hey tonight i took off my spark arrestor on my 400 and made a new tip with staniless with about an 1 1/4 whole in it. it is a little lounder than stock and sounds a lot better. I can't feel any power gains but i have not rejetted. so i think it is running lean. I was just wondering if anyone has done this or heard of it done.

 

I have seen people take off the spark arrester on there stock exhaust and i think it sounds horrible. I dont understand why any one that can afford a $5700 quad cant afford to spend 200-300 dollars on a good slip on exhaust. It not only sounds and smells better it looks cleaner. Just my personal opinion i guess...

 

I made one for mine out of aluminum that looks nearly identical to the stock one. Have one on my Son's 250EX too! And you're right, you'll need to re-jet as the better flow leans 'em out a little.

 

If you want info on how to make your stock pipe flow better, go here. For pictures of a simular setup go here.

 

yea i've done to my honda before i got my exhaust and it does increase horsepower but it reduces back pressure on ur valves.

 

Yea, but back pressure on your valves isn't good for anything