Hi

First of all apologies for such a basic question but I’m brand new to this.

I have a second hand 2003 RM85SW. Reading the instruction manual and looking at the carburettor I am not sure which screws are used to adjust the fuel air mix.

There are two screws, one on the left and one in the middle of the right hand side of the carb body. The middle one has a spring in it.

The instruction manual calls the middle one a throttle stop screw. And the left hand one the air screw.

The left screw is screwed all the way in to the body of the carb, unscrewing it makes no difference to anything obvious in how the engine runs.

The middle one changes the idle speed (slower when screwed out to the left, faster when screwed in to the right).

My question is should the I be using both screws to adjust the jetting and air balance? Does the left screw do anything? I’m confused!

Thanks in advance for any tips.

Jerry

 

The one on the left is your fuel/air screw and the one in the center is your idle screw. the idle screw cannot be turned all the way in, I would say it needs to be brought out at least one full turn. I need to know why the carb is off in the first place, how was it running before the removal?

https://mudlinemotorsports.com/