Long read warning.... sorry, I just love this stuff.
I have had my 06' 22 cruiser for about a year and a half now. It is my dreamboat and I am so thankful to have been able to upgrade and modify it to make it even more dreamy. I have added diesel heat, autopilot, lighting, electronics, interior mods, roof rack, windlass, and a ton more. I have had such a blast working on and adventuring in this rig. Recently I had the opportunity to really step things up and turn this into my ultimate dream C-dory with a new repower! I replaced my original, carbureted Honda 90 with a brand new Yamaha 115 SHO VMAX. In addition to the reliability and convenience of a modern motor, I was after increased fuel efficiency/range/economy and the ability to cruise at higher speeds when the conditions allow. Lastly, having the power to go more than like 18mph wide open with 5 or 6 people onboard would be cool. With my 90 I would cruise around 18-20mph at 4500-5000RPM. with this new engine I can get about 28-30mph at the same RPM (surface conditions permitting of course). Wide open, my record speed was 42MPH at 5900ish rpm... way faster than this boat should really go but it's cool to say it can ;-). I was even able to go 38mph pretty easily with 6 adult onboard once! I was also impressed with the new fuel economy, getting about 5.5MPG at 28MPH (I would get between 3.5-4MPG at 18mph with my old honda). I am running a Michigan Wheel Ballistic 13.5x17 prop (not sure that this is the perfect prop but it was working pretty well. It has a pretty racey shape with flat tips and lots of cup).
I was talking about performance with my friend, specifically how the prop felt a little "slippy" on the hole shot and boat would also do some weird, unpredictable "leaning" at speed. He thought it sounded like my motor may have been mounted a little too high on the transom.... long story short... he ended up talking me into getting a hydraulic jack plate. This sounded awesome to me since I often explore very shallow areas and having the ability to tune yet another trim variable for efficiency and performance sounded fun. Im an engineer and love having extra knobs to turn... It's worth noting that I also have electric trim tabs.
I was able to link up with another friend who hooked me up with a great deal on a Bob's Machine Shop hydraulic jack plate. It has 4" setback (lowest setback you can get while still having an integrated pump motor) and 6" of vertical travel. Its powder coated black, looks sick and I even installed a sweet, steering wheel mounted "turn signal style" switch to adjust height. I was super pumped to take it for a spin.
However, after a few trips and a couple hundred miles over the last few weeks, I am disappointed in the performance. AFTER installing jack plate, I seem to have lost about about 4mph on the top end and am back to getting like 3.5-4.5MPG (depending on fuel load). I also dont notice much change in performance based on jack plate position. I have 6" of vertical adjustment centered around cavitation plate being level with bottom of boat (cav plate 3" above or below bottom). Of course, I can bring motor up so high that it cavitates like crazy and my performance drops way off. But just below that point, all the way to full down position, I dont notice much difference in ride, speed/rpm or fuel economy. I can go crazy shallow now with motor trimmed down which is pretty cool!
Another complaint I have is that with this new motor, I no longer have as much bow-down trim capability as I would like. My honda had a permatrim AND a transom shim to give me even more bow down authority. Trimming that motor down plus full tab down would give you a scary amount of bow burying power! Great for running at 10-12mph in heavy ocean wind swell. With my new setup, I am almost always running with full tabs and motor trim down on flat water just to try to cut down on chop slap. Im dying for more bow down authority.
Pics for attention...
Before jack plate but check out the sweet transom brace that I laser engraved with my boat's logo! At this point I was almost done with rigging and ready for the first start!
Ok lets talk causes and solutions:
Issue 1: Poor performance after jackplate install:
Idea 1: The extra 4" of setback puts the weight of my 380lb motor even further back on boat. Not to mention additional ~40lbs of jack plate on transom. This combo is still lighter than many motors (for example, a Suzuki 115 can weight about 420lbs)
I have noticed that these boats seem very sensitive to weight in the transom. With my honda 90, the performance difference with 50 gallons of fuel back there vs. nearly empty tanks is astonishing. Not sure what exactly why, but id much rather have 300lbs worth of people up front than 300lbs of fuel in the back. I have noticed a little trim tab improves efficiency by maybe providing a little extra lift back there. Too much tab however can have the opposite effect.
One idea I had was to consider moving both my batteries way up front. I would probably need some pretty heavy cables to the motor for such a long run though. That would probably pull close to 80lbs off the transom.
Thoughts or experience here?
Idea 2: Maybe the additional setback puts the prop in more turbulent water?
I imagine the further back you get from the point where the water breaks free from the very aft edge of the hull, the more mixed up it becomes. Perhaps, now that my prop sits 4" further back, it's sitting in less "clean" flow? This might reduce efficiency? One common benefit of a jackplate with setback is that you can now run your motor a little higher up since the water has more time to rise after transitioning off the back of the hull before reaching the prop. I was really hoping that running motor high (just before cavitation sets in) that by reducing that amount of lower unit in the water, I would also reduce drag and get better efficiency. At the same time, I was hoping that running the motor extra deep would provide more stability, giving the boat a more planted feel in rough conditions. I dont really notice any of either of those benefits. Just overall worse performance.
Thoughts on this? I think my next step may be to try different props. Perhaps something about adding the jack plate also changed what prop design/size/pitch is ideal. Anything else I should try? Im tempted to remove the jack plate... id hate to because it's just so dang cool haha.
Issue 2: More bow-down trim authority
Like I mentioned earlier, I would REALLY like... no... NEED... more trim authority. These boats really shine when you can engage the V in the bow as chop starts to build. I was spoiled with the permatrim and 5 degree transom wedges. I could almost cause this thing to do a front flip.
Solutions:
1. Moving batteries forward may help some.
2. A prop with less bow lift? My current prop is a Michigan Wheel Ballistic. It has a lot of camber which apparently generates a lot of bow lift. The boat feels skatey and unstable at high speed (again, I realize this isn't a bass boat). I also need about 50% tab down and maybe about the same amount of bow down engine trim to keep from porpoising. This all seems to suggest to me that a prop with less bow lift would be helpful.
3. Bigger trim tabs? I could probably mount larger tabs. It would be great if they could operate off the same actuators. This would give me more bow down and left/right authority. Possibly even a little better efficiency due to more lift off the transom without needing such extreme tab angles?
4. Put a permatrim on my new Yamaha... I hate to do this since this motor is like 2 months old and has the prettiest bass boat sparkle blue paint job... drilling holes in a brand new engine would require several shots of whiskey to build up the courage. I would then be concerned with my ability to accurately place these holes... see the conundrum? However, peramtrims do provide some serious control surface area back there. I also wonder how a peramtrim would impact efficiency. It would add drag. Would this hurt my fuel economy and top end? Any other advantages beyond increased trim authority?
5. I could also add 5 degree wedges to the motor to allow for even more downward motor trim travel. I feel like im getting carried away now though. There would then be wedges and a jackplate between my motor and transom... Have I mentioned that I stay up at night wondering about the added stress on the transom with higher HP motor and the increased leverage from the jack plate? I do have a fairly recently rebuilt Coosa transom but can't speak to the quality of the job since it was commissioned by the previous owner.
Anyways... If you made it this far, thanks for sticking with me. I would love to hear everyone's thoughts and advice. I know there is a ton of wisdom on this site. Anyone else have experience with a jack plate on their 22 cruiser? Any prop recommendations?
Thanks everyone for the help!
I have had my 06' 22 cruiser for about a year and a half now. It is my dreamboat and I am so thankful to have been able to upgrade and modify it to make it even more dreamy. I have added diesel heat, autopilot, lighting, electronics, interior mods, roof rack, windlass, and a ton more. I have had such a blast working on and adventuring in this rig. Recently I had the opportunity to really step things up and turn this into my ultimate dream C-dory with a new repower! I replaced my original, carbureted Honda 90 with a brand new Yamaha 115 SHO VMAX. In addition to the reliability and convenience of a modern motor, I was after increased fuel efficiency/range/economy and the ability to cruise at higher speeds when the conditions allow. Lastly, having the power to go more than like 18mph wide open with 5 or 6 people onboard would be cool. With my 90 I would cruise around 18-20mph at 4500-5000RPM. with this new engine I can get about 28-30mph at the same RPM (surface conditions permitting of course). Wide open, my record speed was 42MPH at 5900ish rpm... way faster than this boat should really go but it's cool to say it can ;-). I was even able to go 38mph pretty easily with 6 adult onboard once! I was also impressed with the new fuel economy, getting about 5.5MPG at 28MPH (I would get between 3.5-4MPG at 18mph with my old honda). I am running a Michigan Wheel Ballistic 13.5x17 prop (not sure that this is the perfect prop but it was working pretty well. It has a pretty racey shape with flat tips and lots of cup).
I was talking about performance with my friend, specifically how the prop felt a little "slippy" on the hole shot and boat would also do some weird, unpredictable "leaning" at speed. He thought it sounded like my motor may have been mounted a little too high on the transom.... long story short... he ended up talking me into getting a hydraulic jack plate. This sounded awesome to me since I often explore very shallow areas and having the ability to tune yet another trim variable for efficiency and performance sounded fun. Im an engineer and love having extra knobs to turn... It's worth noting that I also have electric trim tabs.
I was able to link up with another friend who hooked me up with a great deal on a Bob's Machine Shop hydraulic jack plate. It has 4" setback (lowest setback you can get while still having an integrated pump motor) and 6" of vertical travel. Its powder coated black, looks sick and I even installed a sweet, steering wheel mounted "turn signal style" switch to adjust height. I was super pumped to take it for a spin.
However, after a few trips and a couple hundred miles over the last few weeks, I am disappointed in the performance. AFTER installing jack plate, I seem to have lost about about 4mph on the top end and am back to getting like 3.5-4.5MPG (depending on fuel load). I also dont notice much change in performance based on jack plate position. I have 6" of vertical adjustment centered around cavitation plate being level with bottom of boat (cav plate 3" above or below bottom). Of course, I can bring motor up so high that it cavitates like crazy and my performance drops way off. But just below that point, all the way to full down position, I dont notice much difference in ride, speed/rpm or fuel economy. I can go crazy shallow now with motor trimmed down which is pretty cool!
Another complaint I have is that with this new motor, I no longer have as much bow-down trim capability as I would like. My honda had a permatrim AND a transom shim to give me even more bow down authority. Trimming that motor down plus full tab down would give you a scary amount of bow burying power! Great for running at 10-12mph in heavy ocean wind swell. With my new setup, I am almost always running with full tabs and motor trim down on flat water just to try to cut down on chop slap. Im dying for more bow down authority.
Pics for attention...
Before jack plate but check out the sweet transom brace that I laser engraved with my boat's logo! At this point I was almost done with rigging and ready for the first start!
Ok lets talk causes and solutions:
Issue 1: Poor performance after jackplate install:
Idea 1: The extra 4" of setback puts the weight of my 380lb motor even further back on boat. Not to mention additional ~40lbs of jack plate on transom. This combo is still lighter than many motors (for example, a Suzuki 115 can weight about 420lbs)
I have noticed that these boats seem very sensitive to weight in the transom. With my honda 90, the performance difference with 50 gallons of fuel back there vs. nearly empty tanks is astonishing. Not sure what exactly why, but id much rather have 300lbs worth of people up front than 300lbs of fuel in the back. I have noticed a little trim tab improves efficiency by maybe providing a little extra lift back there. Too much tab however can have the opposite effect.
One idea I had was to consider moving both my batteries way up front. I would probably need some pretty heavy cables to the motor for such a long run though. That would probably pull close to 80lbs off the transom.
Thoughts or experience here?
Idea 2: Maybe the additional setback puts the prop in more turbulent water?
I imagine the further back you get from the point where the water breaks free from the very aft edge of the hull, the more mixed up it becomes. Perhaps, now that my prop sits 4" further back, it's sitting in less "clean" flow? This might reduce efficiency? One common benefit of a jackplate with setback is that you can now run your motor a little higher up since the water has more time to rise after transitioning off the back of the hull before reaching the prop. I was really hoping that running motor high (just before cavitation sets in) that by reducing that amount of lower unit in the water, I would also reduce drag and get better efficiency. At the same time, I was hoping that running the motor extra deep would provide more stability, giving the boat a more planted feel in rough conditions. I dont really notice any of either of those benefits. Just overall worse performance.
Thoughts on this? I think my next step may be to try different props. Perhaps something about adding the jack plate also changed what prop design/size/pitch is ideal. Anything else I should try? Im tempted to remove the jack plate... id hate to because it's just so dang cool haha.
Issue 2: More bow-down trim authority
Like I mentioned earlier, I would REALLY like... no... NEED... more trim authority. These boats really shine when you can engage the V in the bow as chop starts to build. I was spoiled with the permatrim and 5 degree transom wedges. I could almost cause this thing to do a front flip.
Solutions:
1. Moving batteries forward may help some.
2. A prop with less bow lift? My current prop is a Michigan Wheel Ballistic. It has a lot of camber which apparently generates a lot of bow lift. The boat feels skatey and unstable at high speed (again, I realize this isn't a bass boat). I also need about 50% tab down and maybe about the same amount of bow down engine trim to keep from porpoising. This all seems to suggest to me that a prop with less bow lift would be helpful.
3. Bigger trim tabs? I could probably mount larger tabs. It would be great if they could operate off the same actuators. This would give me more bow down and left/right authority. Possibly even a little better efficiency due to more lift off the transom without needing such extreme tab angles?
4. Put a permatrim on my new Yamaha... I hate to do this since this motor is like 2 months old and has the prettiest bass boat sparkle blue paint job... drilling holes in a brand new engine would require several shots of whiskey to build up the courage. I would then be concerned with my ability to accurately place these holes... see the conundrum? However, peramtrims do provide some serious control surface area back there. I also wonder how a peramtrim would impact efficiency. It would add drag. Would this hurt my fuel economy and top end? Any other advantages beyond increased trim authority?
5. I could also add 5 degree wedges to the motor to allow for even more downward motor trim travel. I feel like im getting carried away now though. There would then be wedges and a jackplate between my motor and transom... Have I mentioned that I stay up at night wondering about the added stress on the transom with higher HP motor and the increased leverage from the jack plate? I do have a fairly recently rebuilt Coosa transom but can't speak to the quality of the job since it was commissioned by the previous owner.
Anyways... If you made it this far, thanks for sticking with me. I would love to hear everyone's thoughts and advice. I know there is a ton of wisdom on this site. Anyone else have experience with a jack plate on their 22 cruiser? Any prop recommendations?
Thanks everyone for the help!