MS390 hard to start when cold

[Rod Dog]

I'm new to this site but i've been running stihl saws for years and this is the first one I've ever had a problem with starting. This saw is only 2 years old.

I have a MS390 that is a real PITA to start when it's cold. Seams like it's not getting enough fuel. I know the EPA has leaned the new saws out to comply with emissions standards. Is there any way to fatten this thing up so it will start when it's cold.

My starting procedure.
Full choke till the saw pops. Usually 2-3 pulls in real cold weather 10-15 pulls ish.
Then full throttle lock. Saw will pop and sputter and die When it's real cold this can take a looooooooot of pulls
Then normal run position. Saw starts and dies it will do this 5-10 times before it will run long enough to get my finger on the throttle to baby it along enough take any more that a little bit of throttle.

Does the same thing when i run it out of fuel. Just not as bad. But then it's warm it will start with a 1/4 pull just about every time.

Also seams to run warmer that it should in hot weather. (LEAN?)

any suggestions would be appreciated. Also Upgrading to a Pro saw is not in the budget.

Thanks in advance

 

[Saw Dr.]

Check your fuel line first, and also your tank vent. The fuel line will crack just above the grommet where it comes out of the tank. If it is cracked (likely) then you'll want to clean out the carb just to be safe. You can also turn the "L" screw counterclockwise to richen it up a bit.

 

[SkilsawGuy]

I have a MS390 that is a real PITA to start when it's cold.

The old boy down the road gave me a pretty good tip when he noticed that
my right arm was 2" longer from pulling my MS310 one day.

His saw is the MS390 as well and all he does is keep a spray bottle handy
with the proper fuel mix and pulls off the orange cover, gives it two or three
shots of fuel mix and puts the cover back on and away she goes.
His neighbor told him about this because he owns a MS390 as well.

I tried this method with my MS310 and sure enough it really saves you arm.
Once its all warmed up and stuff it always starts with one pull.

Mine sat in the case in the garage for 6 months or so with fresh fuel mix
and stabilizer, and I used the spray bottle trick to fire it up just because.

Just my findings, Ray

 

[blsnelling]

If you have to prime your saw, then something's wrong with the it, likely just a carb adjustment. Check to make sure your choke is closing all the way as well.