Stihl MS210 fault and non OEM parts

[roys]

My trusty first chainsaw that I owned started playing up. I use this saw for mostly rhododendron bashing.

Use if most weeks and was using this week and it developed the fault of not restarting once warm. Did the usual, checked the fuel pick up filter, air filter, changed the plug, the fuel is fresh and it has not had stale fuel sitting in it.

Tried it still the same fault.

So I stripped carb out looked clean, made a new gasket for carb to cylinder, checked H and L in then out 1 turn, checked the spark looked weak, so I changed plug again and checked and reset ignition coil gap. Spark still looks weak.

Tried it again, started a little better but is bogging down if I press the throttle too quick.

Two questions:

Have I missed anything?

Are the clone coil and carb combined kits any good from eBay, as they are cheapish at £25, worth buying to try?

cheers gents

[ChrisNewport]

Not restarting once warm is IMO an invite to remove the exhaust and have a look at the piston, its a classic sign of a lean seizure.

[peatff]

Had similar on a 180 and cleaned the carb out with no improvement, it was the metering adjustment. Bent the arm up a bit and it was running perfect.

[openspaceman]

1 hour ago, ChrisNewport said:

Not restarting once warm is IMO an invite to remove the exhaust and have a look at the piston, its a classic sign of a lean seizure.

I've found that with a light seize even if it starts it won't tickover

[roys]

Thanks gents, unusual carb to me as I can’t see a metering arm to bend, all that appears to be in it is a couple of diaphragms, a choke flap and a throttle flap.

Edit, just used the oracle we call google and think I know what you mean now.

Don't like the sound of lean seize. Hope it’s not that. 

Edited July 24, 2021 by roys
More info

[openspaceman]

43 minutes ago, roys said:

Don't like the sound of lean seize. Hope it’s not that. 

As @ChrisNewport says it's easy to check, just remove the two exhaust nuts remove the screen (check it's not blocked) and pull the exhaust to reveal a view of the piston and rings through the exhaust port.

 

That's a clamshell engine so repair costs often exceed replacement price.

[roys]

Thanks gents, I will make that my next check, I am just in from a session with it.

I ringed up two or three pieces of timber with it, after each ring I stopped and started it no probs. I then went and got my splitting maul, split and stacked, so 10 or 15 minutes elapsed, tried to restart no joy. Took plug out reconnected and earthed it, pulled it over no spark. Can’t see any damage to kill wire.

Worth trying a clone eBay coil?

[openspaceman]

45 minutes ago, roys said:

Thanks gents, I will make that my next check, I am just in from a session with it.

I ringed up two or three pieces of timber with it, after each ring I stopped and started it no probs. I then went and got my splitting maul, split and stacked, so 10 or 15 minutes elapsed, tried to restart no joy. Took plug out reconnected and earthed it, pulled it over no spark. Can’t see any damage to kill wire.

Worth trying a clone eBay coil?

First try a different plug

 

I see you tried that. the other thing is to thoroughly pump the purge/primer bulb to make sure you are rid of any vapour locks

Edited July 24, 2021 by openspaceman

[spudulike]

The first thing I would do is check the compression cold then hot. You need at least 150 cold, more is good and around 130 hot is borderline. A visual through the exhaust port will tell you if you have a fried piston 

You can pull the saw over slowly and it should feel pretty punchy and springy as the engine is pulled over top dead center.

If this is OK, try bending the end electrode off an old spark plug and then test the spark in subdued light and pull it over hard. You should be able to get a spark with this modified plug hot and cold.

The carb gauze strainer may be partially blocked, take it out and look at it against a bright light using a magnifying glass. The carb l screw may be set lean, this can cause starting issues. 

Check the pump diaphragm small sealing flaps, these can get perforated by the holes underneath them. Check the metering diaphragm is still flexible and the metering arm is level with the sealing part of the carb body.

These carbs have accelerator pumps and it is always worth fitting new on a service. Usual symptoms of a bad pump are uneven idle.

 

 

 

 

 

[roys]

Got back to the saw this morning.

Put a compression tester on it, first pull went to 130# was up to 150# after three pulls.

Took the exhaust off, piston looked good, opened up exhaust box, not much in there a small metal tube with a few holes in it, nothing blocked or out of place.

Fuel gauze in carb looks ok.

Another new plug, ran it,  still no restart when hot.

Checked spark, it is definitely there, put a blanket over my head this time to get it nice and dark, glad nobody saw me😀.

So next step?, carb diaphragm kit or even new carb from eBay? Or is there anything else I should be doing.

Thanks again.

PS no primer / purge valve on this saw.

Edited July 27, 2021 by roys
Addition.