Home Forums TaG Rotax Max FR 125 stalls when taking off Reply To: FR 125 stalls when taking off


EJ Korecky

Did some testing today…started with air screw at 1/2 turn, and went  in half turn increments to 3 turns with no change whatsoever. Tried the needle in clip in every position – no change. Tried leaner pilots – no change. Tried a new battery – no change. Without feathering the throttle at take-off, it stalled every time.

Here is what I noticed – when I removed the atomizer tube (DQ 266), I noticed that it does not really seat on the atomizer bush, or carb body. The outer hex part of the tube just tightens onto the internal threads on the carb body. Without it seating, I am assuming that fuel can just get sucked past the threads into the Venturi – so it makes sense that no matter what I do, it will always be rich on the very bottom. Kinda explains why my mains have always been much leaner than others racing in the same class. I dripped some fuel onto the base of the atomizer when installed and actually watched as fuel dripped thru the threads into the Venturi part of the carb.

Maybe its time to upgrade to the new EVO carb…

Thanks for the ideas and suggestions,