970 muffler mod help

[KMB]

I’ve been thinking about how I can open up my 970’s muffler. The muffler mod on my 260 was easy, but the 970’s muffler has more to it. Here are some pictures of the muffler. The first picture is of the front with the cover off, the second is of the back, and the last shows the cover on the front of the muffler.

So, does anyone have any ideas on what could be done? I think the pictures I’ve posted are self-explaining. If not, let me know.

Kevin

 

[Four Paws]

You could add an exhaust port or two on the front cover, or you could cut the tube out from inside the muffler. Also, drill some more holes in that baffle where the exhaust enters as it leaves the engines exhaust port. The design is simply to make a 'torturous path' for the exhaust gasses - this quiets it down a bit. Doesn't look too bad compared to some other factory mufflers!

 

[KMB]

Four Paws,

Thank you very much for your suggestion! I had given up on anybody offering some tips. I like your idea, except I think I'd leave the front cover as is. Adding to your idea, I was also thinking of putting another hole and a pipe below the existing pipe out the side. What do you think? I don't/can't weld, so I'd have to find someone who would have the appropiate pipe and welding ability. Gonna be fun trying to cut the tube out of the muffler. I might try and get a spare muffler in case I mess this one up.

And nice job with the visual description to compliment what you were describing.

Kevin

 

[Four Paws]

Just go slow and take your time cutting that pipe out. Should be easy with a small cut-off wheel on a dremel, small die grinder, etc. I would not add another pipe at the moment. See how it does after you mod it. It is easier to add another pipe later, than take it too far and repair your mistakes!

 

[sawinredneck]

Two thoughts KMB, leave the front cover alone and add another pipe on the other side? NWCS, WHS and othes will mod you're muffler for around $35 if you can be without it for a week or two. Another is Walkers sells pre-modded mfflers that seem to be vey nicely done. Check with the AS sponsers first please!
Andy

 

[KMB]

Two thoughts KMB, leave the front cover alone and add another pipe on the other side? NWCS, WHS and othes will mod you're muffler for around $35 if you can be without it for a week or two. Another is Walkers sells pre-modded mfflers that seem to be vey nicely done. Check with the AS sponsers first please!
Andy

Thanks for the suggestion. A pipe on the other side won't work cause the top cover covers that side of the muffler. I was already thinking about NWCS and WHS for the adding-a-pipe part of my muffler mod consideration. The holes in the baffle will be easy enough. I'm wondering why they (the designers) had the exhaust gases deflect off the front cover into the pipe. Hmmmm. I don't want to open it so much that I run out of carb adjustment (trying to richen it). Does anybody know if that is possible?

Kevin

 

[rahtreelimbs]

If you have the tools I would try it yourself. You know exactly what will clear and what won't. Plus you'll have the satisfaction of doing it yourself!

 

[KMB]

If you have the tools I would try it yourself. You know exactly what will clear and what won't. Plus you'll have the satisfaction of doing it yourself!

Agree.

Just go slow and take your time cutting that pipe out. Should be easy with a small cut-off wheel on a dremel, small die grinder, etc. I would not add another pipe at the moment. See how it does after you mod it. It is easier to add another pipe later, than take it too far and repair your mistakes!

Also agree. Step at a time.

Kevin

 

[Four Paws]

The holes in the baffle will be easy enough. I'm wondering why they (the designers) had the exhaust gases deflect off the front cover into the pipe. Hmmmm. I don't want to open it so much that I run out of carb adjustment (trying to richen it). Does anybody know if that is possible?
Kevin

Like I said, this design is simply to make a 'torturous path' for the exhaust gasses - this quiets it down a bit. Think of a car exhaust - ever had a chance to look at a muffler that has been sectioned open? Full of baffles - this does nothing more than create restrictions and quiet the sound down. Open headers = LOUD but generally better performance - look at Nascar - no mufflers on those cars.

Yes, you can go too far and end up hurting your saws performance. I would drill out that baffle - put it back together and run it like that. Then, if you want more, cut off the piece in the picture I posted, but leave the elbow sticking out of the muffler - put it back together and run it. If you then feel like you need more, proceed as you feel necessary!