Stihl 038 mag 2

[Connor99]

Hey guys I'm new here but am hoping to get some answers about a problem I have been having. I have a Stihl 038 mag 2 that has been my runner for years and never given me a problem up until now. The problem that I am having is when the saw gets hot it will not idle and will bog pretty bad when I apply throttle to keep it from stalling out. The say only does this when it gets hot the problem doesn't occur when it's warming up and it usually works good cutting for at least the first 10 minutes. Also the saw runs excellent wide open so I've been a little nervous about working on it and screwing something else up. Any help would be appreciated.

 

[HarleyT]

Don't keep trying to use it until you find the problem.

First thing to do is correctly go through the fuel system.

 

[nstueve]

First we need more diagnostics to figure out a problem like this or we are all just guessing. Do the top 3 things.

1. Compression check with visual piston inspection for scoring. 130psi+ needed for good running.

2. Vac and pressure test the saws crankcase and top end.

These two rule out most mechanical problems for the most part.

If these are good you're usually looking at spark and fuel problems.

3. Carb kit and fuel lines with new fuel filter and fresh non-ethanol gas mix. $20 to do these and good routine maintenance with a saw of that age anyhow. I suggest guys get a can of true fuel or similar to rule out bad pump gas too. Set carb to 1 full turn out after lightly seated on both high and low fuel circuits. Marked H and L on carb cover and carb (maybe try setting carb to stock settings first b/c it's easy and free). OE carb settings on 1:1 turns out should run most any saw decently with fine tuning from there. OEM fuel lines recommended unless regular rubber fuel line or tygon works.

If all of this doesn't solve your problem it could be anything from a plugged up carb, to coil going bad, to ??? Either way do some more diagnostics and check back in with us.

 

[alexcagle]

Due to the age of the saw; don't forget to take the air filter off, let the saw warm up, and while accelerating, see if fuel sprays out of the carburetor, which would indicate a worn piston intake skirt.