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View Full Version : 125 Tri Moto Piston help?



13ogart
11-15-2016, 06:27 PM
I don't post much on 3wheelerworld any questions i have usually i can find the answer but i need some help.

Recently i purchased a 1981 125 Yamaha Tri moto in really good shape it was sitting for years. It ran but barley so i did some investigating and
ended up replacing both crank seals which were in really rough shape. While doing all this i got a little careless and forceful and actually broke the what i believe to be stock piston 56.00mm if i am correct. Im searching for a piston but am having a rough time, my local Yamaha dealer could get me a wiseco piston first over size for $170 plus $65 to bore the cylinder out (Canadian price). I thought those prices were kind of bizarre specially since i only paid $200 for the 3 wheeler. i have been researching most online resources trying to find a standard size piston that ships to Canada and wont cost me a arm and leg. Ive also looked into using a DT piston? im just not sure if they will match up the cylinder is in good shape it shouldn't need to be bored out. If anyone has some info that will help me out or even links to certain piston that will work please let me know thanks.

236983

350for350
11-16-2016, 10:12 PM
I don't have any sources of pistons. First off since you're into it that far, I'd recommend boring your cylinder. It may "look" good, but could have wear that you can't see, only measure. The price of the wiseco from your dealer doesn't sound too bad, and the price of the bore sounds pretty good too. You can do what you want, but I look at it like this. You can go as cheap as possible, but how long will it last? At least if you go to an oversized piston, you know that you will be starting over fresh with zero wear.

13ogart
11-17-2016, 05:53 PM
Thanks for the advice, i guess your right i should just order a oversized piston and get it bored out it seems like it would be easier rather then order a 56mm then have to get bored out and find a new piston. I was just trying to find something quick and easy! But i guess you gotta pay to play! Thanks