Squish , base gasket

[STOVE]

When checking squish on my 590, is there a specific wire thickness used to test?

From what I have gathered the line to stop at is around .020

I debating doing the delete on my cs-590. Do you replace the gasket with anything?

 

[Mad Professor]

Use a thin solder. Check thickness with calipers. You probably want something 0.030-0.040"

Gas resistant sealer if no gasket. Dirko Yamabond......

 

[STOVE]

Use a thin solder. Check thickness with calipers. You probably want something 0.030-0.040"

Gas resistant sealer if no gasket. Dirko Yamabond......

Traverse creek has a reduced thickness base gasket however it is out of stock. I assume a thin layer of the Yama is spread on the base with some holdback from all the edges to account for spreading ?

 

[Chevboy0167]

I have been using an old roll of Kester 44 solder at .031" thick. 60/40 Rosin core of course. NO acid core solders!

Any thin electronics solder will suffice.

 

[NSEric]

I did a base gasket delete to my 590 along with porting. The gasket was .016 or so thick, it's not a huge difference.
I used motoseal instead of the gasket. It still has .030 for squish, you can safely remove the gasket in the 590.
I would widen the exhaust port while you have the cylinder off, it's pretty small stock.
If you cant raise the transfer ports I wouldnt do any other grinding other than widening the exhaust, dont raise it without raising the transfers too. There's nothing to be gained grinding on the intake or lower transfers in that saw so dont waste time doing it.
On mine I raised the transfers and the exhaust port both just under 2mm to get the exhaust at 108 atdc and the transfers at 126 atdc.

 

[alexcagle]

When checking squish on my 590, is there a specific wire thickness used to test?

From what I have gathered the line to stop at is around .020

I debating doing the delete on my cs-590. Do you replace the gasket with anything?

My 2 cents
After 20 years of experimenting , I've let the engineering money that the manufacturers spent be good sufficient for me.
If you increase compression, you increase lower rod bearing stress, and risk crank bearing pocket elongation.
It can also risk scoring from higher heat generated from increased compression.
In other words, it generally significantly shortens the life of the engine.

Wasps prefer Stihl....

 

[J D]

Traverse creek has a reduced thickness base gasket however it is out of stock. I assume a thin layer of the Yama is spread on the base with some holdback from all the edges to account for spreading ?

You can make a base gasket to get whatever specific thickness you want using gasket paper, cardstock, even an aluminium can.
All saws are different so its important to measure the squish so you know what you have.
Make sure you have enough fuel rated sealant to seal without it going any further than the sealing surfaces. Vac & pressure test afterwards!

 

[lone wolf]

My 2 cents
After 20 years of experimenting , I've let the engineering money that the manufacturers spent be good sufficient for me.
If you increase compression, you increase lower rod bearing stress, and risk crank bearing pocket elongation.
It can also risk scoring from higher heat generated from increased compression.
In other words, it generally significantly shortens the life of the engine.

Wasps prefer Stihl....
View attachment 1250330

Yeah, I don't do that anymore either, but have had great results with small timing advances and opening exhaust a little.

 

[STOVE]

My 2 cents
After 20 years of experimenting , I've let the engineering money that the manufacturers spent be good sufficient for me.
If you increase compression, you increase lower rod bearing stress, and risk crank bearing pocket elongation.
It can also risk scoring from higher heat generated from increased compression.
In other words, it generally significantly shortens the life of the engine.

Wasps prefer Stihl....
View attachment 1250330

Yeah, I don't do that anymore either, but have had great results with small timing advances and opening exhaust a little.

I may just leave it be. It’s a firewood bucking saw. I do not fell anything. I don’t think it’s got 10 tanks through it yet. So it may wake up some more. I find all of the DIY enhancements to be super interesting and fun but I also like to keep my stuff for a long time.

The $20 premade timing advance key had me intrigued untill I realized I didn’t own most of what I needed to do the teardown.

I should invest In a few of the items I’ve seen for some basic teardowns.

 

[lone wolf]

I may just leave it be. It’s a firewood bucking saw. I do not fell anything. I don’t think it’s got 10 tanks through it yet. So it may wake up some more. I find all of the DIY enhancements to be super interesting and fun but I also like to keep my stuff for a long time.

The $20 premade timing advance key had me intrigued untill I realized I didn’t own most of what I needed to do the teardown.

I should invest In a few of the items I’ve seen for some basic teardowns.

Leave it be less trouble. Buy a faster saw if you feel so inclined.

 

[Lee192233]

My 2 cents
After 20 years of experimenting , I've let the engineering money that the manufacturers spent be good sufficient for me.
If you increase compression, you increase lower rod bearing stress, and risk crank bearing pocket elongation.
It can also risk scoring from higher heat generated from increased compression.
In other words, it generally significantly shortens the life of the engine.

Wasps prefer Stihl....
View attachment 1250330

I agree with you to an extent. However, I don't believe most guys put enough hours on a saw to notice a difference in engine life. Most saws die of straight gassing or running lean long before the bearings wear out.

 

[lone wolf]

I agree with you to an extent. However, I don't believe most guys put enough hours on a saw to notice a difference in engine life. Most saws die of straight gassing or running lean long before the bearings wear out.

Or the lack of base gasket and just sealant causes a VAC leak !

 

[ZeroJunk]

I used some brass shim stock on an 056 . I would have used the original, but could not keep it intact.
Worked fine. Think it ended up 25 thousandths or so cold.

 

[Lee192233]

Or the lack of base gasket and just sealant causes a VAC leak !

I'm a beer can base gasket guy.

 

[Lee192233]

Or the lack of base gasket and just sealant causes a VAC leak !

I do agree, if you're gonna do it it's better to cut the base and retain the factory gasket.

 

[lone wolf]

I do agree, if you're gonna do it it's better to cut the base and retain the factory gasket.

Yeah, I had it happen once, also a buddy of mine ,who is a STIHL Mechanic had it happen he figured it was from vibrations caused by no gasket. I tend to believe that.