nytro exhaust problems

[greenmachine93]

i was out ridin today on my 08 nytro when all the sudden it seemed like it started runnin rough. when i came to a stop the sled cut out. i look at my silencer and there was a 4in hole right through the bottom of it. im assuming that is what caused it to run rough but i just wanted to make sure. cause ive had a hole in my truck muffler before but that never ran bad. i had to drive it 2 miles to the closest parking lot and the faster i went the better it ran, im guessing just cause of back pressure....
thanks for input

 

[canoehead]

In the case of the 4 stroke, the desire is to eliminate ALL the burned gasses from the cylinder when the piston gets to TDC - so the more back pressure, the higher the pressure will be inside the cylinder, and the less exhaust gas we will be able to expel. We don’t want those gasses inside the cylinder, so we want the back pressure on a 4 stroke to be as low as possible. Here’s a decent discussion on 4 strokes:
http://auto.howstuffworks.com/question172.htm

 

[grizztracks]

Any change in exhaust flow can change engine performance. A free flowing exhaust on a 4-stroke typically will result in a loss in low end torque. 4 stroke engines are designed so that the intake and exhaust valves overlap (both partially open at the same time). When the exhausts gasses exit the cylinder a vacuum is created and just before the piston reaches TDC on the exhaust stroke the intake valve starts to open utilizing the vacuum to aid in pulling in a fresh intake charge. A combustion engine is basically an air pump and any changes to the intake or exhaust will change how efficient it pumps air.

I recently purchased a new Harley Street Glide and found the exhaust to be to quiet so I cut out the muffler baffles. The bike was definitely louder without the baffles but the downside was that I immediately noticed a drastic decrease in low end torque. I've since made additional changes to the exhaust and I'm quickly finding out just how hard it is to get the sound I want without losing performance.

 

[canoehead]

Grizz you're going to need a Vance & Hines fuel Pac

 

[grizztracks]

Grizz you're going to need a Vance & Hines fuel Pac

Have one!

 

[yamalover93]

So I've read a lot about the exhaust and icing problem I was just wondering if you put a silencer or different exhaust in it does it make a difference from the stock muffler?