well im new here,so add some lube ok.
ive been reading this post,waiting for Jeff to post some more info about pistons.
i own a TY350 that needed a new piston.weeellll it still needs a new piston.
ok,here is my story,it might be a bit long,so grab a drink and read on.
i bought a 1985 TY350 in november,got a real good deal on it.the kid said it ran out of power and popped in front of his house one day.
ok,im somewhat mecanicaly inclined,ive been around motorcycles a bit,dirt and road,2 and 4 strokes.looking for a winter project that isnt a bicycle,plus ive been looking for trials bike for a while.yes,this one cought my fancy for some reason.
so i get it home,do a quick once over.ever thing checks out,but the fuel is on,no gas in tank.i put fuel in tank,kick it three times,she runs,she run pretty good.come may i go to trails event.10 sections three rounds.i do 9 sections.
no more.bike is making a nasty pinging noise.i park it,b.s,drink beer and watch others have fun.get home and find a broken piston,or the holes in the piston got real big.
my search started.months later,looking everywhere,local bike shops,the net,i find a RT-1 piston at the local yamaha shop.that is after i cant find a TY350 piston ANY WHERE.
it is standard bore,it fits like it should.i have the holes drilled in it,then i find out the skirt DOES need shaved.all the work is done by the local yamaha shop.
i put it in,check for clearence.it looks good.
i fire it up,warm it up,shut it off for it can cool down.start it back up.sounding and running good.decide to check my clutch adjustment,3rd time i let my clutch out hard a nasty sounding pinging sound comes from the motor.
Grandson who is 7 ask how did a rock get inside the motor papa.
yep,the piston broke again,or the holes got real big again.
but i found a spec that shows the holes should be 10mm above the skirt.yes,it was after i got the bike back together.no,i dont know if there was a 10mm space or not.i just know my piston broke.i cant go riding with my Grandson tommrow.
but i will be looking for another 360 piston,probly a R-2.OR WHAT EVER I CAN FIND.
a RT-1 piston will fit.YOU have too have the HOLES DRILLED,SHAVE the SKIRT.but remeber,the holes have to be 10mmabove the bottom of the skirt.at least thats what the spec i seen showed.
i told you it was going to be long,i just hope i didnt bore you to much.im just bummed about not getting to ride with the grandson,he was looking forward to it.but not as much as i was.
oh,try this at your own risk and expence.