Main Jet Kit 124-134 (10 pc)

Jets for the Rotax Max Dellorto carburettor.

The following jets are included in the kit:

124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134

Here are some standard recommendations

Rotax Max Junior/Senior Evo

18 degrees and warmer: jet 122

Colder than 18 degrees: jet 125

Colder than 10 degrees: 128

Our experience is that there is barely any difference in jet size between the Rotax Max Junior and the Rotax Max Senior.

Rotax Max DD2 Evo

18 degrees and warmer: jet 130

Colder than 18 degrees: jet 132

Colder than 10 degrees: 135

Effect of the needle

You can fine-tune the response slightly by raising and lowering the needle position, i.e. the throttle needle that goes down into the jet.

The higher the needle, the more fuel it gets on throttle application, and the lower the needle, the less fuel. What can be a bit confusing here is that position 1 on the needle's clip gives less fuel, and position 5 on the needle gives more fuel.

Once you've found the right jet, this is where we do most of the work to fine-tune the engine's character.

Rotax has an app for Android and iPhone that helps you find the right setting. The app should be treated as a recommendation, and you should then experiment yourself to find the right feel for you.

iPhone:

https://apps.apple.com/se/app/rotax-max-jetting-guide/id1152315347

Android:

https://play.google.com/store/apps/details?id=com.carburetorjetting.calculator&hl=en_US

• rotax max jetting guide - user manual.pdf