KyKult47]

ck your comp. release

 

[Sollie1986]

Ha ha, good idea. Whats an easy way to check that?

 

[450RRR]

if there is any carbon build up on your piston.....or even not in MOST cases...... you would see a 'half-circle' ring on the piston where the valve struck........

what 'type' of noise is it making....????

ticking... grinding.... crunching....pinging.... etc....

 

[Sollie1986]

it's more of a clanking than a tick or ping noise. There is a little bit of light brown on the top of the piston, but no sign of and contact. I'll try to get pics of it after work.

 

[sandshots]

i would say check the flywheel.

whats your oil level looking like?


just cuzz its really easy, pull out your oil filter and make sure theres no shavings in there.

 

[lms racing]

Any valve springs broken....cam carrier tight?

Good luck......How does it run,doe it still rev out?

 

[cheapfast450r]

which area of the motor is the noise coming from....top, bottom, which side?

didn't have any extra parts last time did you?/ (jk) lol

where when slowly kikin' over do you hear the noise. could be the cam not seated properly??

just a stab.........good luck

 

[Sollie1986]

the noise sounds like it's coming from the bottom of the head. Everything looks good, i'm out of options it going to a perfessional. Thanks for the help guys.