[brown986]

Kainam, this is anecdotal. I have stopped by my mechanic's shop twice recently & both times they were putting big bore S&S jugs, etc. on 2 fairly new M8 motors w/less than 5,000 miles. In both motors, they found scoring on both pistons & excessive carbon build up on valves & tops of pistons. Owners had no idea anything bad was going on, just wanted bigger S&S jugs.

Edit: scoring on both cylinder walls, not pistons. My bad.

 

[brown986]

Pics from second motor:

View attachment 796398

View attachment 796399

View attachment 796400

View attachment 796401

View attachment 796402

View attachment 796403

Kainam, wondering what your original, corresponding pistons, cylinder walls, etc. look like & after how many miles . . .

 

[brown986]

MoCo refuses to send a crate motor as that is not what was installed initially despite all the part numbers being identical to the kit + short block.

Numbers no longer match as the last motor was built on a replacement short block.

Only way to get a numbers matching bike now is to lemon law it and start over.

I don't believe that would be worthwhile or really that productive.