Ms391 carb adjust

[yetiglide]

My stock carb idles fast now that i put a buckshot muffler on it. My adjustment screws seem to have a grey plug Of some kind in the adjustment holes. How do i remove them and do i need a special tool to adjust or just a small flathead

 

[Leerod83]

Is there not a couple red/orange caps? A picture could possibly help also.

 

[yetiglide]

No red or orange caps like in videos i have watched.

 

[yetiglide]

I think i am 2nd owner of this saw. I bought it a year after we had serious weather causing major tree damage. Lots of people had bought big saws, used them once and they sat

 

[Leerod83]

That looks similar to the red caps that are in most Stihls just gray. It's kinda hard to tell in the pictures. Have you ever removed the limiters on one before? If so I would try that. I use a wood or drywall screw to pull it then trim the tab off it and put it back in. Another idea it the dealer. Check out some limiters or buy a couple so you know what you're dealing with. The IPL for the carb shows what looks like the same limiter that slips over the screws on most Stihls.

 

[yetiglide]

Ok i will show my ignorance. Whats an IPL? No i have never done it before, i am more of a Youtube mechanic. I wasnt impressed with my local Stihl mechanic.

 

[Leerod83]

Illustrated parts list. Shows different assemblies of your saw. Each part is numbered and it corresponds with a list of part numbers. Your dealer has one and you could probably find one here. There's a beg for manuals thread. Check it out. Check out the bottom of this page too.

 

[yetiglide]

Thanks for your help!

 

[atpchas]

yetiglide, check your inbox for 391 IPL and shop manual. Should help answer a few questions.

 

[Bedford T]

From Technical Information 28.2012

2.1.2 Remove limiter caps
The limiter caps must be removed in order to service
the carburetor.
Always fit new limiter caps, as they are damaged
when they are removed!
. Screw the puller 5910 890 4500 (special tool)
counterclockwise (left-hand thread) about 5
turns into the limiter cap
. Align limiter cap – the lug on the limiter cap must
be visible through the slot in the insert in the
carburetor housing
. Remove the limiter cap