Stihl MS210 fault and non OEM parts

[Stubby]

1 hour ago, roys said:

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.

Coil breaking down when it gets hot .

[openspaceman]

4 hours ago, roys said:

PS no primer / purge valve on this saw.

I have  three 30 year old Husky 262s, one of them is always fine, the other two  will play up after very hard use logging up in the heat. Worst is if I let them run out of fuel then they will often not fire up readily. I put this down to vapour/air  locks in the carburettor somewhere. With more modern saws you can use that bulb to run cool petroil through the carb.

 

When the huskys get difficult to warm start I find I need to use the choke for one pull to suck fresh fuel through and then several pulls on half throttle lock. I keep meaning to the strip the carbs but never enough time so I just pick up another saw.

[spudulike]

130 on the first pull is damn good, 70-100 is much more common so that is all fine.

I would try to use a piece of printer paper to set the coil to flywheel gap. I had a 460 once that was exactly like yours and just had a larger coil to flywheel gap than was normal.

This is worth a look at.

Other than that, has the carb low screw been set correctly? Around 1.25 turns out should ensure it is workable...as long as the limit cap isn't on, if it is, just wind it out fully.

I always check everything and if it all fails, it has to be the coil. Throwing £70 at a coil at the first stage isn't in my work ethic. BTW, aftermarket coils are pretty crap at best - best get an OEM one and second hand if possible.

[spudulike]

Also check the compression is good when hot.

Does the saw start OK if left for an hour?

[roys]

Cheers spud

I took the coil off and gave the area a good clean and reset the gap using a business card, I wound the H and L screws fully in and out 1 turn as that is what is on the wee diagram on case.

Good point re checking compression when hot, not tried that yet.

[spudulike]

The hot compression will be interesting, 130 on one pull when cold is very good but if a saw runs and revs well when cold then not start when hot, it may be the coil. Try closing up the gap a little, I have seen old flywheels lose their magnetism before.

 

Have you checked the fuel tank breather? This can give running issues, bogging and lack of power after a bit of running.

The simple way is to drain the fuel tank, pull the fuel pipe off the carb and use a Mityvac on the fuel tank on vac setting to see if the breather is allowing in air.

[roys]

Haven’t checked the breather, but I opened the fuel tank cap when it wasn’t starting, refitted, but it still wouldn’t start, there is a used coil on eBay, might buy that, if it’s not that it will be a good spare anyway. I will also nudge the coil in a touch.

Cheers

[roys]

1 hour ago, spudulike said:

Also check the compression is good when hot.

Does the saw start OK if left for an hour?

Certainly does after a couple of hours, not sure after an hour.

[spudulike]

2 hours ago, roys said:

Certainly does after a couple of hours, not sure after an hour.

So the heat is definitely the issue.....just depends if it is killing compression or spark 

You could close up the plug gap as a test, try 0.25mm, it will make it easier to get a spark.

Not a solution but may help to determine if it is the coil or top end.

Looks like a hot compression test and regapping the coil and plug may give you the info to fix it 

[bmp01]

A bit random given the direction indicated by Spud but have you fed the saw a dribble of fuel, (down the plug hole) when it doesn't want to go? A cough or quick rev and die = carb problem, no sign of it running suggests compression or spark problem. Oh, and take a look at the plug as you take it out, looking to see if its dry or wet with fuel. If the latter then dribbling in extra fuel not likely to help...

 

130psi after one pull - weetabix for breakfast?  Or gauge is measuring small psi's .... its a standard ms210 ? Much carbon in the exhaust or exhaust port?

Regarding engine temp after running - although it might feel warm to touch after its stopped for 15 mins the cylinder is relatively cool compared to running temps. Surrounding fuel, ignition components will have a bit of heat soak though.