i halve a brand new stihl ms 391 chain saw that will cut just fine till you shut the saw off to fuel it up. once you stop it it floods and will not start for a few hrs. it floods so bad that i took the carb off and puled on the pule start and it fired right up. i have stoped using it half way threw a tank of gas and opened the tank and the fuel was boiling. i cant figure what would cause this on a brand new saw.
#2
primerbulb120
If it's brand new it should still be under warranty and you can bring it in to the dealer for repairs.
yah i have had it in 4 different times and they told me there was nothing ring with it every time. the problem is they are just starting it up and not actually working the saw to get it to do what it is doing. i am sick of taking it to some one that has no clue what they are doing. when you get the saw cutting is when the problem occurs.
#4
primerbulb120
Maybe try contacting the manufacturer directly instead of going through a dealer?
What is happening is the fuel tank is pressureising.
This pressure exceede the pop off pressure ( about 10 psi) of the fuel valve which opens up thus allowing fuel to pour through the carb & flood the engine.
User "fix" will be to udo the fuel cap & let the pressure out as soon as you stop.
Don't know if you tank valve is one way or two way
Another thing you want to check is the "shutter" that controls the air flow to the carburetor. This shutter is located between the carb and the cylinder, on the RH side...looking at the saw from the handle end....with the top cover removed. In the owners manual, there is a setting for this shutter, depending upon the temperature you are using the saw in. If you have the shutter set for Winter operation, on a hot summer day, for example, you might be causing the saw to overheat. I have an MS 391, and the setting of this shutter definitely affects the saws operation. Mine runs just fine for extended periods of use, but can be a bear to start initially after sitting for several days/weeks.
