Mercury outboard Yamaha 20HP piston 67mm 2.638 6786M Start Price USD 19.99 Current Price USD 19.99 Time Left - Bid Count 0 Buy It Now Price - Reserve Price - Start Time Thursday, May 15, 2008 End Time Thursday, May 22, 2008 Location Seattle See more about 'Mercury outboard Yamaha 20HP piston 67mm 2.638 6786M' Description         One NOS vintage Mercury outboard Yamaha piston 67mm ( 2.638" ) Quicksilver part number 761-6786M, Yamaha made. There have been 2 labels: Under the factory Quicksilver label is another older label that says Mariner Parts and Accessories #656-11631-60-98 which appears to be the Omax part referenced here: http://omax-marine.com/e/pro/piston.html  YAMAHA Outboards 656-11631-60 20/25HP 32.5+4.3 72.3 which gives the exact matching distance between rings and then distance down to the cutout and overall height. These pistons (all are same size) are cast with the name YAMAHA inside the piston head and "IZUMI" This is a bare piston with no rings or wrist pin. I dont know what Merc motor models this fits, except that it is before 1972. It would be single piston to about 10 hp (the 9.8 perhaps) or 2 piston about 20 hp. Takes 18mm dia wrist pin- should be no more than 2.47" long. (Wiseco S-278) Two rings top groove for a .069 ring bottom oil groove measures .072 with my guages The top ring area of this piston is 1mm smaller than the body. (tapered) Its side contacting edge is 2 11/16" high or about 68mm overall height is 72mm. distance from the top of the wrist pin opening to the side top of the piston measurement is 913 thousands, .913", the piston is dome top shaped, so that is only to the edge corner. It seems to match these dimensions: YAMAHA PISTON & RING APPLICATIONS HP       Years      Cyl.     Bore Size         Piston                OEM #                     Rings                   OEM #         20    1996-97      2      2.638" Std      9-53800     6L2-11631-00-97      9-54800        6L2-11610-00- Reference: http://www.mallory-marine.com/pdf/OEM_Mallory_Competitor_Interchange.pdf This piston seems also to be similar to ZX6R Ninja 95 to 99 but I don't know the pin size for that one..  Please look at the picture and ck your measurements, this is all I know about this part. ********************************************************************************************** High bidder to please add for insured US Shipping:  $5.00. No Paypal to foreign countries IMO or Canadian/US currency.      No returns or exchanges, please. Place a Bid!