ON a Mvvs 58cc gas engine i have, my problem is, when i put engine at full throttle and leave it there for 45 to 60 seconds or so, all of a sudden the rpms drop by 400 to 500 rpms.
So I slow down the rpms to about idle and then throttle up to full, back and forth ,till I eventually get all rpms back at full throttle.
Normal rpms at full throttle are 6900rpms using a 22 x 10 wood Menz Prop.
Can you help me???