Exhaust gaskets and sealants

[Brewz]

Sealing your muffler to the cylinder

I have a few questions about this area and would love to hear people's preferences and methods to get a good seal

I know they are a kind of "nothing" thing on a saw but I just can't seem to find something that will seal properly.

I mostly use the steel gaskets and these work well but always seem to leak a bit, leaving a oily dribble all down the back of the muffler and on the couch last cylinder around the exhaust port. This ends up burnt on and as we all know, is a *b-word to remove.

I tried one of the thicker grey gasket material ones to see if they would seal better, but it failed, burnt up and when I noticed the saw was running leaner by ear, I found the muffler rattling around loose and the gasket burnt up to a shadow of its former self.

I went back to the metal gaskets!

I was at the auto shop getting high temp black paint for a couple muffler restor's and bought some permatex copper high temp exhaust sealant to try and fill the little gaps left by the steel gasket.

What do you do?

 

[jacob j.]

Northwood Saw sells a metal/fiber gasket for many of the modern Stihl models that seals very well. I use them on saws as old as the 056 and as new as the MS-660.

I've had good luck with modern Husqvarna gaskets mostly. If I'm making an exhaust gasket- NAPA here sells a high-temp fiber paper that works well.

 

[Brewz]

High temp fibre paper
Now there is an idea!

To eBay.........

 

[Brewz]

Before I go ordering gasket material, I might try the gasket sealant in a tube on the muffler side, see how it goes.

Does anyone else seal their muffler with goo in tube of any sort?

 

[Simondo]

2 things I do to help out getting a good seal on "Final" instal is...
After making sure the muffler mating surface is flat by sanding down on a sheet of sand paper on a flat table ( if you can)and i have a new gasket of the sort the saw should have, I give the back of the muffler a spray with the heat paint.
Assemble before it dries and then leave it for a while before running the saw.
Cant say its full proof but it seems to work for me.

 

[Brewz]

I just fitted the muffler up to my 066 with the metal gasket.

I put on a bit of the permatex gasket sealant on each side of the gasket and will see how it seals after a couple of tanks.

The packet says it is good to about 450*c

Time will tell

 

[Warped5]

If I need to make a gasket, I cut one from Mr Gasket hi-temp (racing) material.

I also use the Permatex Copper spray. A couple light coats on each side works well.

 

[Keith Gandy]

Permatex Motoseal or Yamabond 4 has always worked for me

 

[smokey7]

I have found alot of used mufflers are no longer flat on the gasket surface. So I end up making them flat by macguiver methods and using a factory gasket or a hone made one outta what ever I have. Mufflers get so hot up to 600+ so I Gant believe some sealant stuff can hold up to that.

 

[Canadian farm boy]

I've been using the metal gaskets with the lead and fiber coating on them. They seem to be working good so far. They are thicker then the plain metal gaskets and once the muffler is mounted and tightened they form to the exhaust port and to the muffler. I like them.

 

[wigglesworth]

I never worry much about the dribble around the exhaust flange, but I have seen some that were excessive.

A friend of mine at work runs a dirt track car, with a SBC on methanol. According to him, they had a heck of a time getting header flanges to seal, until he ditched the gasket and went with high temp permatex. Said he hasn't had a problem since.

If it bothered me bad enough, I slap a new oem gasket on it, and try the permatex thing...