1969 yamaha endro mix and match

[hellbound547]

so one day i was riding my blaster and the motor seized up. so me and my buddy took the head and cylinder off and the ring hooked up in the exuast port, and i needed a way to get home. the piston and rings were shot and the cylinder was untouched luckly, then my buddy had a 1968-69 yamaha endro 175 motor in his basement. he said the motors looks alot alike so he wwent and got the piston and rings and compared them. they were exacly the same. so we roughed over the cylinder wall with some 600 sandpaper, and threw it all back together. this happened all with in an hour lol. fifth kick she fired right up. and we checked the compression and it was 145 psi. this was about 3 and a half months ago. i have been runin it HARD ever since with out trouble, i noticed a slight increase of power. any one try this befrore?

 

[hickskateboarder]

i would have to say your probably the first. i'm just curious what you measured the piston with. i guess if your compression is 145 it must be the right size, and if the piston was too small it probably would've broken by now. did you also measure the distance from the pin to the top of the piston or did you just throw it in and try it? that would've sucked if it was bigger with the enduro piston if you kicked it real hard the first time...

your probably gonna get yelled at by a lot of people, but i give props for trying something different and being creative.

 

[xjma]

That's pretty surprising. Not so much the fact that the piston was the same bore, but that the holes in the skirt lined up alright!!

Also surprising that you have no leaks without using a new head gasket!!

 

[hellbound547]

all my buddy did was take the old piston and the new one and compair them by eye and everything was identical i could have taken the micrometer to it and i know they would have micked out the same... yah i was expecting to have a leak in the head gasket or the base gasket but suprisingly i never even had a little one thats not too bad for throwing the old gasket back on... just to add a nothe the wrist pins were also identical but the enduro wrist pin berring had a smaller od then the blaster by about 2-3mm the id was obviousley the same because the wrist pis was the same...

 

[Lindso]

If I had to venture a guess, I'd say not many people have a motorcycle engine from '69 sitting around..

 

[hellbound547]

no probaly not lol....i was just wondering.