# Stihl MS 210C carb adjustment



## Rick A (Jan 14, 2009)

Does anyone have any expertise in adjusting this carb? According to Stihl it doesn't need mixture and idle adjustment, but it seems to run too rich and won't idle. We've put a kit in the carb, cleaned the air filter and exhaust screen. It'll run fine for awhile then won't start. Any thoughts greatly appreciated.

Rick A


----------



## geogrubb (Jul 28, 2006)

What carb does it have? Most Stihl products use several different carbs, mostly Zama, post the info from the carb and someone will help. Have a good one. Geo


----------



## Rick A (Jan 14, 2009)

I guess that'd help. It's a Zama C1Q. The other #'s on it are S90A and 611A.
Thank you, Geo.

Rick A


----------



## geogrubb (Jul 28, 2006)

Rick A said:


> I guess that'd help. It's a Zama C1Q. The other #'s on it are S90A and 611A.
> Thank you, Geo.
> 
> Rick A


Go to www.zamacarb.com then select the Service/Aftermarket tab there is great info for your carb there. My normal suggestions are if you put a kit in the carb use the old metering arm unless the old one was very worn as it has the proper height setting. Also if you have it running, spray/dribble carb/brake parts cleaner behind the carb and along all mating surfaces to see if the engine tempo changes, if it does you have an air leak. Have a good one. Geo


----------



## Rick A (Jan 14, 2009)

Thanks again, Geo; the Zama site is informative enough to provide me a good chance of solving my problem. If not, I'll be back!

Rick A


----------



## Rick A (Jan 14, 2009)

*Still struggling*

I've studied the Zama info and checked one or two things they suggested, but no help. I leaned the idle mixture and checked the needle-lifting arm in the carb, but it still loads up with gas. Any more suggstions? Thank you.

Rick A


----------



## glenjudy (Aug 26, 2006)

Define "loads up with gas".........
like, is sparkplug drenched in fuel when it dies ??
Does it smoke when it's running ??
fuel coming out the muffler, etc. ??
Does it have both L and H needles that are adjustable ?? 1 1/4 turns out should get it started....
Does plug have spark after it dies ??

etc.


----------



## Rick A (Jan 14, 2009)

I don't use it (belongs to a friend), but he says it'll quit while idling and not rev up. When he's brought it to me and I've pulled the plug, it's been wet. It seems to smoke more than it should, not wet around the muffler. I leaned out the low speed mixture some. When I start it from cold I have to leave the choke open and hold the throttle open. I haven't checked for spark after it died because when I've run it for a few minutes, it didn't die like he describes. I may have to go to his place and cut with it for awhile to experience what he describes.

Rick A


----------



## Rick A (Jan 14, 2009)

Still struggling. replaced the plug, it ran fine for awhile half hour or so then wouldn't start. Lot of smoke coming from the exhaust. Any further suggestions would be appreciated.

Rick A.


----------



## justin3 (Apr 10, 2007)

It sounds almost like a restricted exhaust, I just did one last night on a stihl br400 blower, gotta take the muffler off and heat it up with a torch. This will burn off any carbon deposits built up blocking passageways. Be prepared for alot of smoke. If the blower continues to run rich you may need to bend the arm in the carburator downward just a little to reduce the amount of fuel entering.


----------



## Rick A (Jan 14, 2009)

I took the muffler off earlier and it didn't look at all restricted, but I'm not an expert. My understanding is that the float arm is supposed to be positioned so that it is just below a straight edge laid across the face of the carb body. I think I have it right, but worth checking again. Thank you, Justin3.

Rick A


----------



## paulr44 (Oct 14, 2008)

There is no published carb. adjustment for most any unit with limiter caps, and being an MS series most likely has them. You aren't supposed to adjust them beyond the limiter cap limits, as it could become out of compliance, which would violate EPA regulations for tampering. Technically we can't advocate it but if you had an emissions analyzer...
A too-rich condition can be caused by the inlet needle hinge/arm being too high, which you are correct in thinking should be level with the gasket mating surface for that series carb (NOT ALL of 'em though). See http://www.zamacarb.com/tsf_disassemblyc1u.html. Justin has a valid point about clogged exhaust on a 2-stroke, although rare on a saw. The muffler has a spark-arresting screen, which might be restricted. You said you put a new kit in it - do you have the metering diaphragm gasket on first, then, the diaphragm? If in wrong order has same effect as needle lever being too high. Double check the pump diaphragm and gasket with the old ones - if there's any extra holes or holes in the wrong place could be allowing fuel to be drawn into the impulse hose directly into the CC. On diaphragm carbs, the most common cause of one running too rich is a collapsed metering diaphragm, secondly a worn inlet needle that shifts to from side to side. There are other causes, clogged air filter for instance. Clogged exhaust isn't really a cause of rich running, it's a result of rich running or lugging. Did you use an OEM kit?


----------

