Bogging out makes a BU BU BU BU noise and the buggy will barely move, normally followed by a stall. The manual says 38,000 but I dont believe that as there are too many variables. closer to 30K I think.

Also if when leaning out the HSN you start to cut out at WOT (Wide Open Throttle) then richen the HSN a 1/4 turn and leave it there. Try to let the engine warm up whenever you start it as ragging it on the box is not good.

The best mod for these engines is a boost bottle. It will need a starter box once fitted but then you get the full potential of this mill and less problems caused by the Pullstart assemby.