Does anyone know how to tell the difference between a quadra 75 and a quadra 100? I recently purchased an engine which the owner speculated that it was a quadra 75, but I believe it may be the 100.
Thanks, Mike

A 75 will be made with a cast aluminum case, round on the back, with 4 1/4x20 tapped holes in a small bolt pattern..
A 100 will have a machined case...The 100 engines usually had a compression release in the cylinder at the top....

It has the compression relief, but I will have to check the rest tomorrow when I get off of night shift. Thanks for your help.
Mike

Ya got it off ebay dident ya!!!! Had to bid against me
Pat