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CRF 250 vale seat cutting


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Can a valve seat get cut too deep?

I've had mine re cut and I can't get an accurate measurement with my exhaust valve clearances. The rocker arm sits lower than the valve retainer and the only way I can get a feeler gauge in it to bend it.

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Is there a shim in there?

Yeah there's a shim in there. The old exhaust clearances were both .003 so I used a shim calculator and put new shims in, but as the new shims are smaller they seam to sit bellow the retainer. With the engine being at tdc there's a little play in the rocker arm as the manual describes but even then the rocker arm does not come above the retainer.

It's making a noise when started like there is a larger clearance than is needed But it's hard to get a feeler gauge in between them to get an accurate measurement.

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I'm suprised the service manual doesn't give installed height spec. for the valve stem in the head.

One thing is, those are not stock retainers, so maybe try some stock ones.

What size shim is in there, my stock low hour 07 has 2.35mm , if your too far away from that they my be cut too deep.

The shims i put in are either 1.30 or 1.60 can quite remember. It's got ansa motors stamped on the out side of cylinder and I'm pretty sure it's not a stock cam shaft either so I'm guessing it's an aftermarket set up.

In all fairness I spoke to someone from the shop earlier and he has said that I can send it back and they will sort it out for free.

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Can you re use a oem head gasket if it's only been used less than an hour or would you replace it with a new one?

You can but I wouldn't just for the fact you are taking a chance of it not seating, then when you get it all back together and realize its leaking you have to go back through the whole procedure. I always replace them.

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You can but I wouldn't just for the fact you are taking a chance of it not seating, then when you get it all back together and realize its leaking you have to go back through the whole procedure. I always replace them.

After tearing it down I won't be using it again, like you said it's not worth the risk. Just getting it ready to send back ImageUploadedByThumper Talk1416951952.234006.jpg

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  • 2 weeks later...

Is it possible the retainers got swapped for the intake? Memory ( not very good ) says the retainers for intake and exhaust were slightly different? What year is this bike?

It's a 2012 crf 250. To be honest I wouldn't know if they had been switched, I'm still in the learning phase. I've sent it back to the shop that done the head work to check it out for me, just waiting to hear off them at the moment.
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  • 2 weeks later...

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