Makita 6401-->7901; ring gap 0.010" enough?

[jl4c]

I was lucky enough to find one of the old 7901 upgrade kits for my Makita DCS-6401 (which keeps the decomp on the left side of the cylinder) and have a couple of questions.

1. Is 0.010" enough of a ring gap?

2. If it's less than the correct amount, what is the best way to open it? Dremel and stone, file?

Thank you.

 

[Chainsaw Jim]

Leave it where it is.

 

[blsnelling]

I don't think I have ever opened up a chainsaw ring. .010" is fine.

 

[banditt007]

https://www.arboristsite.com/community/threads/dolmar-7910-ring-end-gap.296856/ This 7910 kit had the compression release on the top.

 

[jl4c]

Spark plug hole

 

[jl4c]

The actual gap is 0.008"; couldn't quite fit a 0.009" feeler gauge into it.

 

[cus_deluxe]

.004 per bore inch is the rule of thumb i have heard, i have opened up rings slightly on a couple saws, maybe being too cautious but i thought they were tight. Just used a good flat file. Doesnt take much to take .002 off, ask me how i know lol.

 

[jl4c]

.004 per bore inch is the rule of thumb i have heard, i have opened up rings slightly on a couple saws, maybe being too cautious but i thought they were tight. Just used a good flat file. Doesnt take much to take .002 off, ask me how i know lol.

With a 52mm piston that puts it right in the ballpark then.

 

[jl4c]

Finished the conversion today. Used the metal gasket, didn’t bother checking the squish. Fired right up. Thanks again everyone.