Not enough info. There are too many other variables. Speed of a boat is dependent on boat length, whether it is a planning hull, what size and pitch propeller does it have, and weight of the boat. So it is impossible to answer this based only on the size of the engine.
50 mph
30cc is equilent to 20 mph
15-18 mph on full
In MPH, which Miles Per Hour.
The minimum speed of 6v motor to produce electricity is 15 Mph.
What mph compare to a 3.3 horse power outboard motor
i have a whole new tune up in motor 37.000 miles on motor
55-70 mph
About 240 MPH
if you get it from a hobby store it should go from like between 15 to around 20 mph on a stock motor if you get a brushless motor it can go at least 30 mph or faster
Well, it just depends on their displacement, or cc. I don't know what the average motor scooter displaces, so I will just give average top speeds based on engine size. 50 cc: 38 mph 80 cc: 45 mph 100 cc: 50 mph 110 cc: 50+mph 125 cc: 55 mph 150 cc:60+mph 180 cc: 68-70 mph 200 cc: 72 mph 250 cc: 75-80 mph 300 cc: 85+mph 400 cc: 100+mph 600 cc: 115+mph 650 cc: 125+mph 800 cc: Over 135 mph
You probably have the wrong type of fuel.