something odd going on I think its the motor height

Joined
Feb 17, 2012
Messages
2,906
stratos 16.2 foot with a 86 evinrude 120 hp 4" jack plate fixed and whale tail
prop is stainless 19' pitch

my engine would not rev out but ignoring that the boat ran fine and with 4 people on board (max weight allowed) the boat ran fine and at 4800 rpm it would run 38-40 and it reacted to trim correctly

I found that the carbs were not adjusted so they never opened 100% and I fixed the problem.

Now 3 people on board at 4200 rpm I get 34.5 and can trim correctly at 5500 I get 38mph and I loose the ability to trim the nose up.

another problem I have is the prop has acted like its spun. After slow trolling I go wot and the engine revs (there is restriction so something is moving) but the boat doesn't move. I back off to tick over then go wot again and it takes off fine. theres seems no set pattern to this as it may happen then again another time it does not. Im wondering if exhaust gases are under the whale tail and that's causing mass slip but if that was the case then it should clear the gas in a few seconds and the prop should bite.

Everything is pointing from what I have read to a motor that's mounted to high and as the weight decreased in the boat the boat lifted the motor higher in the water at higher speeds and the prop is breaking the surface. But that really doesn't ans what's going on with the prop acting like its spinning at low speed when I go wot.
 
Joined
Feb 17, 2012
Messages
2,906
Re: something odd going on I think its the motor height

changed prop to my spare I haven't tested yet. The 19 ss shown signs that the inner piece has spun at some point as its looks kinda melted between the rubber and the part with the spline. Dropped the motor 3/4 to 1" (a hole on the outboard mount). Raining real bad so I probably wont get to test till next weekend but any input would be welcome.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: something odd going on I think its the motor height

Occasionally a spun hub will grip again after slipping.Perhaps the friction does soften or melt the rubber and it grips when cooled.
I would consider the hub suspect.
While the whale tail can improve hole shot And may resist venting I think if you check that the angle changes considerably as you trim down or up.I think a test run without the whale tail is a start.
 
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