Cylinder Head Bolts Stripped!

Quentin2211

New Member
Feb 19, 2019
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0
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I noticed one of the head studs was stripped partially on arrival (I know it was stupid of me not to at least try to contact the seller). As I’ve rode it more, and have had to tighten it again and again, today one head bolt finally stripped out. The thing is, the top threads are M8x1.25 while the bottoms are M8x1. I thought this was kinda odd. This means that I can’t really find replacement head studs because on most, both sides are the same thread. My question is, would it be effective if I tapped the bottom threads on the crankcase to M8x1.25?? Would it work if I tapped the holes to 5/16-18? This way it would much easier for me to get bolts,washers, threaded rod, etc. Btw I’m only 16 so sry if it seems like I have limited knowledge. Thanks
 

Greg58

Well-Known Member
May 1, 2011
4,140
1,032
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Newnan,Georgia U.S.A.
Welcome to the forum Quentin, did the threads pull out of the block or did the threads strip at the top? If its at the top you can order studs from several of the vendors that advertise on the forum. If its in the block you can use a bottom tap to clean up the threads then use some lock tight to try to repair it. Don't over tighten the head nuts, about 12 foot pounds is plenty.
 

daveet6666

Member
Nov 3, 2015
98
8
8
Omaha ne
I.am no mechanic and kept stripping head bolts and my buddy drove 4 bolts with heads on them straight into engine with no nuts havent had a problem since!