The Lori-K gets a new motor

[SBH2OMan]

Update from a decent trial yesterday...

The motor has been raised up two holes and the A/V plate is skimming just below the water while she is up on plane, so I'm fairly confident that we are at a good starting point for prop selection. With the motor trimmed level to the water (eyeballing it), the prop tends to blow out in turns and on-and-off with the swell. Tucking the motor down solves the problem and does not seem to affect speed or RPM. Unfortunately we don't have the fuel management installed yet, so I can't be definitive about effects. Hopefully within the next couple of weeks we'll receive the new Raymarine e7 and hooking it up won't be too much of a hassle to the NMEA cable from the Honda.

The Honda accelerates really well with the smaller prop, but the stern really squats a lot more than with the old OX66 motor. The thicker lower unit also makes the steering much more responsive both at low and high speeds, but particularly for low speeds. High-speed turns don't seem to be as sharp as with the OX66, however; they seem more gentle and sweeping as opposed to scary sharp.

Hole shot is very good with the 13p prop, as you might imagine. Trimming the motor up and giving her full tabs makes a big difference in getting up to plane, which on our boat really doesn't happen until about 20 mph. The limited trial I did with the Titan 15p put her at about 26 mph at 4400 and about 39 at 5500. 26 mph @ 4400 seems a lot more usable to me, but I really didn't like the time it took to get up out of the hole with the 15, and the motor definitely felt more like it was struggling.

I wish I had some other props to test...

One issue that seems concerning is how the motor gets buried in the water behind the boat at low speeds. While "plowing" at around 8 to 10 mph, the stern squats badly and the motor hunkers down into the water as you can see in these pictures. Apparently Honda's have much better cowl seals than many other outboards, but it still freaks me out a bit...

 

[SBH2OMan]

Update on an old thread... Still running the 13" Solas prop, but now I finally got the fuel management system up and running. I gave up waiting for Raymarine to release the update to the e7 that would support MPG, so I installed an LMF-200 gauge along with an EP-65R and EP-85R (storage and level sensors from Lowrance).

Bottom line, I now know that I'm getting 2.4 mpg while running at 25 mph (SOG) in moderate seas running up hill with the motor trimmed at 60% and the trim tabs pretty much buried.

In calm seas, I touch 2.8 mpg (using SOG) with the motor trimmed way up (like 70%). BTW, when I eyeball the motor sitting in the slip, it appears that the Permatrim is level with the bottom of the boat when the motor is at about 65% (should it be 50%?).

Not sure what my next step should be - trying a different prop or fiddling with the running angle of the engine. I'm still confused about the "reversing a set of negative wedges" comment, as well as Dale's suggestion to check the trim limiter rod (is this something I can do myself while the boat is in the water?). I'd really like to get this engine sitting right before I start fiddling with props...

 

[DaleH]

WEDGES alter the angle of the OB mount braket, so you can dial in more effective TRIM Down or up. I sat 'trim' as that is the limited range where the OB hydraulic trim/tilt motor can effectively move the motor while under power. Once the t/t system hits the limit of the trim range, it can only tilt when power is NOT applied, i.e., can move the motor against gravity and it's own weight only.

Example, if your transom angle or OB bracket angle was too steep (out AWAY from hull) then you'd be extremely limited in as far as how much you could trim the motor up, as soooooooo much of the range would be already used just to get the OB straight up and down. That is where someone opined transom wedged would work. They are angled, the thicked wedge would be to the bottom mount holes, to push the LU of the motor out and away from the hull.

TRIM/TILT limiter ... most OBs only have a tilt limit and since those don't apply during power mode, the other poster was spot on, i.e., if you needed more trim range and the motor can't develop it, then you may need wedges.

You can't tell by a tell at rest. You must have someone else steer and you go look over the stern. Your motor, if anything, should be tipped with the lower unit end out a little more than straight up. Perpendicular thrust to the boat's movement is the theoretical ideal, but ignore the fact the OB LUs create drag and sometime trimming the LU out more can reduce drag and create significant more efficiency in miles-per-gallon, and NOT necessarily any increase in speed.

Your OB cavitation or ventilation plate should ideally be at or above the surface of the water.

Offhand, but I find Solas props to be crap, I'd go for a 3-blade Merc Mirage or 4-blade Powertech offshore, maybe a 4-blade Merc Rev4, if made for Honda. Contact Ken at www.propgods.com