decomp for high compression ms260?

[thompsoncustom]

Are you sure the jug is square to the base?

no, when I lowered the jug a little I did it by sanding on a flat surface but it could be off.

 

[drf256]

I’ve seen side loading do weird stuff. You may want to send it to someone here with a lathe to confirm youre not way off. Pulling the jug may confirm some issues now.

Im not saying it’s that, but I saw it one time back when we did the “Warhawk” jug evaluations. The saw was impossible to turn over at times because the bore was not square to the base.

Is your jug oem? If its am, it could be tapered, out of round, out of square, etc…

 

[beaglebriar]

Might check your recoil pulley and smear some grease in there if it’s binding. I’ve seen these things with 230 psi compression and they still start fine with the bar mounted

This^^^ If you haven't done so yet it's worth checking out. I had a ms460 here that would act like it was locked up every once in awhile. I tore the saw down and checked everything, it was a worn out recoil. Could be a few different things but don't overlook the simple stuff.

 

[thompsoncustom]

I’ve seen side loading do weird stuff. You may want to send it to someone here with a lathe to confirm youre not way off. Pulling the jug may confirm some issues now.

Im not saying it’s that, but I saw it one time back when we did the “Warhawk” jug evaluations. The saw was impossible to turn over at times because the bore was not square to the base.

Is your jug oem? If its am, it could be tapered, out of round, out of square, etc…

it's AM so not worth sending it out will just cover up the issue with a decomp.

saw runs great otherwise but I do plan on pulling it back apart to do some work so I'll look it over when I'm in there.

 

[Jedd]

it's AM so not worth sending it out will just cover up the issue with a decomp.

saw runs great otherwise but I do plan on pulling it back apart to do some work so I'll look it over when I'm in there.

i am a muppet so have a couple of easy things for you to check that I have screwed up in the past and lead to weird things happening at the relatively low piston speed when reefing on the recoil. if the piston is old check if the the skirt is worn and the piston tipping slightly to catch a ring slightly (even skirt on the intake if it has been widened too far) or maybe just poor chamfers on the AM cylinder ports.