Stihl 031AV carb adjustment confusion

[Tomas Caballero]

I am confused. The service manual for Stihl 031 diagram shows the H and L and Idle as follows which doesn't make sense. My common sense tells me in the diagram the H screw should be #3 and closest to air filter, the L screw should be #1 and closest to engine, and the idle screw is #2 the knurled thumb screw below the two needles. Or I s the diagram correct? What's the setting for the knurled thumb screw? I forgot, the carb is the Tillotson HU model. Thx. Tom

 

[DND 9000]

As I see, this picture in the owners manual is wrong. I see it the same as you. 1 is the L screw, 2 is the LA screw and 3 is the H screw.

 

[Boudreaux In Eunice La.]

My stihl weed eaters are Low side closest to filter and Hi closest to the engine. I don't own a stihl chainsaw Just Huskys and a Mcculloch.

I would bet a round nickle that your saw is the same as the weed wackers ~!~!

 

[DND 9000]

Well it could be that the carb is mounted upside down. That would change the positions of the adjusting screws, but I don`t know if this is the case on the 031.

 

[HarleyT]

That manual is simply incorrect.

 

[Tomas Caballero]

As I see, this picture in the owners manual is wrong. I see it the same as you. 1 is the L screw, 2 is the LA screw and 3 is the H screw.

I checked the 031 IPL and it lists #2 as the idle screw, #1 as L and #3 as H so either the manual is wrong or the IPL. The function of the knurled thumb screw as the L screw just doesn't compute. It has to be the LA/idle screw. So what's the factory setting of the knurled thumb screw so I can then fine tune? Thanks.

 

[HarleyT]

You set it while running, it has no "pre-set". On the other 2 screws, the L is closest to the engine.

 

[Snowchaser]

Checked mine. H is closest to the filter. All 3 of mine have h and l cast into the carb.

 

[atpchas]

From the 031, 032 shop manual

 

[Tomas Caballero]

Thanks all for the responses. atpchas picture is how it should be. Funky 031 manual on the internet got me all messed up but the responses and playing around with it got me all square. This saw is headed to Canada for firewood duty and it purrs like a kitten.