661 exhaust leak

[skylogger]

Hey guys I got a new 661 it runs perfect but has a small leak around exhaust, I took the muffler off and back on made sure everything was snug but no change. I'm no pro but figured it doesn't matter what say you?

 

[Chainsaw Jim]

Take it back to the dealer and see if they'll pull a muffler off the shelf under warranty. If it is past the warranty then you'll have to get it welded if you want your saw to stay pretty.

 

[stihlman441]

Use a high heat liquid gasket

 

[super3]

If it is past the warranty then you'll have to get it welded if you want your saw to stay pretty.

What are you seeing that needs welding?

 

[Moparmyway]

That gasket/heat shield has 2 dimples in it and sometimes they get in the way. I hammer them flat then re-install without any sealers

 

[Chainsaw Jim]

What are you seeing that needs welding?

What are you seeing that needs welding?

That would be obvious unless you're just trying to point out that it is only leaking from between the heat shield and muffler like I obviously may not have noticed when viewing it on my small phone instead of a large computer monitor after correcting the angle for optimum viewing pleasure.

 

[skidooguy]

My new 461 did the same thing. I'm glad you made this post. I'll look into it a bit further as well. Mine spit that nasty smelling ultra oil all over the clutch cover. Kinda tainted it right away I felt.

 

[skylogger]

That would be obvious unless you're just trying to point out that it is only leaking from between the heat shield and muffler like I obviously may not have noticed when viewing it on my small phone instead of a large computer monitor after correcting the angle for optimum viewing pleasure.

Sorry about that crooked pic i did it on my phone and thats how it came out it gets on my nerves too!

 

[skylogger]

Here's a better pic of it.

 

[mdavlee]

Check the muffler bolt torque too. If the gasket isn't eat up it should seal.

 

[Deets066]

Here's a better pic of it.
View attachment 23458

Looks like it could be runnin a tad on the lean side. Do you know what coil you have?

I'd pull the plug out and post up a pic

 

[Adirondackstihl]

Whenever I build a saw I always take a wide mill bastard file and mill the exhaust port mating surface. You'd be shocked to see how un-flat (is that a word?) they are from the factory. Every single one that I've seen was at least a few thou if not 20 from being perfect.
That's your problem.
So unless you want to remove the cylinder.....I wouldn't worry about it. It is what it is.

EDIT: the mating surface of the muffler itself is also usually an issue. That too, gets hit with a file.

 

[skylogger]

Thanks for the tips guys I figured it wouldn't effect how the saw ran, as for running lean it has the 4701A coil and runs really rich right now i only have 7 or 8 tanks trough it. The second pic i posted was after the first tank, i noticed the leak when the guy handed it to me at the dealership after he piss rived it to the point of near explosion

 

[Deets066]

Thanks for the tips guys I figured it wouldn't effect how the saw ran, as for running lean it has the 4701A coil and runs really rich right now i only have 7 or 8 tanks trough it. The second pic i posted was after the first tank, i noticed the leak when the guy handed it to me at the dealership after he piss rived it to the point of near explosion

Ok, the piss rev explosion might explain it. Lol

 

[Chainsaw Jim]

Whenever I build a saw I always take a wide mill bastard file and mill the exhaust port mating surface. You'd be shocked to see how un-flat (is that a word?) they are from the factory. Every single one that I've seen was at least a few thou if not 20 from being perfect.
That's your problem.
So unless you want to remove the cylinder.....I wouldn't worry about it. It is what it is.

EDIT: the mating surface of the muffler itself is also usually an issue. That too, gets hit with a file.

Definitely a must do.

 

[Wilhelm]

Check the muffler bolt torque too. If the gasket isn't eat up it should seal.

I burnt up the muffler gasket on my PS-7900 recently.
What didn't burn most likely got blown apart/away.
It additionally cost me the loss of two muffler bolts.

I'd get a new gasket and replace the current one as it might be already damaged!

To make clear the "burned muffler gasket" - I had metal remnants of the gasket dancing around in my PS-7900's muffler.
Yes, the OEM PS-7900 muffler gasket features a steel core.

Also the aluminum heat shield got slightly damaged from loosing the gasket, I have added one to my shoping cart.

A new OEM muffler gasket will set You back 1-2$, but give You some serious peace of mind.

 

[Adirondackstihl]

STIHL exhaust gaskets are completely made out of stamped steel. No fiber

 

[skylogger]

Alright deets I ran about a tank and a half through it today and pulled the plug it looked good to me but im a tool. I did noticed that it kind of found a sweet spot and was running like a scalded dog today.

 

[skylogger]

 

[Deets066]

Looks good to me, don't look like a lot of run time yet