I fly a Black Devil Paralite machine.
I have thought for some time how I could check if my reduction pulleys are perfectly aligned.
Since the perfect straight line would be a laser beam, I tried to incorporate this concept.
I used a laser level and by shining the straight line along the grooves of the large pulley I could easily see when the grooves lined up with the lower pulley.
Attached are the pictures I took when I aligned the pulleys. I have yet to run the motor for an extended period of time to see if it helped.
Note that the center bolt on the large pulley have to be tightened as it is needed to see where the grooves line up during actual running conditions.
The picture below shows a slight missalignment.
I bought a shim from a local hardware store and added it between the large pulley shaft and the engine block.
I also added a picture of the exhaust where I added a piece of rubber hose (radiator hose) between the exhaust and the muffler as it appeared that they were rubbing against each other.
Ola Wesstrom -Indianapolis