powerhead woes


Senior member
May 15, 2009
Cruising area
Mainly the sea -sometimes the air
Boat name
The boat with no name
Boat make
Promax 225
So just swapped my xr2 and promax powerheads on my boat but I nicked the gasket very slightly putting it on and also appear to have stripped a thread tightening one of the bolts. Seems to be powerhead end but not sure if it's the bolt or the thread in the powerhead or both - it was tight and then got real easy!!!

I only need to use it for a little testing and then two races and then I'll rebuild it over the winter properly.

I'm thinking worst case scenario is some leakage of exhaust gas and maybe some power which I can live with.

I really can't be doing with having to take it off again and rethread the hole but I do have a spare bolt.

Thoughts???? Any input greatly appreciated!!!!!
damaged thread in the cylinder block

- it was tight and then got real easy!!!

Better to remove the cylinderhead and check the threads in the block.
You maily have 4 solutions for repairs
check here, in product info.:
timesert is sold by wurth.CO.uk
keensert is very similar to the system CATERPILLAR Technicians use to repair damaged threads.You have a cat dealer in POOLE.
Ask them the avaibility and prices for the 3/8UNC thread repair kit reference
9S-3618 , this kit comes with 6 inserts, so you can repair more damaged threads....
Don't use your engine with this damaged threads, you will blow your cylinderhead gasket very fast, and add some distortions to your cylinder block surface.
Usualy, the threads Inside your XR2 block are 3/8UNC in size, better to check first to make any order of kit anyway.
hope that helps

Cheers Bruno.

Now that its light I can see what's going on - looks like I have actually stripped the thread at the nut end right at the top just when it gets tight.

I can get it pretty tight on the remaining threads before it hits the mashed threads so I'm going to tighten it as much as I can and Loctite it.

It's only for a couple of races and a bit of testing so fingers crossed will be okay!

Thanks for the help


Latest posts