I am trying to adjust the midrange on this MVVS 1.6 gas engine (redhead)-it seems to be four stroking at 1/2 throttle, it has a great idle, great top end (swinging a 18X8 @ 7200 rpm) pulling a 80 inch GP chipmunk-what do you think I need to do-thanks in advance-I found the mvvs engine being discussed but got tired after reading 10 pages and not finding what I need-