Yamaha GP1300R engine rebuild

[JakeDale]

I'm doing a rebuild of my GP from 2004 due to piston failure in two cylinders. Both cylinders are sent away for welding and new nikasil but i'm hesitating about the cylinder head. Both domes are more or less okay but the part between the dome and the cylinder wall is not.

Replace, grind the ridges off or do nothing?

[JakeDale]

Someone must have encountered this before?

[Wild Thing]

Source a replacement

[Myself]

Get a good used one, or have a machinist fix that one.

[JakeDale]

Thanks, i thought so. Seen a lot of these att ebay with the same kind of damage and was hoping to avoid replacing.

[JakeDale]

I'm bringing this thread to life again; no luck in getting a used good one so i did some grinding one this one. Do you think it would work or is it going to melt or create detonation?

[Myself]

Surely there is a machine shop near you.... it will run like that, but not at it's best. Send me the head and $100 and I'll mill it and send it back.

[Myself]

Here's a Kawasaki 650 head I did recently

[JakeDale]

This pwc project is killing me. Left the head to a shop and they messed it up. Anyone having a head for sale?

[Myself]

What did they mess up?

[Jonesyfxr]

Check Ebay

[JakeDale]

One shop did the welding and the weld did not fully cover the edge and they did not clean nor grind the surface leaving the weld with poors. Next shop did the milling in a cnc machine. But they missed out center leaving the edge of center compared to domes. I picked up the head for final edge trimming when i realized the combustion chamber edge is offset.

[Myself]

WOW! The $100 I quoted you sounds real cheap now......you would have been ready to go LOL!

Incompetence is rampant these days.

[JakeDale]

Yes, i know and now there is a bigger problem then it used to be. I guess it's still possible to weld it again and then put it up in the lathe to get the combustion chamber right but then it needs resurface and i wonder if there is enough material left.

[Myself]

At this point I believe I would scrap that thing and count it as lesson learned . Buy a good used head and move on.