You bet it does! I've found that out on my Polaris. With a slightly stretched belt I lost 10 mph top end. I was getting smoked by SP HO's. After a new belt, I was back spanking them on the straight away. Although now, with the 650, even with 27's I have no problems with the HO's. [img]i/expressions/face-icon-small-smile.gif[/img] [img]i/expressions/face-icon-small-smile.gif[/img]

 

Check your jetting. I got beat by a stock griz here a couple weeks ago. Then went and changed my jetting about 50 times and finally got it dialed in. If your running a dyno jet kit the jetting is probably rich. Their kit is off. After getting the jetting right was running neck and neck with the stock griz. Then i found another problem. My throttle wasnt opening all the way. I adjusted the throttle cable at the handle bars and gained 4mph on the top end and am now eating griz like he was stopped. Everyone check your throttle! When the machine is off hit the throttle wide open. you should here a click when wide open and another click when you let off the throttle. If you dont hear a click when it is in the wide open position the throttle cable has stretched and needs to be adjusted. After adjusting make sure it clicks when you let off to make sure its not adjusted too tight. Try it youd be suprised the difference it made in mine.

 

mtecate4g,
Thanks for the tip about the throttle cable. What elevation are you at and what are your jet settings?

 

I am not sure what but elevation is but its under 1000feet for sure. I am running 132-136 dyno jet jets needle on the 4th clip My sig says a yoshi exhaust but i have recently switched to a HMF. I have 12 3/8 holes in the air box lid with the bigger snorkle. I am also running an EPI Clutch springs red and black. Mine will pull about 67mph. And it gets there fast. Well now any way that i fixed my jetting and throttle.