WHAT IF I DONT CHANGE THE MAIN JET WHEN I GO FROM A 3000 AND LOWER ALTITUDE TO ABOUT A 4500 ALTITUDE? I HAVE A DYNO JET KIT AND IM PUTTING THE MAIN NEEDLE JET FROM 3000FT AND LOWER. WILL THERE BE COSTLY CONSEQUENCES PLEASE HELP. THANKS

 

You will run a little rich. It won't kill your motor or anything. Worst case scenerio it will bog. The air is thinner the higher you go.

 

We run our z400 from sea level to about 5500' feet with no problems[img]i/expressions/face-icon-small-smile.gif[/img] If it does effect your motor, just be prepared for a little lag time in the response you get from the engine.

 

We ride everything from BELOW SEA LEVEL, to over 10,000'. Here is my solution to the problem of rejets for altitude changes:

http://forums.atvconnection.com/mess...word1=ALTITUDE

There is no harm in running rich, except that it reduces performance and may foul your spark plug.

 

Doesn't the Z-400 have a CV carb????? If it does you shouldn't have to touch the jets.