Full Throttle Blues HELP Please..

[dmizzoni]

I have a 1978 Mercury 1150. It is on a 17 Ft. Tri Hull (Fiberform) I am getting a lot of spray up that back of the transom and am curious if this is reducing my speed, and what may be causing the drag. All Transducers have been lifted up as well??? Also, when I put the hammer down on, when I get all the way to full throttle and try to push the lever down as far as it will go, instead of giving me more RPM's, it feels like she is actually slows down a bit and my RPM's go down a little. Why doesn't that extra play in the throttle at the very end make me go at a higher RPM. I am only getting about 4500 and should be at about 5500. ANy help would be appreciated. Sorry this is so long...so many questions.

 

[Fouled Plug]

Re: Full Throttle Blues HELP Please..

Check the mounting height of the motor. It may be too low in the water, creating the spray you mentioned. The throttle travel may be linkage-related. WOT should have the carb butterflies near horizontal, too much travel will start to close them. Has the boat always hit 4500 at WOT? Could be you need a different pitch prop. Just a few thoughts...

 

[Moving Target]

Re: Full Throttle Blues HELP Please..

Is it slow out of the hole? Might be over propped. What size x pich is it? <br /><br />Do you have a manual? If not, get one and check all your throt/shift linkages.

 

[dmizzoni]

Re: Full Throttle Blues HELP Please..

Thanks Fouled Plug. There is a small board the prev. owner put between the motor and the transom to lift it up a bit. How would I beable to tell it I should raise it more (besides the spray). Is there something on the L/U I should make sure lines up with a certain point on the hull? Cavitation plate for example? Also, if I do need to lift the motor, what is the best thing to use? Maybe a bigger piece of wood? Some kind of wedge? Thanks again!

 

[dmizzoni]

Re: Full Throttle Blues HELP Please..

Moving Target,<br /><br />the pitch is 17. It is slow out of hole and I am only getting about 32 miles an hour on a good day. If I could get my RPM's up, to 55 or so, maybe that would get me going a few miles an hour faster. Any recommendations?