Stihl 021 idle adjustment

Well stihl doesn't make carbs. It's mostlikely Walbro carb.

 

Haha good to know.

 

Believe it its truth

 

Or OEM zama like this in the picture

OEM STIHL Carburetor Carb Fits MS170 MS180 017 018 ZAMA 1130 120 0603 Chainsaw

 

Excuse my ignorance guys but I only see 2 adjustment screws on my 021. Is this correct? How do you go about tuning this saw with just 2 screws? Thanks.

 

Should have 3? I don't think that carb was one without an H screw like the 170/180?

Pull all the covers off and look and if you still can't see it post a pic.

 

Manual doesn't show an H adjustment
https://www.stihlusa.com/WebContent...-MS-021-023-025-Owners-Instruction-Manual.pdf

 

The AfterMarket Walbro WT 286 clones have the H screw. Eg:
Carburetor Carb For STIHL Chainsaw 021 023 025 MS210 MS230 Walbro WT 286 Zama
I've used quite a few of these with good results. You can JB Weld the impulse hole at 2 o'clock and drill out the plug that's at 12 o'c. Many more saws have a 12 o'c impulse hole.

 

When the cover is removed there are 3 screws

 

I will post a pic when I get home but the cover only shows 2 holes: L screw and LA screw.

 

They must not want you messing with H so they didn't put a hole in cover.

I have found that if you can find a china replacement carb on ebay they usually all are adjustable where the originals werent

 

Pics

 

So once the cover is off can you get your screwdriver on a screw head to turn or is there a blank there like someone was talking about?

 

it seems like that top left hole is the H adjustment. I can fit a small screwdriver in there. It feels like you can turn it in and out.

 

Well if you can then there is a jet there I would assume? Is there a rubber boot behind the plastic flange between it and the carb? If you can pull that off you can see if there is a screw or shine a bright light into the hole. Or blow out the hole with air and clean it up good and try to back the screw out all the way and pull it out.

Or just take two minutes and pull the carb off.

 

Well I was able to adjust the H screw. I think I was able to adjust it correctly. I feel the saw was running lean before I adjusted it. My biggest fear with tuning saws is having them run too lean then burning the cylinder up. Any suggestions?

 

Have it make that distinct four stroking sound when you hold it wide open out of the wood. Then clean up when pit into the wood. Too lean the saw will sound like a crotch rocket motor cycle when you do this. And too rich it will run really slow and sound like crap.

 

Pretty sure I got it right in the middle.

 

As long as it four strokes after it revs all the way up when holding it wide open its right and you won't burn up the cylinder from that.

 

Looks like the shop that worked on it already elongated the hole after they put the new carb on, or did you do that "