Chainsaw Repair

The closed port cylinder I used on this chainsaw came from a Brison 6.4 opposed twin model airplane engine. It is 104cc. The engine had been run on Amsoil oil at 100 to one. The right cylinder looked as though it had been straight gassed. I got it cheep and the guy told me he had put a new cylinder and piston on the right side. After pulling that cylinder, it appears that the new cylinder was only new to him as it had been used quiet a bit. It may have originally come from a single 3.2cc Brison?

There were several companies that made Sachs Dolmar based model airplane engines of all sizes back in the late 80's up through about 2005. They used the Dolmar cylinder and piston assemblies. These model airplane engines were all different combinations of cut down Dolmar cranks and cases to custom bottom ends.

I also have a never run Brison 3.2 single cylinder model airplane engine from 2005. The 3.2 single from Brison was probably the most popular of these.