Doughter's 2013 Kisbee is now obsolete and will be sold as soon as I get it functioning. I changed new parts to the variator and clutch last autumn after the old ones were broken and this engine problem occurred right after that. Engine fires OK and the idle and slow revs are fine, but the max velocity with it is about 20 km/h. My guess is that it gets too much air because of the air filter box is not tight enough. The box has been opened so many times that screws are spinning loose when tightening. I tried to fix them with hot glue but no success. How sensitive these are with the amount of air? One option is to find another air filter casing but does anyone has any tips what else can cause the problem?
Air leak around inlet manifold ? Rubber O rings perish between manifold and head/carb. Diaphram in carb goes hard and valve clearance. My favourate !
