[sphill]

I hear from time to time on here about "jetting" an ATV. What exactly is jetting?

 

[TRX2fiveO]

Jetting is refered to changing the main and slow jet sizes in the carb. You only need to do this if you alter the engine in anyway from it's stock performance. If you add an aftermarket exhaust, fitler or piston (higher compression) you need to compensate the air/fuel ratio by increasing the jet sizes. Or if you move to a location that is higher than 3000ft above sea level.

 

[sphill]

Well i'm out...I have EFI.

 

[Helmut]

Well i'm out...I have EFI.

In your case, you would need an EFI programmer/optimizer. That is the EFI equivalent of jetting a carb.

 

[Redracer]

Agreed, your EFI machine will self-adjust for elevation but if you ever upgrade your exhaust or intake you will have to buy a fuel programmer.