Chainsaw Repair

Posted over @ EHP also.  Finally got to the 665 had the 7900 P&C kits since Jan.  Pulled the cyl.  Much to my suprise the Mahle ID # was 52ZK13W2 w/windowed piston.  I thought cool somebody has allready upgraded it to 681 52mm.  However, it is 47mm.  Quad port transfers.  It looks like they used the same cylinder blank and bored it for 47mm(665) instead of 50mm(675) 52mm(681).  The differences in the cyls 665 and the Dolmar 7900 that I could see was the Solo cyl has external raised tunnel on the rear transfer.  Transfers appear to be identical in size.  Upper transfers are smaller and placed closer to the intake port.  Top mounted decomp valve.  The extra 5 mm material in the 665 cyl makes it noticeably heavier. 
Shep

I think Shep meant this was a CP cylinder.