I'm at the end of my anchor rope

[ATF27]

I'm at the end of my anchor rope

Well I've posted a few times about trying to get my boat and motor running better but the more I learn the more confused I get.<br />I can't get better than 5300rpm on my 2001 150hp optimax on a 19ft deep V Fisher aluminum walleye boat. Weight=1800lbs<br />This after playing with about a half dozen props.<br />My question is "How does raising or lowering the motor mount height affect performance"?<br />Everone says the cav. plate should be even with the bottom of the boat but are we talking the very bottom of the V? Mines about 1.5-2 inches higher. Should I be lowering the motor instead?<br />And to top it all off I had a mechanic tell me its because the boats welded and is being slowed down by friction.<br />Riveted boats are much faster he says.<br />Can anyone explain this in terms a dummy can understand and then get him to explain it to me???

 

[imported_JD__]

Re: I'm at the end of my anchor rope

Re: I'm at the end of my anchor rope

ATF27,<br />Your lower unit creates a certain amount of drag. By raising the engine there is less lower end in the water, lessening the drag or resistance.<br />My Tracker Avalanche has an all weld construction. If I squat down and sight along the bottom of the hull (looking from rear to front) I can see a series of slight ripples. Thse ripples corespond with the stringers that were welded inside the hull. This will slow you down. Any blemish, bump or irregularity will. To say rivet heads create less drag than welds? I don't know. I'd say it was more dependent upon the manufacturers tolerences and quality control.

 

[Dhadley]

Re: I'm at the end of my anchor rope

Re: I'm at the end of my anchor rope

Engine height largely depends on prop technology. Where youre at is not uncommon. As far as the rpms go, if youve tried several props of different pitches and see no change in rpm then the motor is regulating rpms. <br /><br />Its not uncommon with these engines to see them gain rpm after a certian period of run time unlike a carb'd motor. Some of these newer motors stay in break-in mode for 20 hours.

 

[Tufan]

Re: I'm at the end of my anchor rope

Re: I'm at the end of my anchor rope

Did you try triming it?<br />After you get it on plane, engine usually gains more rpm and speed. If nothing helps I'd try trim tabs.

 

[mrtool2u]

Re: I'm at the end of my anchor rope

Re: I'm at the end of my anchor rope

I am running a older 19 foot aluminum boat(120 Johnson) and I have been told by another guy that a riveted boat is much slower,,,and I can deffinetly believe that.(check post,,Do I need a jackplate,,under general outboard ) I have played with a few props,,and the Stiletto gave me the best performance,,with the Ballistic being 2nd.What kind of speed are you running.

 

[ATF27]

Re: I'm at the end of my anchor rope

Re: I'm at the end of my anchor rope

I did trim up as far as I could I guess. Is the trim limited somehow while the engine is running? can only trim up to a certain point then it doesn't go any higher at all.<br />What are trim tabs? Do they work well?