Stihl MS 211/C flooding issue

[John Rainford]

I posted here on another issue a few weeks ago and had some very useful replies so I thought I would do so again. I have a flooding issue on start up. My usual starting procedure is to put it in cold start, give it one or two pulls until I hear it trying to crank over, then move it to warm start and it usually starts on two or three pulls. However, after the carb screws were adjusted by a small engine mechanic, if it doesn't give me the cranking over sound after one or two pulls on cold start, it floods the engine and I can't start it at all. I took the plug out, it was very wet with fuel, and pulled the muffler which revealed a lot of fuel in the combustion chamber. Let it dry out over night and it started fine the next day. It is however, an ongoing issue, sometimes it will start and sometimes it floods. I'm wondering if the carb screw adjustment which was carried out resulted in to much fuel being sent from the carb to the combustion chamber, or perhaps there is another issue with the carb. I put a new carb kit in a couple of months ago, so I know the diaphragms are working. Could the metering needle be the issue? Any thoughts would be gratefully received.

[spudulike]

Difficult to say and would need to know that the machine also has good compression. One simple check on the L screw setting is to start the machine on the choke, let it pop then start it on the fast idle setting and it should rev like the throttle is open around 1/4 with a very obvious higher than idle revs effect. If it isn't doing this, the low screw is far too rich that could give you the symptoms you have.

It sounds like you are missing the POP of the first signs of combustion and that may be a number of issues such as poor carb setting, lack of compression etc.

If your machine has a decomp, don't use it and also, if it floods, remove the plug, turn the machine upside down, pull it over hard 5 times, replace the plug and then hold the throttle open fully and pull the saw over a few times and normally it will fire and run.....with lots of smoke.

[John Rainford]

Thanks Spud, I have been thinking that the compression may be low for a while now. I guess a compression test might be my next move. Do you or anyone else have any views on these cheap cylinders and piston kits from China. I just can't imagine that a cylinder and piston for less than £30 is of the quality needed for a chainsaw.

[peatff]

2 hours ago, John Rainford said:

Thanks Spud, I have been thinking that the compression may be low for a while now. I guess a compression test might be my next move. Do you or anyone else have any views on these cheap cylinders and piston kits from China. I just can't imagine that a cylinder and piston for less than £30 is of the quality needed for a chainsaw.

 

If there's no evidence of damage you just need a new piston ring. 

[spudulike]

If the saw is used for business and is a primary saw then it should get OEM, Meteor/Hyway, if it is seldom used and if it packs up it is of no consequence then fit whatever grabs you.....simple!!!

I never just fit a piston ring as if you are in the engine, you often pay £10 for a ring or £25 for a decent AM piston so fit pistons....sorry.....just what I do!