Dear community, hello from Germany,
I have a problem that has me baffled and I need your advice. One of my first saws was an 1998 Stihl 026 that I purchased used. It was always hard to start. Later on I found out, that the top end was changed to the one of a 024 AV Super and only hat 100PSI compression dry. Anyhow I decided to change the piston and Cylinder to the original spec and did the restoration myself. (I have done lots of 026s) I now have the problem, that the new used OEM top end produces 150 PSI compression, but the impulse still doesn't tickle the carburetor so that it pumps fuel constantly. I did a pressure and a vac test on the seals and they were tight. No leakage whatsoever. Impulse line, fuel line, boot is new. I set the vacuum pump to the Impulse line with the cranklcase under pressure and the needle was hardly moving when I turned the flywheel. What could be the problem?
I checked spark (great); new Bosch Plug, vacuum tested the carb (tight) , put the carb in a different saw and that one ran like a dream. I even put shopair carefully into the crankcase via the impulse line to check if there ist blockage. Nada. Put some droplets into the cylinder, saw fires up and dies immediately.
What have I missed? The seals are still old ones but they test out good. Whole saw holds pressure and vacuum. Please help me.
I have a problem that has me baffled and I need your advice. One of my first saws was an 1998 Stihl 026 that I purchased used. It was always hard to start. Later on I found out, that the top end was changed to the one of a 024 AV Super and only hat 100PSI compression dry. Anyhow I decided to change the piston and Cylinder to the original spec and did the restoration myself. (I have done lots of 026s) I now have the problem, that the new used OEM top end produces 150 PSI compression, but the impulse still doesn't tickle the carburetor so that it pumps fuel constantly. I did a pressure and a vac test on the seals and they were tight. No leakage whatsoever. Impulse line, fuel line, boot is new. I set the vacuum pump to the Impulse line with the cranklcase under pressure and the needle was hardly moving when I turned the flywheel. What could be the problem?
I checked spark (great); new Bosch Plug, vacuum tested the carb (tight) , put the carb in a different saw and that one ran like a dream. I even put shopair carefully into the crankcase via the impulse line to check if there ist blockage. Nada. Put some droplets into the cylinder, saw fires up and dies immediately.
What have I missed? The seals are still old ones but they test out good. Whole saw holds pressure and vacuum. Please help me.