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New valves or should I shim it?

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“Got a valve question? Check here 1st before you post”

Did that, and I still don’t know how to solve this. I bought a used CRF250 –05 ridden by a girl who competes in female Swedish Nationals (last year with that bike). Her father a former Swedish pro is doing the maintenance. I got a good impression of the bike and the family. He said the piston had about 7 hours, and the valves about 15 hours, but he pretended he didn’t know the linkage was not 100 %? So I don’t know if I should take the valves hours seriously. But I figure a race bike for a top 10 girl would be properly maintained. I have been riding 20 hours since that. He claimed that he newer shimmed the bike, and as soon as the valves where out of spec, he bough new ones. He also said that I could easily do about 35 hours without valve maintenance. I change the filter every ride, the oil every five-hour, and oil filter every tenth hour.

Today I checked the clearance and of course they where out of spec.

Exhaust valves should be: 0,25-0,30 mm (0.010-0.012 inch):

-Left: 0,20 mm!!! (0.0078 inch),

-Right: 0,25 mm (0.0098 inch)

Intake valves should be: 0,09-0,15 mm (0.04-0.06 inch):

-Left: 0,10 mm (0.039 inch)

-Right: less than 0,05 mm (0.002 inch)!!! I couldn’t get the 0,05 mm/0.0019 inch feeler gauge in, and since it’s the thinnest one, it could be 0,00?

If this guy is honest, and he has newer put in new shims, could I shim it once? Or would you buy four new valves?

This is my first four stroke, and I was very sceptic against them, but now when I own one, I want to do the right thing.

What do you think I should do?

By the way, the bike is running perfect. Always easy to start. Hot days/but cold engine doesn't require choke, only some pushing on the hot start. I guess that's normal?

/Marc :thumbsup:

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If you have to use the hot start when the bike is cold then that valve (rt) is partially open when it's supposed to be closed.

Since you have -0- clearance on that valve it's time for replacement. Personally, I wouldn't bother reshimming unless you need to ride right away.

You'll know if he was lying about shimming the valves when you see what size shim is in the right side.

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Well said TJ. I would just order a brand new 07' head assy. ( complete) and put her back togeather, and run it. Since you get her torn down, might as well install new piston, rings, and top end beaaring, too. Better safe than sorry!!

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Both those guys are right. As a point of referene, the right intake stock shim on my 05 was .188. I had to shim down to a Hotcam 160 on my first go around.

Your first shim job, if that's what it truely is, typically will last you 10 hrs. The second 5 hrs.

I went with OEM valves and springs and had seats recut, but next time it will be an 07 head. Probably a good idea for you like WFO said since you don't really know the history.

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"the right intake stock shim on my 05 was .188. I had to shim down to a Hotcam 160 on my first go around."............................................................................................................."next time it will be an 07 head. Probably a good idea for you like WFO said since you don't really know the history."

Even though mine 2005 is an "X", that is exactly what happend to me. The same shim sizes. .188 to a .160. After shimming to a 160, I got about 2 hours and it was closed up to .003. I put it on the stand and ordered a new 07 head and a new piston. Once that right intake valve starts going, it isn't going to stop.

What they said ^

Good luck!

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I too was in the 're-shim' boat..I too went from a 1.88 right side intake to a 1.60..I've got about 4 hours on that so far and have yet to check it. I just got and RHC '07 head/valves and springs along with a CP piston. Now just waiting on time to install everything. Someone already said it..if you in a bind to ride, shim that bad boy, just understand it's a band-aid on a broken arm. Even if you re-cut the seats, you gonna come out the pocket for valve train. Spend a lot of money now..or a hell-of-alot of money later.

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Well said TJ. I would just order a brand new 07' head assy. ( complete) and put her back togeather, and run it. Since you get her torn down, might as well install new piston, rings, and top end beaaring, too. Better safe than sorry!!

So what is the list of parts that make it complete?

Is it just this?:

http://www.ronayers.com/fiche/200_0433/cylinder/cylinder.cfm?man=ho&groupid=7400&parent=7390

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I too was in the 're-shim' boat..I too went from a 1.88 right side intake to a 1.60..I've got about 4 hours on that so far and have yet to check it. I just got and RHC '07 head/valves and springs along with a CP piston. Now just waiting on time to install everything. Someone already said it..if you in a bind to ride, shim that bad boy, just understand it's a band-aid on a broken arm. Even if you re-cut the seats, you gonna come out the pocket for valve train. Spend a lot of money now..or a hell-of-alot of money later.

Tnx guys! New valves seems like the thing to do. I will avoid the shim thing it seems. I think I will take the oem complete kit (twice the price in Sweden compared to you). Isn't a new 07 head rather expensive though? You mean there's a risk that my head can't be fixed since it's re-cutted before? Or are you not supposed to re-cut at all?

What's the big fear, why will lack of clearance end up in total destruction? Why can't you wait until the bike won't start any more? This is probably so obvious, and have already been dealt with. Sorry for that.

Should I miss my CR125? How much will this cost?

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