Ok so my neighbor straight-gassed his MS 311. He had a friend (not a professional) put in a new piston & cylinder. I don't know the specifics of exactly what that guy did - whether or not he replaced crank seals, etc. But he couldn't get it to idle after afterwards, even with the LA screw all the way in (which I know is way too much).
I offered to look at it for my neighbor. The saw would fire and rev high for a second and then die. If you tried to give it gas, it would just bog and die. I was thinking fuel delivery problem or air leak, so I started with fuel stuff because that's easier for me... cleaned the carb, looks good. Then I checked the fuel filter and line - filter blows through freely and the line holds vacuum/pressure as best as I can test it with my mouth (I don't have a vacuum tester). So I thought maybe the carb is out of adjustment after the rebuild. I removed the limiter caps and tried richening up the L screw, but without much success. Eventually, I was able to get the saw to accelerate with little bog with the L screw way way out (like 5 or 6+ turns, which is ridiculous) but it still won't idle, and the screw is so far out that it feels loose. I tired a new plug too just for the hell of it.
At this point, I'm thinking that it must be an air leak and the way-out screw adjustment is just barely making it run by compensating for the air issue. But I don't have a vacuum/pressure tester to properly check for air leaks. Before I go that route of buying a vacuum/pressure tester, is there anything else I should check first? Anything I'm missing?
Thanks for the help.
I offered to look at it for my neighbor. The saw would fire and rev high for a second and then die. If you tried to give it gas, it would just bog and die. I was thinking fuel delivery problem or air leak, so I started with fuel stuff because that's easier for me... cleaned the carb, looks good. Then I checked the fuel filter and line - filter blows through freely and the line holds vacuum/pressure as best as I can test it with my mouth (I don't have a vacuum tester). So I thought maybe the carb is out of adjustment after the rebuild. I removed the limiter caps and tried richening up the L screw, but without much success. Eventually, I was able to get the saw to accelerate with little bog with the L screw way way out (like 5 or 6+ turns, which is ridiculous) but it still won't idle, and the screw is so far out that it feels loose. I tired a new plug too just for the hell of it.
At this point, I'm thinking that it must be an air leak and the way-out screw adjustment is just barely making it run by compensating for the air issue. But I don't have a vacuum/pressure tester to properly check for air leaks. Before I go that route of buying a vacuum/pressure tester, is there anything else I should check first? Anything I'm missing?
Thanks for the help.