New cylinder or repair old one?

[06roadking]

I did a conversion from 883 to 1200 on a 1987 sporty for my kid. He rode it hard right out of the upgrade (approx 110 miles) and the rear head gasket blew. In the process it scorched the cylinder and displaced some of the metal (approx .010" deep and 7/16 in long) by the aft left head bolt. I looked it over and the cylinder sleeve is OK and nothing is warped on the head. I still need to check the cylinder studs for stretch.

My dilemma is do I use some type of metal set to build the area where the metal was displaced?

Do I get the cylinder machined?

Do I suck it up and buy a new cylinder?

Will metal set (Devcon Aluminum based putty) handle the heat?

First and foremost I need to keep teenage sons off the bike until I have ran it for the 500 mile break in.

Any suggestions would be greatly appreciated.

Dave

[Panzer]

If it was I, I'd try having it shaved.
But before you do, I'd make sure you have Clarence in all aspects.
By that I mean, are you using domed pistons, shaved heads, etc.
You shave the cylinder, everything will sit lower on that side.
Make your son pay for it & kick him in the butt.

Panzer

[Ed V]

If you can find a good welder locally that knows what he is doing the trench can be welded full then deck the top of the cylinder back to the stock dimension. You will not be able to just machine it down without the weld being done first.
Ed

[06roadking]

Thanks, guys I will look for a machine shop and ask if they can shave the cylinder.

Ed, thanks for the advice about welding first. I guess if the machinist doesn't know to do that then I will find another shop.

Panzer,
I am using reverse dome pistons. I will have the heads checked again for warpage before I go to far into the cylinder getting shaved. I may need new heads, but I sure hope not.


Dave

[06roadking]

Took the cylinder to a machine shop that comes highly recommended and they say there is .017" of metal missing. looks like that might be too much to save the cylinder.

What do you think?
What is the best gasket to use when I replace the cylinder and head gaskets?