Chainsaw Repair

Until yesterday I would have bet that indexing plugs was hardly worth the effort, although I'm OCD enough to mark them anyway.  However, after running my freshly reassembled Poulan I had a bit of an opps when the intake worked loose - I stopped it quick when I noticed the idle all over the place, but still took a peek in the combustion chamber to make sure all was well.  I was surprised to see a clear stripe across the piston in the light coating of carbon that had built up.  It was offset and I was pretty sure it corresponded to the plug electrode location, so I put it back in to check, and sure enough it did.  I had recently put a new plug in and didn't worry about how the indexing worked out.

That's a long way from showing that it makes any measurable difference in output, but I figure if it makes a difference in the piston wash it must be having some effect.  Naturally I put one in that aligned better. 

I take painstaking efforts for the ported saws and have a drawfull of plugs for stock saws. If the strap aint where I want it, I grab another plug and try it. One time I went through allmost a dozen plugs before one lined up well enough to keep

Usually piston wash is more related to port design.

You'd think so, but yet there it was; a nice clean stripe offset to one side of the piston right in line with the plug ground tang.  The piston is not getting filthy black, just a little gray.

This pic shows a few different things ..............and was perfectly indexxed

Back when running the alky saws tried the  side cut, side gapping.  Suppose to give better spark I heard. I didnt see any difference so I went back to my bosch plus I used for alky saws. ws5e cooler plug

Also used to side cut, side gapping plugs for saws that were so tight they would close the gap with piston hitting.  I found my bosch plug would work in those too.  shorter and cooler ws5e , quit the side cutting.