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Model 50 rocker arm wear/ top of the valves

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Just doing a de-coke and found that the arm on the exhaust valve seems to have wear on the face of where it contacts the top of the valve stem. (Bad enough that a burr was thrown up.).

The manual seem to suggest that these can be replaced, can they?? If so who would supply them?

Also I still have cast iron guides, would it be worth changing these? They don't seem badly worn but I am unsure how slack they should be.

 

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The rocker arm can be refaced if the wear hasn't gone too deep, if it has, it will need building up with hard facing metal and then refacing. Stick with the cast iron guides in the head if you can, Cast iron wears better than bronze guides although its heat transfer is not as good. A lot of damage is caused by ham fisted guide replacement, usually evident when the guides fall out of the head when taking the valves out. Hammering guides out of the head, even if the head is heated usually rags some of the alloy of the head out with the guide, tearing the surface of the reamed hole. Then when the new guide is fitted it is not gripped by the head properly and the problems go on from there. The way to ensure guide removal without damaging the head is to counterbore the worn guide to just leave a thin shell that collapses inwards to facilitate removal.  

 

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Use E0 Petrol

Stop the attack...

 


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