Have been having problem with the buggy when at stand still it sounds as tho the accelerator is engaged (revving slightly higher than normal) when i do engage accelerator and rev it the engine goes back to normal idle??What can i do to try and fix??:cry

Check for air leaks and also slop in the main shaft of the Pict carb I am guessing that it has on it.
Sounds like the cause

Also check that the throttle return spring is still ok and doesn't need replacing.

Sometimes the throttle cable can be the problem also if it is sticking.