While gathering parts to rebuild my '86 XR600R, I picked up a new old stock OEM piston and ring set from eBay. They were still in the Honda boxes with the part numbers on them. The number match the parts fiche for my bike. My engine had a Wiseco piston in it. When I started putting things back together with the new parts, I found that the wrist pin was too short for the piston. I thought that the Wiseco pin was simply shorter for their pistons, it's clear that the bottom of their piston is narrower where the pin fits. A member from here has put a stock pin in the mail for me so I'll have the right one to put it back together. However, while searching around looking at parts etc., I see that Wiseco claims their wrist pins will fit their pistons as well as the OEM Honda piston. They say it should be 2.5" long, which the pin I have is. So I started looking a little closer, and my Honda piston looks a little different than the two I can find pictures of online. Notable, the bottom of the skirt on mine is flat, while there are angles cut in the ones online. The bottom of the piston on the sides below the pin is also shaped a little different. They both also look narrower where the pin fits than mine. My piston fits a stock bore cylinder perfectly, I know it's the right 97mm bore. I put it on the rod with the short pin I have, and the skirt does not hit the crank, it will fit fine if I can get the right pin. I'm kinda worried that the pin that's in the mail will be the same length as the Wiseco pin I have. If so that's gonna suck! Here's a few pictures of my stock piston, as well as the two I found online of other stock pistons to compare. The last one of my piston shows just how short the in is, it's slipped all the way against the clip on the other end. Can someone identify this piston, or verify that the OEM pin is longer than the Wiseco pin, same length? If I had known I'd run into this problem I would have bought a stock size Wiseco piston to go back in. I should have known better than the rush it and try to save some cash... Oh well... These are pictures of the OEM piston I have, part number 13101-MK2-043 See how the wrist pin is too short? These are picture of other OEM pistons I found online. Note how the skirt is different than mine, and they look narrower where the pin fits. Any ideas?