Debra
04-27-2007, 05:06 PM
I dismantled and cleaned an O.S. 80 2cycle engine with a rear induction rotary valve. When I reassembled it, I noticed 2 notches on the valve, one of them marked with an R . I don't know which one to use. Is it possible to run the engine "backwards"?
Thanks for your help.
Dear Mr. T,
That O.S. 80 2-stroke you have is a real oldie. Unfortunately, I do not have one to check. However, anytime a rear induction engines has two slots or holes to drive the rotary valve, one is for reverse rotation. I think it is safe to assume that the slot with the R is for reverse rotation. An easy way to check for correct timing is to rotate the crankshaft 30 - 40 degrees past bottom center in the direction of normal rotation. The rotary valve should just be starting to open.
Regards,
Clarence Lee
Thanks for your help.
Dear Mr. T,
That O.S. 80 2-stroke you have is a real oldie. Unfortunately, I do not have one to check. However, anytime a rear induction engines has two slots or holes to drive the rotary valve, one is for reverse rotation. I think it is safe to assume that the slot with the R is for reverse rotation. An easy way to check for correct timing is to rotate the crankshaft 30 - 40 degrees past bottom center in the direction of normal rotation. The rotary valve should just be starting to open.
Regards,
Clarence Lee