I purchased a used muffler off ebay to play with and received it today. Can anyone tell me from experience some definate do's and don't while I experiment with it? I plan on welding a flange on it so I can open it and make diffrent mod's for my neverending quest for more power.

Thanks, Mud

I'll keep you all posted on my results.

 

have you checked the tech tip section for prairies on nyroc's site.on my 360 I just took the muffler off and drilled a 1/2 inch hole all the way through the inlet and outlet,they are offset.
it's a little louder than my wife's 300 but not bad.

 

I just checked out the nyroc info on exhaust modifications. It was done on a 650 and 700 prairie but I believe I could obtain the same results. I will start on it this morning. I can't wait to see the end results.

Thanks for the tip,
Mud

 

The first test results are in:
I have more mod's to make before I post pictures but here is what I can tell you. I wound up drilling 7 3/8" holes all the way thru the muffler after cutting the back section off. I opted to leave the packing in place for the first test and I also left the stock tail pipe extention on. This modification seemed to make no diffrence in sound what so ever. As far as performance goes, if it did help, it is to small to really tell.

Today, I will remove the packing and enlarge the tail pipe extention. I am hoping this will create a change in sound and performance. I don't want the bike to loud but a nice rumble would be sweet.

More to follow,
Mud

 

I would not waste your time with it, the muffler mod my 02 650 slowed down doing this. I put a hmf slipon on and picked up 5 mph top end I talked with a guy with a dyno and he said it hearts more then it helps, same with hmf they said most times it does not work. just my 2 cents here.

 

Scuffy, I had also heard the same and seen first hand what testing will do on a dyno. That is why I bought a second muffler to play with just in case it hert it more than help. I can always put my stock muffler back on. Growing up my father had a dyno test stand in his race shop and you learn real fast that races are won in the shop not on the strip. Thank you, I do appreciate your input.

Today I removed the packing and enlarged the tail pipe extention. I did obtain a very nice sound for the bike but I still have no idea what it has done to the performance of it. I took it down the street a few times and it still felt strong but I cannot tell if the overall power was better or worse. I had No backfire and it did sound good. I will be taking it back out next week to some hill climbs and mud pit's. I will be able to better test the performance there. Also I have a new plug to install before I go so I can check it after the ride and see if I am now running to lean? I will continue to keep you all posted. For now, the weekend is here and I have to work. So, you all go play hard and ride fast.

Mud

 

OK, here are the test results. After putting the bike through several ride tests I found that the low and mid range were hurt a little on responsivness. Also I did not have hardly any backpressure while going down steep hills. I had to stay on the brakes a little more than I like. The top end had a little more go but because of the style and type of riding that I do. I have elected to go back to the stock muffler. The sound that I achieved was really nice but not worth the loss of low end that I received. I pulled my plug and it was burning fine so I did not have the bike running to lean.

All in all it was a fun test. I will still post pictures of the modification if anyone else want's to experiment like I did. Or if anyone is intrested they can have my experimental muffler for $20.00.

Keep riding and searching for hidden treasures,
Mud