Jonsered 670 fuel delivery problem

[romeo]

The compression is right at 100lbs.

thanks

Under a 115 lbs, and I am amazed that you could even get a pop out of it. You can hunt up a piston and clean the cylinder up sometimes. It probably scored the cylinder due to the lean condition caused by the vac leak. The material on the cylinder will be piston material that has transfered to the top of the chrome. I have sanded it out with 400 grit, and put in a new piston and they worked fine. If it worked through the chrome the cylinder is trashed.