Threaded inserts for cylinder head bolts?

[Guy Scheveneels]

Hello,

I have put excessive torque on the long M8 bolts of the cylinder head of a 1989 (1VJ) and the thread of the holes in the cylinder is damaged.
I planned to repair with a helicoil solution, but on the German XT 600 forum I read this is not a good solution.
An alternative would be to use threaded insert with een external M12 thread and internal M8. But there is such a small amount of material around the hole that I doubt this is a good solution.

Any experience with this problem and the solution is very welcome.

Guy

[*Touring Ted*]

I take it you have stripped the thread in the barrel....

Your only solution is to remove the barrel from the bike... and unless you are a decent mechanic/engineer yourself, take it down to an engineers workshop or engine specialist and have them drill out and insert a "TIMESERT" into the barrel.

Helicoils work but they are not 100% reliable on something as important as those big M8's holding your topend together.

Don't stress though, it shouldnt cost too much.. Maybe £20-£30

If there is not enough metal in the barrel then you will need to replace it... simples !

[XT GIRL]

Easy!

YouTube - Time-Sert thread repair

[Lamin Sambou]

Originally Posted by XT GIRL

Easy!

are you sure?..... I've seen your mechanical exploits on You Tube.......

[Pawlie]

There is nothing wrong in using Helicoil for this type of application. Just use long ones preferably two in each stud hole.

Pawlie

[Guy Scheveneels]

Thanks for the rplies and advice.

On the German XT 600 forum several people have put messages that helicoils are not a good solution for this application. I don't know if this is from experience or engineering judgement. Do some of you have experience using helicoils to repair the treated holes for the cilinder head bolts .

A 12 mm insert would be the strongest solution but I fear there is not enough material around the holes.

Guy