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246
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4/23/2021
Location
NY, NY, USA
I've done many a top end’s but this one is giving me issues. 2023 ktm 125sx ran great before I took it apart. Put it back together ripped around the block bike runs great. I get back to the garage and it’s weeping from two head bolt holes. I tried giving it another little turn but it still weeps. Took it all apart, O rings are not pinched, tried new copper washers but still leaks. Anyone got an idea of what’s up? Much appreciated. 
Install the head bolts in the holes without the head on and check they screw in far enough, you my need to run a tap down the holes to clean them out.
I don’t think it’s a blind hole but I’ll give that a try thanks!
Isn't that a 2-piece design head?
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Yes 2 piece head
Take a metal straight edge & check the cylinder & head for high/low spots on the flat surface. Torquing to 13.3* ftlbs?
The copper head washers are supposed to be replaced because once crushed they will not seal. You can reuse them by annealing them. Heat until cherry red and drop them into water. You can then use them repeatedly using this method.
I did use new copper washers I had but I’ll annealing the old set so I have some extras. Good idea with the sharpie. I checked the cylinder cap on my kitchen counter and it looked good.
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