I have a Suzuki DT 15hp...throttling is fine at halfway mark(slow)..from halfway mark to full throttle it?

flutters. can only get it to go 5 ot 10 mph. Do you know the reason for this? ..S.D. CA....its on a boston whaler.I have a Suzuki DT 15hp...throttling is fine at halfway mark(slow)..from halfway mark to full throttle it?
Might have a fuel or carby issue. If you get the service manual it will describe any fail-safe situation and likely action, as different makers use different techniques to protect the engine from overheat or low oil.



Failing that drain the tank and make sure it is clean. Re-fill will clean fuel, make sure the tank vent is open, make sure the plugs each end of the fuel line, the primer bulb and the fuel line itself is in good order. Substitute if not confident. drain carby and remove bowl to check no rubbish in carby. Replace in-line filter if fitted, clean and check fuel pump as per manual. At this time you could also tear down and clean the carby and replace any worn items like needle and seat. Gaskets in less than good condition should be replaced. Check float level per manual. Reassemble and check all connections and timings per the manual. Prime engine as instructed in the service manual and test.



When you have fully eliminated the fuel system you must start with the electrical system. Do not forget the cooling system. All these issues are covered in the service manual, there is no way of efficiently covering all the procedures without one, unless you like wasting time and money in a series of random actions that might fluke the repair - or might not.



Good luck.