Cylinder Head and Bent Intake Valve

[Zazoos]

Hey Gang,

I have a 2007 Grizzly 660. Previous owner sank and hydrolocked it. Crank was bent and two intake valves were bent.

I replaced the crank, bored cylinder and new piston. I put new valves, springs, and seals in the head and had the machinist check it. The valves were making a good seal. Put the motor back together and it had some valve clatter. I adjusted the valves and the clatter improved, but still was noticeable. After about 20 hours ride time the center intake valve was bent.

Since I did not replace the valve guides, could this be the cause? I am thinking about purchasing a new cylinder head off eBay. It comes complete for $445.00, but it is made by HSUN. What are your thoughts.

Thanks,
Trent

[vamped350griz]

you sure it was your valves you were hearing and not the timing chain??
A worn or stretched timing chain slapping back and forth can sound very similar to clattering valves. It could also throw your timing off causing the valve to hit the piston slightly and bend

[thomasakehoe]

I'd agree with vamped about a likely cause as to bend the valve it would have had to smack something. If the head is new and complete I'd say its a good deal. Just out of curiosity on the rebuild did you use a high compression piston or have the head shaved to straighten etc... Wondering if there wasn't sufficient quench area and the noise you were hearing might have been a bit of contact from the valve hitting the piston and as it bent it may have gotten quieter by it being forced away from the contact spot on the piston.

[Zazoos]

Good thoughts,

I did replace the timing chain when I did the rebuild.

Trent

[Mad Mike]

I have heard that the center valve was a problem on the older grizzly and raptor`s it seems they have a habit of freezing in the guides. give eric at ehs a call his number is in my sig.