Just bought a new 2005 grizz 660 and am planning to go trail riding in colorado. Elevation will be around 8 - 10 thousand feet. I dont want to get out there and and have it run doggy. I am up for any suggestions thanks

 

You may only have to remove your air box lid ....It may still run a bit fat but it may run just rite...If you have to jet..I usually go down 4 sizes

 

This works great! Install a couple of TPI Valves in your airbox lid. http://www.thunderproducts.com/tpi_valve.htm

Open them up for more air as you ascend, and close them again as you descend (and above 10,000 ft., just pull the airbox lid completely off). It's an INSTANT REJET!

I have my bikes jetted for the low desert (sea level or even below!), but I also ride up into my local mountains and the Sierras at over 10,000 ft. So, this gives me the go-anywhere versitility that I need.

 

Thanks for the info, sounds easy, but... how do i know what valves to install

 

I use two of the "low boy" valves, on each bike. You gradually open them, little by little, as you go up in altitude, and close them again as you go down. DO NOT forget to close them as you descend! That will make you lean, which is bad for your engine.

 

i would say re jet is the way to go its easy and it will make ur engine run consistant instead of knockin alot