Good compression, rebuilt carb, new plugs, fresh fuel. Runs fine on hose. When put in the water it will idle & fast idle but trying to accelerate will stall out. Any suggestion...
It could be running on one cylinder. A motor of that size will start, idle, and idle fast on one cylinder but when given some throttle, will shut down. If you have an induction timing light, hook it up to the plug wires and it'll show you which cylinder is not firing (or firing intermittantly). It could also be a fuel/air leak around one of your carbs. Sometimes that's hard to isolate.
Check for spark with spark tester from local auto parts. About $6 bucks. It should jump a 3/8" to 7/16" gap with no problem. But you say it stalls upon acceleration. Pull plugs and see if plugs and see if one or? running rich, lean or normal. That would tell you what cylinder is having issues.
