TONUP
New member
Hi guys. I need some help. I have a 1997 yamaha sx 700 that I had just picked up 2 weeks ago. I took it out for the first time today and within 10 minutes it seized the center piston on a high speed run. It looks like it got leaned out which is my fault because I did not properly clean the carbs ( it sat in a shed for a couple of years). I know the previous owner well and talked with him today about were to get parts. Here is my problem. He seems to think the engine has a stroker kit in it installed by the first owner who is not avaliable to answer my questions. The cylinder jugs have a one piece spacer (6.5mm) between them and the block. The cylinder bore is 73mm as far as I can tell and I think stock bore is 70.5mm. The pistons have a distance of 36 mm from the center of the pin to the top of the skirt. Inside the piston, there are some markings ( 9g9, LP, ART,an arrow and something that looks like a upside down T with the number 1 below it). No other markings anywhere. If anyone has an idea, info on stroker kits or has a stock piston they can look at to confirm what I am seeing as far as markings, I would really appreciate it. Thanks.
I have the same sled that I just popped the stator side piston (looks like a piece of metal got in there somehow) and the markings of the factory piston are 8CH00. ART and there is also an S (standard I think) and also the T with the number 1 below it Hope this helps.
TONUP
New member
Thanks for hte reply.