Stihl MS211/C problem with power in the cut

[ChrisNewport]

Nothing on or around the throttle rod needs to be forced into place. Did you remove the top cover on the handle to remove/replace the throttle rod.

[Sawchip]

22 hours ago, John Rainford said:

I have uploaded the video, had to wait for my flu ridden son's computer skills, hence the delay. When I  start to engage the throttle , the engine revs increase as my finger pulls on the throttle trigger, but the chain does not move until I have pulled the throttle trigger half way back. 

 

Many thanks to spudulike, bmp01 and sawdust for helping me with this. I did think of swapping my brothers clutch and carb , but I didn't want to mess about to much with his new saw. I'll do as spud says and test  the carb and throttle linkage. That linkage to handle was a right pain when I reassembled the saw. It dropped out when I was dismantling the saw, so I didn't know how to reassemble it. I tried every possible thing I could think off, before realising that the linkage has to be forced under that little bit of plastic on the handle. No wonder they break, it's a terrible design. In the video commentary I use the word choke instead of throttle, so please be aware of this. This evening I spent an hour practising chain sharpening and studied the teeth before and after, using a magnifying glass. I noticed that the top of the tooth wasn't as sharp as I thought it would be, so started looking in to why this might be. At the risk of appearing foolish, I discovered that the files I have been using recently are 4.5 mm instead of the correct 4 mm size for my chains. I have no idea how this happened, but whatever the reason, it did. My calculations if accurate, mean that the files I have been using are 12.5% to big. Could this mean that the files are to big to get under the top part of the tooth to sharpen it ? Could this be why my chains are not cutting very well ?    I am a bit concerned about the amount of white smoke being omitted from the exhaust. 

 

ill try some new fuel with an accurate 50 : 1 fuel/oil mix to see if that makes a difference. Maybe the chain if not sharp on the top part of the teeth, is forcing the engine to work harder and overheat. I will get some 4 mm files and resharpen my chain, paying careful attention to the top part of the tooth to see if it comes out sharper. I had noticed that the saw chips coming from the saw immediately after sharpening were still very small, you may be able to see this in the video. Anyway, take a look and see what you think, and once again thanks for your help and knowledge sharing.

ms 171 181 211 copy.pdfYou "may" not have a proper manual ....I think some reading is in order for a better understanding of the issues you are having. 

 

[spudulike]

Going back to my comments and the later comments about the bar and chain, one more thing to try, whip the bar and chain off, replace the clutch cover and then rev the saw and see if it sounds a lot more peaky and revs very much higher. The bar and chain do seem pretty tight, have you checked the oiler is throwing out decent amounts of oil? with no bar and chain on, it should dribble out of the bottom of the saw in good amounts if revved flat out for 5-10 secs.

[John Rainford]

Thanks for the replies. I spent an hour tonight going through the checks that spud suggested. 

1. The throttle seems to be working well, with everything in the correct position. The butterfly opens to the full on full throttle so no adjustment needed there.

2. The choke is not partially on. The butterfly is parallel with the bore of the carb.

3. Don't think my air filter is the nylon mesh type, but I cleaned it thoroughly last week, and it does not appear to be blocked.

4. Carb H screw. This was interesting. The little plastic limiter cap was missing from the H screw. I know it was there prior to going for a service a few months ago, so, did the mechanic take it off for some reason ? I turned the screw in until it gently seated, which took 2.5 turns. Now the factory setting says three quarters of a turn out, so it was clearly set at the wrong setting. I have now set it back to the factory setting. I gave it a quick test in cutting and it does seem to cut better than before and there is less smoke being omitted from the muffler. 

I also looked at the issues that bmp01 brought up about the chain stopping very quickly. I spun the clutch with the brake off, and it spins freely. The brake seems to be acting as it should. When I put chains on the bar, I test the tightness by lifting the chain from the bar groove  about 1 cm and then let it ping back on to the bar. I will take another video this weekend and upload it to see if you can see any difference from the first video.

[ChrisNewport]

Without limit cap on h screw should be 1 and a half turns out. 3/4 is with cap on.

[ChrisNewport]

[spudulike]

Firstly - TURN THE "H" SCREW 1&1/2 TURNS OUT.....failure to do this will seize the machine.........3/4s turn is with the limit "plastic" caps fitted. Sorry for shouting but I have seen MS880s seized like this and don't need the work!

So, the machine runs better now and am not surprised with the carb being an extra turn out before.

Check the oiler - just fire up the saw with the side cover and bar off, rev lightly and wait for a trickle of oil to make its way down the side of the saw. Check the oil hole in the bar is clear of chip - that's the little hole that is in line with the oiler channel in the bar mount on the saw.

Once the bar is on etc, fire the saw up, point the end of the bar at something like a clean cut piece of wood, a piece of card etc, rev the saw and it should make a clear line of oil as it is thrown off the bar. Make sure you don't contact anything with the bar tip but this is a basic and best test for correct oiling.

Finally, when you have tensioned the chain correctly, if you hold the shaft of a screwdriver behind one of the teeth and whizz the chain forward with it, should turn freely and carry on spinning for a short while (1-3 inches) and NOT stop absolutely dead.

My tensioning technique is to put the side cover on, nip it up lightly so you can still move the bar up and down, tighten the chain until the bar tip starts to lift, hold the chain off the bar by resting your forearm on the chain brake lifting the chain between thumb and forefinger, aim for around 1cm gap between the chain and top of bar and tighten while still lifting. Once let go, the chain should be a light fit around the bar and the spin test above should work as described.

 

[spudulike]

We may sort this before 2021....hopefully!

[bmp01]

12 minutes ago, spudulike said:

We may sort this before 2021....hopefully!

Maybe.  Have you got a walk through for changing the oil pump just in case? Hopefully just chain tension - couldn't see any blueing on the bar. But slightly intrigued by the tops of some of the teeth which did have a bit of colour.

 

That saw's not going to know what's hit it when it runs right,  probably grenade itself in panic (well, lets hope not).

 

 

[spudulike]

Lets see what JR comes back with on the chain tension, oiler efficiency issues and see where that ends up....hopefully after he has re adjusted his carb!