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View Full Version : Crf valve help.. pics inside


dangle
12-30-2005, 03:47 PM
I got my crf tore down to the piston today... well I've never messed with valves b4 but to me these puppies look clapped... especially the intake... I can't really understand where the manual is sayin to put the gas to do the solvent test... any help is appreciated...

http://i10.photobucket.com/albums/a139/zombiequad111/MotorTeardown005.jpg

http://i10.photobucket.com/albums/a139/zombiequad111/MotorTeardown002.jpg

http://i10.photobucket.com/albums/a139/zombiequad111/MotorTeardown001.jpg

http://i10.photobucket.com/albums/a139/zombiequad111/MotorTeardown003.jpg


Mike
dork
12-31-2005, 12:15 AM
they want you to pour solvent in the ports and then look for any leakage around the valves into the combustion chamber. also you can't tell how the valves are (except for the leakage test or a leakdown test) until you pull them. look for cupping on the valve face. also look for any pitting or roughness on the valve seat. the crf's usually have intakes that start cupping and sinking into the head. if your clearance tightened up thats most likely. the exhaust seems to last longer. that has titanium valves and if they're cupped, replace them. kibblewhite makes stainless valves that last longer. use their spring kit too with the stainless. if you use titanium, don't lap them.
2muchquad
12-31-2005, 05:25 AM
well just by looking at them i can almost guarantee they have some cupping.i dont know what year your motor is but i know guys that would go through 2 sets in a season.they would only re shim once,after that the valves really start wearing faster:(
Honda TRX250ex
12-31-2005, 03:49 PM
damn i wish my vavles look like that:(
F-16Guy
12-31-2005, 04:17 PM
Yeah, the intake valves have a titanium nitride coating that is notorious for wearing through. Once that happens, they will continue to cup and tighten up on a regular basis. The best fix is to go to stainless, but like dork said, make sure to get the spring kit because the stainless valves weigh quite a bit more.
fitethesystom
01-04-2006, 12:22 AM
RAWFUL!!

I'm scared of CRF engines after what the dealer told me!!

Are those 2 Burnt valves?
stc416rider
01-04-2006, 04:23 AM
Originally posted by fitethesystom
RAWFUL!!

I'm scared of CRF engines after what the dealer told me!!

Are those 2 Burnt valves?

thats what i thought they were
xsr71x
01-04-2006, 06:33 AM
My valves looked much better than that, but I did have the scoring on the head of the piston which is never a good thing.