High compression/decompression release problem

[Pioneer]

Just rebuilt a saw that has high compression, and it's kicking off the decompression release before it even gets a chance to fire. Anyone else experience this problem?

 

[pioneerguy600]

Common problem, use a decomp with a bigger diameter release hole/ bleed port, one from a 395 Husqvarna would likely work.

 

[chipper1]

Common problem, use a decomp with a bigger diameter release hole/ bleed port, one from a 395 Husqvarna would likely work.

Bingo!

 

[Pioneer]

Great, thanks guys, will give it a try.

 

[67L36Driver]

Drill the bleed port larger in tiny increments until it suits you. [emoji106]

A MS880 needs 1/16” for small skinny geezers. [emoji108]

 

[CR888]

I've drilled decomps with success before.

 

[Jkstihl]

Eat protein and use decomp plug.

 

[Yotaismygame]

I had this happen when using a cheap AM decomp. But after around 190psi decomp doesnt do much anyways.

 

[Canyon Angler]

.. decomp doesnt do much anyways.

...except make saws impossible to start.

Decomp on my 361 made me take it to the shop TWICE b/c it wouldn't start.
Got to the shop, the mechanic pulled on the rope and off she went.
I've never used a decomp since, and never had a lick of trouble, either, knock wood. Decomps are worthless IMHO.

 

[PP4218]

...except make saws impossible to start.

Decomp on my 361 made me take it to the shop TWICE b/c it wouldn't start.
Got to the shop, the mechanic pulled on the rope and off she went.
I've never used a decomp since, and never had a lick of trouble, either, knock wood. Decomps are worthless IMHO.

How does this make the saw impossible to start?

 

[PP4218]

https://www.chainsawspares.com.au/chainsaw-engine-cylinder-decompression-valve-for-s