Jiffy/Tecumseh experts?

[Hesperus]

I have the last of the STX Pro 2hp models to have the Tecumseh engine.  My question is in regards to the muffler.  It is quite restrictive that is obvious.  What I wonder by looking at it is could this be a catalyst muffler?   The exit is WAY small, but even beyond that I haven't been able to see where the passge through the baffle is.  It almost seems based on the weight and size that this is a catalyst style like we see on many newer chainsaws.  Opening the muffler helps with starting, response, and performance.  The only trick would be how to do this without making it excessively loud. 

[Hesperus]

Nobody from Jiffy or teh Pro Staff here?

[Wiener]

Parts Manual just calls it a muffler, with a single part number.

That's for the 2500 and 3500 series.


Wiener

[blacktrap]

I have the same auger and I dont think it is a catalyst.  Just an oversized muffler. 

[dkfry]

Its a large muffler with baffles inside it. I took mine off and drilled a little larger exit hole. Didn't do anything noticable (performance wise) which I expected. Just helps any residual oil to blow out easier.

[Hesperus]

I suppose I may end up ordering a new one, dissecting mine and go from there.  Enlarging the muffler outlet alone will not necessarily do much of the baffle is tight.  I still think it may be a catalyst type.  Not much to them, just restrictive.

[jepik]

hesperus...I dont mean to steal your post..but I have the same auger...tough starting..how do you first start your auger..thanks

[two_fish_tommy]

clean it out but dont drill it out you will take away from the engine life, those engines are made to have a spec amount of back pressure you wont know the differance right away but it wont last as long.

[Fisherman 1]

Somebody always has to try and improve on what the manufacturer does, whether or not the outcome has the desired effect is in direct ratio relation to how much the owner will cry when the damm thing doesn't work like its supposed to.

[dkfry]

clean it out but dont drill it out you will take away from the engine life, those engines are made to have a spec amount of back pressure you wont know the differance right away but it wont last as long.

False. With the small amount the exit hole would be enlarged it is highly unlikely that the needle setting will even be affected. With the proper carburetor setup and adjustement the engine will run fine and last a long time (just as long as stock) even with little to no backpressure. You want exhaust velocity and scavenging.

I suppose I may end up ordering a new one, dissecting mine and go from there.  Enlarging the muffler outlet alone will not necessarily do much of the baffle is tight.  I still think it may be a catalyst type.  Not much to them, just restrictive.

The problem is you will still have the fixed needle carburetor on the auger which cannot be adjusted. You go changing things around too much with no adjustment on the carburetor the auger will end up running worse than before. The muffler on my Jiffy Stealth is large also, about 3"x3"x7" roughly and it has no catylist whatsoever in it.

[Hesperus]

hesperus...I dont mean to steal your post..but I have the same auger...tough starting..how do you first start your auger..thanks

There is no doubt they can be tough to start.  Quality gas is a key.  No ethanol, and use stabil.  I run Klotz oil at 50:1.  Choke it and pull.  Decomp valve is often necessary due to recoil geometry.  I haven't used mune much.  Runs pretty decent, but a bit cold blooded until warmed up fully.

clean it out but dont drill it out you will take away from the engine life, those engines are made to have a spec amount of back pressure you wont know the differance right away but it wont last as long.

That thing is SO stuffed up it's pathetic.  Modification in moderation should be just fine, BUT simply enlarging the exit wil not be enough.  Need to flow more through the baffle as well.  The trick is not to make it too loud.

Somebody always has to try and improve on what the manufacturer does, whether or not the outcome has the desired effect is in direct ratio relation to how much the owner will cry when the damm thing doesn't work like its supposed to.

I appreciate your concern.

If this wasn't a clamshell engine I'd be tightening up the squish and possibly doing some mild port work as well.  I've had great success with my Husqvarna chainsaws and have yet to wreck anything that I couldn't afford to replace.

False. With the small amount the exit hole would be enlarged it is highly unlikely that the needle setting will even be affected. With the proper carburetor setup and adjustement the engine will run fine and last a long time (just as long as stock) even with little to no backpressure. You want exhaust velocity and scavenging.

The problem is you will still have the fixed needle carburetor on the auger which cannot be adjusted. You go changing things around too much with no adjustment on the carburetor the auger will end up running worse than before. The muffler on my Jiffy Stealth is large also, about 3"x3"x7" roughly and it has no catylist whatsoever in it.

This is true, but I doubt it wil be a factor.  They tend to burn pretty rich anyhow.  Funny how they seem so lean to start yet burn so dark.  I think a lot of this is the muffler restriction.  Most of my chainsaw muffler mods result in a faster idle speed and better starting.

[dkfry]

What oil are your running and what ratio?

[Hesperus]

Klotz Super at 50:1

I run one oil in one ratio for my saws, drill, and the Lawn Boy even though L-B calls for 32:1.

[Hesperus]

hesperus...I dont mean to steal your post..but I have the same auger...tough starting..how do you first start your auger..thanks

I used a Unibit (step drill) for nice hole enlargement.  I enlarged the muffler exit to 1/2" and then took a 1/2" drill and went through the muffler inlet and made a hole in the baffle.  This seemed to help starting a bit and noise is not bad.  Far from a radical mod and easily reversed with a new muffler.