ORIGINAL: Tree1
looks like it has the NX-26 engine. If you are not going to replace the engine I would recommend sealing the engine with automotive silicon around the carb and backplate. Also I would remove the needles and check the o rings. If the are ok then put a little plumbers tape around the threads and reinstall both needles.
i used some Permatex Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker (a little copy/paste action there) on my magnum nx-18 engine. When it came to the carb I left the smaller o-ring in place, but removed the larger one that seals against the outside edge of the crank case. Then I applied a film of silicone on the body of the carb, tightened the lock nut, and let it sit for a day. Probably was a bad idea to remove the upper o-ring because the carb would rock back and forth easily when the throttle and brake was applied. So when using the sealer are you supposed to use new o-rings as well? No matter how tight the carb lock nut was it would still wiggle so the seal from the silicone was basically worthless. I guess other engines are designed so the sealing o-rings can seal instead of hold the rocking motion of the carb in check too?