Actually he 76 or 77 SST sled itself makes a great oval sled. It was fairly light with a great highly adjustable ssupension, good rubber track for studding, and robust drivetrain.
But the fan-cooled motor limits it's power. It competed pretty well in Stock E. (the lowest stock class in competition) against other 440 fan-cooled engines like the Enticer and Jag.
Here's a link to a thread where you can see me competing with a 77 STT 440 FC in 1978 or 79. I won some prize money with it here and there, but I did a lot better with the 75s!
http://www.snowandmud.com/forum/390/1981-yamaha-enticer-340-a-22729-4.html#post1310109
WOT
But the fan-cooled motor limits it's power. It competed pretty well in Stock E. (the lowest stock class in competition) against other 440 fan-cooled engines like the Enticer and Jag.
Here's a link to a thread where you can see me competing with a 77 STT 440 FC in 1978 or 79. I won some prize money with it here and there, but I did a lot better with the 75s!
http://www.snowandmud.com/forum/390/1981-yamaha-enticer-340-a-22729-4.html#post1310109
WOT