Chainsaw Repair

The standard spark plug gap for most chainsaws now days  is .5mm or .020".

I'm around a lot of model airplane gasoline engines and they mostly run a crank triggered, battery powered, CD ignition.

With the model airplane engines pulling a propeller, they are flown around at partial throttle most of the time. There's a tuning problem that occurs whereby if you have the idle, acceleration, and high speed mixture set correctly, they burble and sputter at partial throttle settings as the engine is not pulling hard and it is more or less like running the Chainsaw out of the wood.

Most new model airplane engines use the NGK CM6 spark plug from the Honda Generators. But the older ones use the BPMR6F tapered seat and BPMR7A gasket spark plugs. Everyone uses a shielded cap and wire so the caps have to match the spark plug being used including the tiny 1/4-32 plugs. I have found that you can interchange the corresponding tapered seat and gasket plugs in the same head with no problem.

People have found that to set the plug gap at .6mm or .024", the partial throttle burble problem is diminished somewhat.

Now these engines are running a battery powered ignition - not flywheel magnetos - so they have a hot spark at idle speed.

So this may not work as well on chainsaws and weed whackers? I have not tried it on my Chainsaws yet.


















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