Bob Murphy

Well, I have tested for continuity between the plug cap and the coil laminations - no connection. I then did the same test on the MS461 (which has a spark and kicks like a mule) - same result, no connection. I am using the 'buzzer' test on my multimeter, maybe I should be testing the resistance instead, I'll need to read the instruction manual for the meter! The MS880's flywheel is alloy, with two sets of magnets 180 degrees apart. I bought a Chinese replacement that was identical - right down to the small print disclaimers cast into it. That didn't change anything so I don't think its lack of magnetism. Yes I have tried different spark plugs - both of the same make and number and brand new ones that are totally wrong for the saw, just in case - no spark. I have set the coil-to-flywheel gap to 0.015" on both the 880 and the 461. I'll try and start them both today (I don't like running big chainsaws on a Sunday - I do have neighbours). I'll report back. The working coil on the 461 is totally different to that on the 880, it has three mounting setscrews whereas the 880s has two, The 461 coil is also considerably larger than the one on the 880. I am therefore unable to swap them. On the other hand I now have two Stihl coils and four Chinese coils for the 880. I have had a couple of weak sparks from the Chinese coils but nothing recently from the original Stihl coil or the new (ridiculously expensive @ £222.06) Stihl coil. Its not a 'broken wire' as everything is disconnected. I just have a coil, a flywheel and a spark plug ! The investigation continues, thanks for your input. Bob.

Thanks for the comments - some replies:- The continuity test used the buzzer on my multimeter connected between the cylinder head and the machine screw holding the coil. That obviously uses a battery and I didn't want to run voltage into the body of the coil in case there were some electronics inside. I haven't tried a test between the plug cap and the coil laminations I'll do that and report. Its nothing to do with the kill switch as I ensure its in the run position and have disconnected the kill wire at the coil in case it was earthing to the earth wire in the wiring sleeve. This is just a coil with a plug on the lead and a flywheel magnet. Nothing to do with timing or anything else - I'm just looking for a spark. I also have a Stihl MS461 - it can certainly kick back and can be difficult to start but its nothing compared to the brutality of the MS880 which is a beast. What annoys me is that I have seen videos of people (in America) using 880s where they appear to start with a casual pull on the rope. Mine has only done a couple of hours work so maybe when they are old and worn they become easier to live with, I may never know! I'll try widening the gap between the coil pole faces and flywheel magnets. I set it up with a feeler gauge so its easy to use 0.015" instead of 0.006". I have tested this in my workshop with the lights off (its dark) and have spun it furiously with the plug connected and resting on the head - no sign of a spark. When I do this with the 461 and the 181 I can see a good spark. The saw has only run for a couple of hours so everything is like new but I bought a new flywheel in case the magnets had lost their strength. There was no difference so the original flywheel is now back on. I'll keep plugging away at it (sorry for the pun !). I don't give up easily and "the truth is out there". Bob.

Hi, new member here. I have three Stihl chainsaws (and five other makes), my most recent being a brand new MS880 with a 48 inch bar (I have some large trees). This thing is driving me crazy, it was running for a while but was very difficult to start - it would kick back so violently it was hurting my hand. I fitted a mitten starter grip from a snow blower and a different (Stihl) decompression valve. Eventually it wouldn't start or fire at all. Investigation showed no spark. I have bought a few cheap Chinese coils (reputedly for the 880) but no joy. A couple of them have showed a weak spark when testing in a dark room but it won't run. I put a new flywheel on in case the magnets on the original were weak, no joy there. At last I decided to bite the bullet and bought a genuine Stihl coil - for £222.06 ! It is as dead as the others. I have checked the nasty plug cap fitting, tried a variety of spark plugs, put the original flywheel back on, tested the continuity between the coil mounting screws and the cylinder head but still no sign of a spark. I am setting the coil up with a 6-thou (0.006") clearance, the coil poles are not touching the magnets or any part of the flywheel. I am not new to engines of all types and it used to be said that "if Bob can't get it to run then no-one can" - cars, motorcycles, mowers, chainsaws, outboard motors I am familiar with them all - but this 880 is trying my patience. To be clear, I am removing the plastic covers, making sure that the spark plug is in good contact with the head, I have tried unplugging the earthing stop cable in case it is shorting somewhere and pulling the starter rope fast in a dark room - no spark. I have tried putting it all together and starting it as a normal saw in case I'm not seeing the spark. Same result - no life. There is loads of compression, the decompression valve works . . . WHAT AM I DOING WRONG ?? Its not a timing issue and spinning the flywheel magnets past the coil poles should produce a spark at the plug, but that isn't happening. Any bright ideas? Is there someone somewhere who can test coils in isolation? I don't have any hair or I would be pulling it out. Bob Murphy, in Central Scotland.