My 1980 850 Merc outboard boggs out when full throttle is applied. I have had the mercontrol apart and believe it is together properly. The only way the boat will move in the water is when the throttle is full fwd and the warm-up lever is about half way up, even then it only goes about 5mph. When I test it on shore and put the throttle full fwd it appears to rev out properly but under load it does not. I put fresh gas in, plugs seem good, checked the full throttle stop, all ok. Any sugesstions??
