500magnum

Member
Jul 12, 2016
2
0
Hello I'm new to this forum, I grew up riding bikes and work on them on the side for friends an co-workers. I am currently working on a '81 Yamaha IT175, the owner stated it started to smoke really bad and ran poorly. He parked the bike and it had been sitting for a few years. He happened to find out that I work on bikes and asked if I could get it running again. I had to clean the fuel tank, carb and crankcase out because it drained fuel down into the crank. It started up but smoked really bad and would not run very well. I replaced the crank seals on both sides and this did not make any difference, still smoked very bad and ran poorly. I was using a 40:1 mix of Amsoil Dominator oil. I then pulled the jug off and the piston and rings were due to be replaced so I had it punched the first oversize using a Weisco Pistion and rings. While also doing this I split the case to reseal it making sure I was not getting any oil from the transmission into the crankcase. After all this work it does run better but not great and still smokes to high heaven even with a 40:1 mix. The carburetor has like two main jets, one down in the float bowl and the other one goes outside on top of the carb right behind the slide or after the air filter. I'm really puzzled to why this bike will not run right. I may have left some things out, just ask and I will answer back when I get some time. This should have been a easy job and has turned out to be a real headache. Signed Butch
 

Okiewan

Admin
Dec 31, 1969
29,555
2,237
Texas
I may be wrong, but I thought the older IT's used oil injectors ... ?
 
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