Jonsereds 49sp ring end gap

[rlamppa1]

Putting a new piston and ring in a 49. Anyone know the ring end gap number and does anyone have an extra air filter they would part with? Thanks.

 

[Lightning Performance]

@rlamppa1

0.009-0.012

 

[rlamppa1]

@rlamppa1

0.009-0.012

Thank You!

 

[Cantdog]

I'd prefer more like 0.005"-0.007" on a new ring

 

[Lightning Performance]

I'd prefer more like 0.005"-0.007" on a new ring

0.005 is bit tight during break in but will run in near 0.007 most times or more. Let us assume he is cleaning up a used cylinder so it will have some wear most times and new rings often won't be as tight.

 

[Lightning Performance]

I'd prefer more like 0.005"-0.007" on a new ring

0.005 is bit tight during break in but will run in near 0.007 most times or more. Let us assume he is cleaning up a used cylinder so it will have some wear most times and new rings won't be as tight.

 

[cuznguido]

1.5 thousandths (.0015) per inch of bore diameter is the usual standard, large and small alike.

 

[ray benson]

I have a file saved that listed ring gap
Ring gap new ring .2mm to .4mm .007" to .015"

Rule of thumb about .004" per inch of piston diameter.

 

[rlamppa1]

0.005 is bit tight during break in but will run in near 0.007 most times or more. Let us assume he is cleaning up a used cylinder so it will have some wear most times and new rings won't be as tight.

Thanks for the reply. Yes, I am using the old cylinder, it is in very great shape.

 

[Cantdog]

The point will probably be moot anyway.........I check end gap on every assembly but can't even remember the last time I had to file a ring on a saw motor using good quality rings like Caber.
To each is own..... but as I said I prefer 0.005- 0.007 on a single ring 49SP.......and I've put together a few and never had problem 1 using these numbers...it's rare to even have them be that tight......generally in a used cyl that's in good condition they fall in the 0.006- 0.009" range right out of the box.

 

[Cantdog]

I have a file saved that listed ring gap
Ring gap new ring .2mm to .4mm .007" to .015"

Rule of thumb about .004" per inch of piston diameter.

Yep........and on a 49SPs 1.73" bore that comes out to 0.0069"