decomp for high compression ms260?

[thompsoncustom]

I have a high compression ported ms260 that's a real pain to pull over I was wondering if there is a different model decomp I could use to make it easier as I already broke the recoil once. timing is advanced around 5 degrees and squish is .018.

just tired a ms290 one but it won't start with that one.

 

[Mastermind]

I have a high compression ported ms260 that's a real pain to pull over I was wondering if there is a different model decomp I could use to make it easier as I already broke the recoil once. timing is advanced around 5 degrees and squish is .018.

just tired a ms290 one but it won't start with that one.

372XP decomp.

 

[thompsoncustom]

372XP decomp.

Thank you Sir.

 

[drf256]

I see you stated 5* advanced, but have you checked your flywheel key?

Like Moobs said, the big Husky decomp (not the 3120) with the blue button is your go-to.

I‘m a bit surprised it’s hard to start though. I’ve had some pretty high compression 1121 series and never had an issue, and I am a guy that prefers a decomp on saws.

 

[sundance]

372XP part number looks to be 584288701. Black top, not blue so I'm confused.
Assume the Husky decomp would work on a 036 pro as well?

 

[Mastermind]

372XP part number looks to be 584288701. Black top, not blue so I'm confused.
Assume the Husky decomp would work on a 036 pro as well?

Older 372 decomp is not the same as the XT version.

 

[huskihl]

If you want the one that bleeds off more compression, you want one from a side decomp model

 

[sundance]

If you want the one that bleeds off more compression, you want one from a side decomp model

I'm not a Husky guy so that doesn't help. Any chance of a part number? Or at least a Husky model number to start from?
TIA

 

[sundance]

Older 372 decomp is not the same as the XT version.

I'm not sure how to interpret this?

 

[Mastermind]

I'm not sure how to interpret this?

IPLs are available on HL Supply's website

 

[beaglebriar]

Husqvarna 503715301 Decompression Valve Chainsaws 254 261 372 388 357 365 371

Valve Poulan Pro PP505 Poulan Pro PP425 Jonsered CS2188 EPA Jonsered CS2188 Jonsered CS2186 EPA Jonsered CS2186 Jonsered CS2171 EPA Jonsered CS2171 Jonsered CS2165 EPA Jonsered CS2165 Jonsered CS2163 EPA Jonsered CS2163 Jonsered CS2159 EPA I Jonsered

fixmytoys.com

 

[thompsoncustom]

I see you stated 5* advanced, but have you checked your flywheel key?

Like Moobs said, the big Husky decomp (not the 3120) with the blue button is your go-to.

I‘m a bit surprised it’s hard to start though. I’ve had some pretty high compression 1121 series and never had an issue, and I am a guy that prefers a decomp on saws.

it's got me a bit confused as it's not all that high on the compression side last time I looked it was at 170psi.

funny you mentioned the flywheel key as I took it apart today to check just that. everything looks good there.

ya she's a hard starter you have to have the piston going down to even have a chance to turn it over.

I planned on going back in sometime and raising my transfer, fixing my fuel pooling (ms460 carb and 038 boot) and upping the compression some more but I need to get this thing to turn over easier first otherwise I'm gonna keep breaking recoils.

 

[huskihl]

it's got me a bit confused as it's not all that high on the compression side last time I looked it was at 170psi.

funny you mentioned the flywheel key as I took it apart today to check just that. everything looks good there.

ya she's a hard starter you have to have the piston going down to even have a chance to turn it over.

I planned on going back in sometime and raising my transfer, fixing my fuel pooling (ms460 carb and 038 boot) and upping the compression some more but I need to get this thing to turn over easier first otherwise I'm gonna keep breaking recoils.

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

 

[thompsoncustom]

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

Thanks means the compression has nothing to do with it. when I had the ms290 decomp in it pulled smooth as butter so that rules out the recoil being the problem just bleed to much compression to pop off.

 

[drf256]

Pull the wire off the plug and pull it over. See if it makes a difference in the amount of force needed. Eliminates the ignition as cause of hard starting.

I’ve had these saws at 275 psi and 30 thou off the crank key with no difficulty in starting issues. And I am old enough to appreciate a decomp valve. I don’t really care to prove I am strong enough to do something anymore if there is an easier way. Decomps make it easier on everything and everyone.

 

[thompsoncustom]

Pull the wire off the plug and pull it over. See if it makes a difference in the amount of force needed. Eliminates the ignition as cause of hard starting.

I’ve had these saws at 275 psi and 30 thou off the crank key with no difficulty in starting issues. And I am old enough to appreciate a decomp valve. I don’t really care to prove I am strong enough to do something anymore if there is an easier way. Decomps make it easier on everything and everyone.

I'll make sure I do that today and report back.

275psi wow, how did the saw like that? I was hoping to land around 200psi didn't figure the saw could handle almost 300psi.

 

[drf256]

The smaller bore saws like lots of compression. I didn’t really aim for that psi, its more of a side effect from dropping the jug as much as possible to get the ex roof low enough.

Compression adds heat. The smaller bore jugs have relatively more cooling surface area than their larger counterparts.

 

[thompsoncustom]

ok so I got home and pulled the plug wire and it turned over nice and easy. put the plug wire back on and still nice and easy to pull over which is normally the case once you've rotated the motor a couple times it's pretty good.

walked by it again an hr later and decided to pull on it again, back to hard starting.

 

[thompsoncustom]

Pull the wire off the plug and pull it over. See if it makes a difference in the amount of force needed. Eliminates the ignition as cause of hard starting.

I’ve had these saws at 275 psi and 30 thou off the crank key with no difficulty in starting issues. And I am old enough to appreciate a decomp valve. I don’t really care to prove I am strong enough to do something anymore if there is an easier way. Decomps make it easier on everything and everyone.

so it's not ignition timing. played with again this evening pulled it over once and it was hard so I pulled the plug and it didn't get any better so I put it back on and pulled it over till it got better and fired up.

 

[drf256]

Are you sure the jug is square to the base?