Stock Exhaust?

[hall1012]

I've got an 07 YZ450F with the stock exhaust set up with the Pro Moto Billet Spark Arrestor and 96db end cap when needed. I also have the 48/170/GYTR fuel screw combo, 50 tooth sprocket, Twin Air Power Flow Kit, and GYTR Off Road Flywheel. I was thinking of putting a new exhaust on my bike, but I was wondering how bad the stock exhaust really is. Since I've made these improvements the bike already has more than enough power, so would a slip-on exhaust really make a huge difference, given the power improvements I've made already? Is that extra 3 or so hp worth the $$$ even though the bike already has more power than I need?

[MikeDD]

I think you would be very lucky to get 3 hp out of a slip on. The exhaust on the 07's is already pretty good and your really not going to get much more power out of an aftermarket one, just a different hp/torque curve.

[WB450]

Funny I also have th PMB end cap on stock exhaust, I saved the exhaust money and had carb work done. The bike is already very fast, save the money.

[grayracer513]

I think you would be very lucky to get 3 hp out of a slip on. The exhaust on the 07's is already pretty good and your really not going to get much more power out of an aftermarket one, just a different hp/torque curve.

You should be tickled to get more than two HP out of any complete system, judging by all the dyno runs I've seen. Yamahas since '01 have always had very good exhausts on them.

Slip-ons fall into 4 categories:

> Quieter than stock

> Spark Arrested

> Very Small Power improvements with huge increases in noise

> Bling

[Ranger18]

I noticed an increase in power with a new exhaust, but I also ordered a system that would alter the powerband to give me more low end hit. It sounds like you ride trails, and most exhausts are going to be louder then stock, the few that are quiter are not going to give you much performance gain, if any. So if you want a track bike consider getting an exaust. If you want a trail bike, I would stick with what you've got. My $.02

[NorCal]

Don't waste your money. I have an 06 450 with an 07 muffler w/ pro moto billet sparky. It is quieter and I have the exact same power as my brother's 06 YZ450 with an FMF slip on.

[hall1012]

Thanks for the input. That is VERY helpful, because you have all convinced me to keep my wallet fatter.

[Idaho_Stas]

I didn't think buying aftermarket exhausts were an option any more. I thought we all had to buy a Leatt Neck Brace instead.

(Sorry... couldn't resist)