40 HP over-rev

[BLJC27]

I have a 1997 evinrude 40 hp m/n e40ttleuc. I just bought this boat. This is on a 1989 tracker pro 17 alum boat. When I have it at about 3/4 throttle the tac is running at 5500 RPM if I go any farther with the throttle, it kinda shuts down and won't run right until you turn off the key and restart, then its back to normal until you hit the high RPM's again. I know your not supposed to go over 5500 RPMs but the motor seems to have more power than that. I am getting about 24mph and I think that I should get atleast 28-30 mph??? Do you think that I should go with a different prop? the one that is on there now is 12-1/2x15. Would changing the prop give me more speed without worring about over reving it? Or, do you think I have some other problem. Like I said, it runs good up to 5500 rpm, just seems like the motor has more power that I can't get to.

thanks for the help

 

[nwcove]

Re: 40 HP over-rev

it kinda sounds like a spun prop hub, but maybe not. is there anything mounted on the hull that could be putting air under it? is the motor to high? post some pics of how its all set up, im sure that the problem can be worked out.....even if you do need more prop.

 

[BLJC27]

Re: 40 HP over-rev

Would it still run that speed with a spun prop hub? There isn't anything mounted to the hull. I'll try to get some pictures tomorrow and figure out how to post them to see if you find anything that looks out of the ordinary. This is my first remote steer boat, so i'm not sure that I could tell if something didn't look exactly right.
thanks again