:devil: I have a 2000 mxz 600. the snowmobile runs great!
the only problem is that Its very hard to keep up with my buddies in the
mountains. I have no problem when the snow is a little packed down, but
It sinks like a rock in the powder.
I know its a mxz and has a 121 track,(should have bought a summit!!)
I have a 121X1.125 on it, I want to turn it into a 136X1.5
i went on tracks usa to look for a kit, but it seems you have to
buy it all seperatly. Oh yeah..... what the heck is a hyfax?
and what do I need to make this conversion work properly?

A hyfax is the plastic strip that runs at the bottom of your suspension rails. its used to reduce the friction between the track and the metal rails... I'm curious to how much mountain riding you do... these days a 136 x 1.5 isn't much for powder

oh and you'll need a rail extension to go from a 121 to 136 but if you decide to go bigger its almost a better idea just to get a whole new suspension

I have a 2001 mxzx 600 that I put a 136x1.5 on and I love it. It gets me where I want to go. All you need is a tunnel extension, rail extensions and new hyfax, and of course the spendy part the new track. Its a pretty easy job. I know it made a big big difference in my sled. Hope you enjoy the change as much as I do.

Ohhh. I guess hyfax is just a fancy-dancy word for slider.
I dont do that much mountain riding (2-3 times a season)
which is why I only want a 136.
I just need to know the details... I know i need rail extenders
and to drop a tooth on the small gear. do I need to add another
bogy?

I have a MXZx800 converted to a 144x2. I purchased most of my things through Tracks USA. This is what I did:

Rail extension
New track
tunnel extension
new bumper
new gears and chain (use the same as a summit 600)
new sliders/hyfax

I did all of this for just under $700.

When you go with a bigger lug, purchase some ice scratchers to assist with cooling down the engine. The bigger lugs tend to cause the motor to overheat in less than perfect snow conditions.