Solo 694 compression problem

[Preston Phillips]

My Alpine Magnum stump grinder has a Solo 694 chainsaw power head. Haven't used it for a few years and now I'm 83 and having problem starting it. It does not have a decomp valve and I work out so I ain't that weak but when I pull it on compression stroke it's like it kicks back. I pulled the plug and can spin it easily with no problem. Thinking about putting a decomp valve in the top of the cylinder but it never had one before. Any Ideas?

 

[pioneerguy600]

If it can be done there would be some milling off of cylinder fins, if space allows it would be better to place it above piston travel in the cylinder head. I run a 690 on a mill and it seems to be a mild animal for starting but a very strong running saw.