Author Topic: Base Gasket  (Read 148 times)

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Offline The Ripper

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Base Gasket
« on: October 01, 2015, 07:13:31 pm »
Can someone explain what effect does base gasket removal  have on port timing and on RPMs.

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Offline aclarke

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Re: Base Gasket
« Reply #1 on: October 01, 2015, 10:12:46 pm »
Increases compression a very small amount, decreases exhaust and transfer port duration and Increases intake duration.  These changes typically make a slightly torqueyer saw. Use a thin paper gasket in lieu of nothing or machine the base and use a proper gasket.
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Offline The Ripper

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Re: Base Gasket
« Reply #2 on: October 02, 2015, 04:49:24 am »
Thank you for that info.

Offline oldpro

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Re: Base Gasket
« Reply #3 on: November 07, 2016, 06:50:39 pm »
I use Permatex Ultra Copper sealant.

Offline trappermike

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Re: Base Gasket
« Reply #4 on: January 01, 2019, 01:34:28 pm »
I agree 100% with what aclarke says,and I always use a thin gasket like him.Silicone is not the incredible magic some think it is,gasoline and pressure will weaken and dissolve it. Pulling the gasket gains a little low speed power,lessens high speed power,I don't do it.
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When the hammer drops the BS stops:Loggers sports competition!
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Offline Cut4fun .

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Re: Base Gasket
« Reply #5 on: January 01, 2019, 04:21:55 pm »
I dont do it anymore unless on my own saw and happen to be out of usable base gasket material etc. 
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Offline Al Smith

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Re: Base Gasket
« Reply #6 on: January 04, 2019, 10:04:45 am »
I prefer a gasket also .I have needed to use various materials to get the correct piston to head deck clearance because I took too much off the cylinder base or not quite enough  .If I recall at best your only talking 15 PSI of pressure,not much .
As far as sealants the clam shell Mac 10 series ,early models used gasket shellac ,Indian head ,thinned down permatex number 1 .Later used silicon .They didn't leak .

Offline trappermike

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Re: Base Gasket
« Reply #7 on: January 04, 2019, 12:07:37 pm »
One model that I found could use the gasket delete was the 3400 Poulan type saws which our shop sold,I actually compression tested one and was surprised to find it barely had over 100 psi stock,no wear. This was clearly a model that needed some compression help,I've found some 2-strokes will not fire much below 100 psi. Now nothing against those saws,they were amazingly reliable. I've also found as a general rule on most 2-strokes that for each thou you tighten the squish up you gain a pound of compression- tighten squish 020" you gain 20 psi,roughly...
Experience builds real horsepower...
When the hammer drops the BS stops:Loggers sports competition!

 

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