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Valve / Top End Advice

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I just had my valves adjusted for $90. When I went to pick up the bike the mechanic said I need to plan on replacing the valves and rings next time the bike is hard to start. He told me one of the valves required him to change the shim from a 168 to a 140. The other mechanic walked in and told me it was dangerous to ride the bike at all because it could suck the valve through and cause alot of damage. After mechanic 2 left, mechanic 1 said there was only about a 10 chance of the valve sucking through. He said the bike could go from 1 ride to 6 months before the top end needed to be redone.

Sorry for the long post, but I'm now a little concerned about the valves. Is this the standard mechanic doom and gloom (sorry to the mechanics out there)? Is the bike OK to ride? Should the bike become difficult to start when the valve goes out of adjustment? Or should I expect a major malfunction while I'm riding if I don't get the top end redone ASAP? Thanks for the help.

:cry:

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no major malfunctions will take place as long as they put the bike together right...

but it could go 1 ride or could go 6 months before its hard to start again... If you are gonna pull the top end to put on new rings, do a piston while you are in there.

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He told me one of the valves required him to change the shim from a 168 to a 140.

That means the valve face has at least a .005" recession and THAT'S A TON. The valve is junk and any mechanic with an ounce of sense would have advised you not to ride it that way. With that much valve face recession there is a high probability the the valve no longer hits the seat concentricly, which tends to cause a bending motion in the valve stem everytime the valve opens and closes. When that happens you risk breaking the valve head off and having it drop in the engine. You can probably imagine what kind of problems that will cause. If you want to see what it looks like first hand wander over to the YZF250 forum. Lots of pictures posted there, or you can ask the RMZ250 guys about the same things.

It is certainly risky riding it as is. Putting a percentage on how risky without having the engine completely apart to inspect the damage is someone just pulling numbers out of their butt.

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I would be scared...if that thing broke up say, on the run to a triple or something, serious injury could result. I for one know what it feels like to have a broken femur, wrist, shoulder, ribs, and lung, all from one crash. I have enough things to worry about without having to wonder if my motor is gonna blow on the takeoff ramp under full throttle...

...I would make SURe it is fixed right....

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Sounds like a top end job to me, i just went throught the exact same thing on my 04, one month the valves were great, the next month the intake valves had deformed and sucked up into the vavle seats .008, which meant they no longer were closing and the bike wouldn,t start.

Might as well bite the bullet and re-build her before she forces you too the hard way. Put RNC intake valves and spring set in , keep the stock SS valves as they are most likely okay, out new piston and rings in and then bust a lap.

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