Suitable base gasket replacement

[Lumptastic]

So on my ms 260 I swapped out the top end and threw it back together without the base gasket. Ran it without testing the swish but then the voice of reason got to me so I checked it 0.0012. Wasn’t making and contact but I’m sure soon enough a little bit of carbon would very easily fill that gap. I don’t want to put a oem base gasket back in +0.0023. Now I know I’m crazy. That’s already been well established but I’m considering cutting one out of a manila envelope 0.0006 that should put me right where I wanna be. Thoughts? It’s not my first time making gaskets. I had an old truck many years ago and the vast majority of the gaskets on that engine were old cereal boxes. Young dumb and mainly broke but they always held as well as any other

 

[singinwoodwackr]

So on my ms 260 I swapped out the top end and threw it back together without the base gasket. Ran it without testing the swish but then the voice of reason got to me so I checked it 0.0012. Wasn’t making and contact but I’m sure soon enough a little bit of carbon would very easily fill that gap. I don’t want to put a oem base gasket back in +0.0023. Now I know I’m crazy. That’s already been well established but I’m considering cutting one out of a manila envelope 0.0006 that should put me right where I wanna be. Thoughts? It’s not my first time making gaskets. I had an old truck many years ago and the vast majority of the gaskets on that engine were old cereal boxes. Young dumb and mainly broke but they always held as well as any other

Coated with sealer on both sides I don’t see why that wouldn’t work.
personally, I don’t see there is enough gain in eliminating the OE base gasket on a stock saw.

 

[thompsoncustom]

Like said above that works great just put some motoseal or some kind of gas proof sealer on both sides. I just did the same thing to get a 660 right where i wanted it.

you might be fine where it is tho I think you can run the 260 pretty tight. I ran mine without knowing for a year with the rings only gapped at .003 and that was on a ported, bigger carb, tight squish saw. I didn't put it back together that tight as it's not worth the risk but it didn't seem to mind.

On a small saw like the 260 or other 50cc saws .015 is fine.

 

[Lumptastic]

Coated with sealer on both sides I don’t see why that wouldn’t work.
personally, I don’t see there is enough gain in eliminating the OE base gasket on a stock saw.

Yeah my plan was to put a thin film of moto seal on the case side tighten the cylinder down so I’m not taking too long give it an hour or so them loosen it back up put a little on the other side and torque it down. I can’t say I know for sure how much it wil gain but at 0.0012 it has so damn much compression that trying to start it without the decomp you’d better be holding on to the saw well or it was coming up with the cord. I think #1 it really depends on the saw. Just a simple muffler mod on a 250 wakes it up and really makes a big difference where on others the difference isn’t nearly as drastic. #2 would be how far are you actually pushing the saw as far as it’s power limitations. If your only cutting 12” rounds for firewood you probably won’t notice much vs cutting a much larger log where you’ve got the whole bar buried and are using the dogs to really push your way threw. If your on the verge of stalling it out you’re definitely going to notice increases in torque

 

[thompsoncustom]

I can’t say I know for sure how much it will gain but at 0.0012 it has so damn much compression that trying to start it without the decomp you’d better be holding on to the saw well or it was coming up with the cord.

it will gain around 10 to 15psi

 

[ZeroJunk]

I have made them out of brass shim stock. Be a little expensive unless you know somebody who will cut you a little piece.

 

[NSEric]

Use a beer can for the gasket material and put motoseal on both sides of it.

 

[Gord404]

Just have a couple of rolls of gasket paper around my shop -10 and 20 thou in case needed-have a bunch of gaskets for most saws I work on but once in a while a rair bird has to be worked on, motoseal it down to the block and let it setup a bit and nothing on the top, works for me.

 

[Automender]

I made a gasket out of an aluminum can with sealer on both sides. It was .004 inches and sealer doubled that.