I just purchased a used 06 800 sportsman and the original owner had the 2nd muffler removed, patched the hole left in the first muffler and then drilled out the baffle inside it to reduce the back pressure. Has anyone done this and would this mod make any difference or be bad for the engine?

 

It shouldnt hurt, could get an aftermarket silencer...

 

I rode it after my last post and it seems to stutter a bit, only noticed it in low range but almost like little backfires but without the bang. Wondering if its because of the lack off proper back pressure. Any ideas?

 

Interesting. Well, I would think that this would be ok. If you look at the 07 800s, the base model is a single exhaust machine and the deluxe has dual exhaust. I'm mighty curious as to why he did away with the 2nd exhaust, but I don't think you get a performance gain from it. Keep in mind the 800s sound a bit different as a rule. You could go look at a 07 base model and kind of stare and compare.

The sucky thing though is he may have voided the warranty by doing all this. Thats of course speculation. I don't know. If it were me, I would take it in to the shop and have them add it back. It looks cool....and you can put your mind at ease.

If it is backfiring, that could very well just be a fouled plug. Which would be real easy to take care of. Had a friend with a similar problem on a seperate machine (back firing) and he had flooded the engine with gas quite a few times. Change the plug and no more back fire. He had actual real POP though.

Since it's used, it might be a good idea to have it serviced anyway because you never know what the previous owner did or did not do.

 

Is it possible that you are hitting the rev limiter in low range. Does it miss under hard exceleration.