The Dreaded Dolmar Cat Muffler

[Mastermind]

In this thread I will be modding a Dolmar cat muffler from a 6400. I'm installing a ported 7910 top end, so I'll also be port matching the muffler to that jug.

First......the weights.

The cat muffler.

 

[Mastermind]

A 7900 muffler.

 

[Mastermind]

Now to open up the cat muffler.

I use a torch and heat the seam. Then work my way around it prying it open.

 

[Mastermind]

Then to remove the baffle.

 

[Mastermind]

And finally.......the cat and associated layers of *B-S.....

 

[Mastermind]

Now.......excuse me while I match the back half to the jug......

 

[Sty57]

In this thread I will be modding a Dolmar cat muffler from a 6400. I'm installing a ported 7910 top end, so I'll also be port matching the muffler to that jug.

First......the weights.

The cat muffler.

View attachment 35944 View attachment 35945

Holy Moly thats a lot of cat crap.........

 

[Mastermind]

It smells bad too Brian. LOL

 

[Sty57]

I can stand knee deep in cow poo.......one cat turd will make me lose my lunch.......

 

[exSW]

I can stand knee deep in cow poo.......one cat turd will make me lose my lunch.......

I got a barn cat. I'd don't know which one. Crapping right where we walk into the top of the barn.
Here kitty kitty kitty.

 

[Simondo]

Im in.......I rather like a neat and well maintained little Cat !!

 

[Mastermind]

I forgot to add the rest of the pics when I finished......duh.

The "modded" weight.



The garbage I removed.



Finished product.

 

[Definitive Dave]

clean work Randy!!

 

[Poleman]

VERY CLEAN work, Randy!!!!! Those things are a bugger...... I usually loose some skin, hair, get a nice burn and of course insult to injury.........metal slivers!!

What's your secret tool of choice to pry the crimping loose?? I know a lot of heat helps but ya still gotta get under it to understand crimp it.....

 

[Backtroller]

I used the craftsman version of these nips
They are not strong enough to bit through the stainless and the head acts like a fulcrum. I did break the head of one side while I was using it to crimp the case back together. I was worth it though.

 

[Mastermind]

I just use an old screwdriver. Lots of heat.....

 

[Backtroller]

Lots of heat is the key. I like the screen.

 

[TJ the Chainsaw Mechanic]

Cat mufflers are like having cat converters. Both rob power and sound. Both dangerous.

 

[tla100]

I pulled the cat out without taking it apart, lots of drilling and finally the drill bit caught and wound the cat around the bit. It took a few times to remove it all. This is on a 5105, but looks real similar. Just wondering if just the cat removed, is it still pretty stuffed up with the baffle in there? Don't got the saw running yet.

 

[David Young]

Not too bad on a 5105.
But if you take the deflected off the front you can drill through the remaining baffle. I use a uni bit and slow speed to make big chips easier to clean out.