How do you tell the diff between a 125 jet and other jets?

I need to know this asap.

I'm racing a sang tomorrow that has a 165 shot and a 125 shot.

He says he will just run the 125 shot with me.

Is there a way of checking on this?

How would I confirm by examaning his motor if its a 125 or 165?

He has a Zex kit.

Are they color coded or do they have engravings?

Jet sizes are engraved or stamped onto the jets themselves. But he'll have to disconnect the lines leading to the nozzle to show you what jets he is running. A nitrous jet of around 51 will be 125 horse, and around 60 will be 165 horse. Hope that helps.

Maybe Zex runs different jet sizes, but a NX 125-shot on the LT1/LS1 is a 57N/31-33F.

Originally posted by JSK333
Maybe Zex runs different jet sizes, but a NX 125-shot on the LT1/LS1 is a 57N/31-33F.

Those jet sizes are based on the nitrous manufacturers recommended bottle pressure (usually 1000 psi), and the specific vehicles fuel pressure. So....they usually vary from kit to kit. But don't let the guy you're racing tell you that a 125 shot has a sixty-something nitrous jet...;)