RE: MVVS 58 HIGH IDLE
The idle mixture probably is too rich, which forces you to have the throttle too wide open for a reliable idle.
with the engine warmed up, find the idle needle setting that gives best rpm at a few clicks open, and open the L needle 1/4 turn from that setting.
Proceed with the H-needle and tune for best rpm. Open up to the verge of loosing rpm.
Check throttle response. The engine should react well to a quiet throttle application, and slightly lag when you horse the throttle.
Add some servo speed delay in your TX if possible. If not, either learn to throttle up controlled, or slight open up the low needle.
If with these settings the problem persists, suspect air leaks somewhere between throttle valve and piston. (gaskets, front seal, cracked case etc.