Just going over carb stuff for my 83 resto and noticed the different main jet...

Just going over carb stuff for my '83 resto and noticed the different main jet between 83 and 84-85. Anyone know why or if I should whack a 260 main in my 83?

  • The Aussie 84/85 models were restricted to meet ADRs. I'm not sure if the much larger main jet was a way to quieten them down, or it was what the restricted motor needed to run.

    I would be surprised is your bike still had restrictors or the crazy jetting all these years later.

  • I stripped mine down and I have the 135 main but a 30 pilot. I was wondering if the bigger main would be better or make it worse.

  • 30/135 sounds perfectly reasonable. If it runs well, then leave it alone!

  • The bigger main will definitely make it run like a bucket of pus.

  • I know the 83' runs the 175 case. Maybe thats why

  • Despite what has been published in various places, the KDX200 motor was significantly different to the KDX175 and every model of KX125 motor.

    All of the KDX200 motors 83-05 are built on the same basic architecture, despite the obvious differences - the "grandfather's axe" basically.

    The main differences between an 83 and an 84/85 are:

    1. More piston-bore clearance;

    2. Larger output shaft on the gearbox;

    3. Different shifter mechanism.

    The parts list for the US 1984 model shows 35P/135M as stock, which shows that the big main jet is part of Aussie ADR compliance.

  • It could be that the older model ran an R (reverse) style jet. Different numbering system. OEM Parts list shows that the 135 was indeed an R jet which has a much larger hole in it than a regular 135 jet would have.