Chainsaw Repair

Generally speaking the points type ignition systems McCulloch used on the reed valve and 10 series saws are one of the most reliable systems ever made .

The earlier saws used the large coil where as the later series like to SP 105/125 used the smaller  10 series coils .

Much later of course they went to solid state being the PM 610 type which was used on saws such as the 805-850 , PM  610/650 and a host of others .These were pretty robust too as a general rule .

In all the 10 series saws I've worked ,which is many  only one appeared to have a bad coil .Oddly enough some time after I had replaced the offending coil which I saved I tried it on a mix match of saws to make another runner from parts and it worked .What was initially wrong with it to this day I have no idea . Magic maybe .