MS210 wont stay running

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GH Sawguy

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I purchased a well used Stihl MS210 locally that i thought id breathe new life into. So i bought a carb, fuel line and other parts from amazon. Usually that does the trick. It still didnt want to stay running when under full throttle. I took the muffler off to inspect. Thought the screen might be clogged. There wasnt one present. I opened the fins a little, they looked flattened somewhat. I also drilled out the hole a bit inside the muffler. It now starts on about the 6th pull (sucks) and dies just after i throttle up. I ass ume its a carb adjustment issue??? Any help is much appreciated.

Go Ducks!
 
...oh also my reasoning for opening up the muffler was that when i removed muffler i started it. I gave it full throttle several times and it DIDNT die so i figured it was a little choked.
 
Carb or air leak as long as piston and ring look alright... IMO.
Turn the H and L jets all the way in. Then turn each out 1.5 turns. I believe that's the manufacturer baseline. Adjust from there. I adjust the H first, then tweak the L... But to each their own. Then I fine tune it in some wood. Make sure it's good fresh gas, and clean air filter. If you can't get it, re-clean the carb. Pull jets, and spay everything really well with carb cleaner. Then start over.
If that still isn't working, compression, then pressure and vacuum test.
That'd be my angle of attack.
 
My Jred was doing the same thing once. I put a carb kit, and thought I had cleaned it really well. I'd tune it nice, put it away overnight, then it would "lose" its tune. That went on for awhile, tuning everyday. Sometimes it'd be too lean, sometimes too rich.
I decided to pressure/ vac test it. For giggles, I pulled carb apart and stored everything in carb cleaner while I tested for an air leak... which it passed.
Next morning I reassembled it, and it was fine and has been ever since. I'm guessing some gunk got stuck into one of the jets. Soaking it had freed the gunk and cured my woes.
Just an FYI.
 
Vac and pressure test it.... I know, easier said than done.
It could be as easy as a bad fuel or impulse line.
If it starts reliably around 6 pulls, then pull it 5 times, quickly crack and seal the fuel tank, then keep pulling....
Easiest way to check tank vent, though I doubt that's the issue.
 
Ok....so i reset the hi and lo and started with 1.5 turns each. I can get it running pretty well at closer to 2.5 on the hi and 2 on the lo. I guess the extra turns to compensate for the muffler modification. The only issue now is its spongy right when i hit the throttle. I feather it a little and it rocks. How do i get rid of the initial spongy throttle response?
 
Lean the low (turn the L in) until it's snappy. Don't worry too much about the chain turning at idle. It's a balance. Get it close as you can so that it revs nicely and chain doesn't move very much.
Mess with the idle adjustment until the chain just barely stops moving.
Once you there, with it idling tip and roll the saw all around, pausing on each side.
Listen for any changes in idle rpm. If you hear one, your L is too rich.
 
I check the H adjustment by warming the saw up, then making some cuts. Making the saw really work in the cut. Then immediately pull saw out of wood and hold throttle wide open. You should hear it four-stroke at max rpm.
 
Ok...i started over. About 3 turns out on low has decent snappiness. Not sure about high yet. When i throttle up it sounds good. When i let off it stalls. Is that as simple as another 1/2 turn out on idle, or? I see people talking about hi and lo all the time but rarely the setting for the idle screw
 
Set the idle screw somewhere around 2-3 turns out from bottomed out..doesnt really matter until you get the L/H needles in the ballpark. For tuning purposes you just want the throttle blade a tickle open when the throttle blade isnt engaged by the high idle/"1/2 choke" position.

Set the L needle 1 turn out on the low and H 1.5 turns out. And then try to start it. When youre in the half choke/high idle position and it fires up, dont touch the trigger. Does it stay running or die?
If it does high idle and you touch the throttle off high idle, does it idle or die?
Can you feather the throttle to get it to WOT?

If it doesnt run in high idle or idle but can get to WOT or idles but no WOT and doesnt react to any needle adjustments +/- 1/4 turn then something is mechanically wrong that needs to be diag'd.
 
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