Base gasket delete question

[doubletrouble]

I am thinking of deleting the base gasket from my chainsaw. Is there an average or standard thickness to these gaskets? I measured the squish (by inserting solder through the spark plug hole and checking it that way) and I have .033 now. I loosely measure the case gasket with a digital caliper and it measured .019 so if the base gasket is of the same thickness wouldn't that bring the piston to close to the top of the cylinder if I were to delete the base gasket? if I understand correctly the desired squish is in the area of .020
Thank for any replies

 

[cuinrearview]

Yes, and yes your understanding is correct.

 

[Chris-PA]

They are often around 0.020". You could find some card stock that is around 0.013" and make your own base gasket.

 

[doubletrouble]

And if card stock is used should I use a sealer on both sides as well? Like the yamabond?

 

[cus_deluxe]

ive cut gaskets out of beer/soft drink cans as well, with a tiny bit of sealer on both sides. Seems like it gave .008-.010 if i remember right

 

[doubletrouble]

That's a good idea using the thin aluminum for a gasket.

 

[Chris-PA]

And if card stock is used should I use a sealer on both sides as well? Like the yamabond?

I would smear it with a thin coat, if only because thinner stock will be less compliant than the original gasket, and less able to conform to surface imperfections.

 

[blsnelling]

It would be helpful to know what saw you're working on.

 

[doubletrouble]

It's a timberpro cs6150.

 

[ANewSawyer]

Chinese saw. Great to learn on!!!

I have a "policy" to do new things (read: experiment) on cheap stuff so that if I blow it up, it doesn't break the bank to repair.

 

[doubletrouble]

That's why I'm considering it. I still don't want to go crazy though. Don't want to push the limits and blow it up, I do use it regularly.......

 

[Chris-PA]

That's why I'm considering it. I still don't want to go crazy though. Don't want to push the limits and blow it up, I do use it regularly.......

If it hasn't blown up yet, chances are good it won't. The basic design is sturdy and a little compression increase won't break it.

 

[doubletrouble]

Right, I agree. First I might consider a muffler mod. I just have to figure out how to do it. The muffler is a 2 piece design but one of the pieces is crimped over the other. I don't know if I trust my welding skills to weld it back together if I were to cut it apart. May try to see what I can do without disassembling it.

 

[Chris-PA]

Right, I agree. First I might consider a muffler mod. I just have to figure out how to do it. The muffler is a 2 piece design but one of the pieces is crimped over the other. I don't know if I trust my welding skills to weld it back together if I were to cut it apart. May try to see what I can do without disassembling it.

I'd do the muffler mod first. My clone ended up at around 0.032" after the gasket delete, and it runs very well. Zenoah engines generally have small combustion chambers, but I don't know about the redesigned engine in that one. Still, you may not get much from going to 0.020".

Do you really have to uncrimp it? Isn't that the dual outlet muffler? I would think you could drill or use a die grinder to add more holes in the baffle through the exhaust port hole.

Maybe post some pictures of what you've got to start with.

 

[doubletrouble]

I'll post some pics tomorrow. I'll be cutting in the morning so it'll be in the evening. I could probably do something from the exhaust port side. Seems to me that the "guts" are attached to the front section ( opposite the exhaust port.
Oh, yes it is a dual port exit.....

 

[drf255]

Aluminum roof flashing is generally .008-.010. It's thin/soft enough to use a paper punch for the bolt holes. Should get you where you wanna be.

IIRC, a soft drink can is .002-.003.

I'd coat both sides with sealant.

 

[doubletrouble]

Here is the inside of the muffler.

 

[Chris-PA]

Here is the inside of the muffler.

View attachment 560701 View attachment 560702

Well, there's the problem - that is a cat muffler and those filaments packed in there are quite restrictive. I'd buy one of the dual outlet mufflers off eBay, as they probably won't be cat mufflers.

The good news is you can expect large gains just with the muffler. I'd fix that first, and leave the cylinder on until you see how it runs. If you want to you can eventually put a degree wheel on it and see what the port timing is, and go from there.

http://www.ebay.com/itm/Muffler-Muf...573338?hash=item33c90f939a:g:nRwAAOSwdGFYq75J

 

[doubletrouble]

That's a cat muffler?? I guess I pictured something way different. I'm more used to cats in a vehicle I guess.
Is there a way to just cut the cat out of it? Just curious.....

 

[Ozhoo]

A more industrious man would figure out how to split the muffler to remove the cat. Us with less patience and low moral value would use a large drill bit to unleash hell. The cat will start to break apart and you can remove it in pieces.