Suggestions needed !!!

I'm a retired Boat dealer (lol) To me setting up these small boats is very different then the bigger boats I've dealt with.

I have a 4 stroke suzuki 20 on a Grizzly 1448. I have CM power tilt and trim, made a jack plate and no matter how I set it up I can get 22mph with just me in it. (185lbs) With one other person its very hard to plane. I've tried 2 ss props, SE sport 200 hydrfoil. it's a very heavy boat that I set up for floundering.
I have a 10" solas SS prop on it. I had tried a 9" SS thinking it would be better with another person, it wouldn't plane with just me, so I tried a 9" alm. 4 blade same thing wouldn't plane. Then I tried 11" SS prop got to 24mph with just me, but yery long time to get up.it only got 5700rpm. With the 10" ss it would 6200 rpm and gets on plane quick. the red line on the motor is 6300 rpm. I do have a lot of weight in it. A 24 volt minn kota 80 lb trolling motor with two 27 DC batteries up front and another battery in the rear for the main motor. I'm thinking smart tabs and doing away with the hydrofoil. I'm satisfied with just me in the boat, but I can not figure out how to do it with another person. I also thought a 4 blade Power tech prop may be good but I'm not sure.. I think my problem is I need a prop with a bigger diameter,
but that could be a Witch Hunt..

PS... I know some will say I need a bigger motor, but I don't want to do that.

i had a merc. 20hp on my grizzly. i removed the rear battery and ran jumper cable wire to the front bettery for power and starter. i also moved my fuel tank to under the console. i down graded to a 3 gallon that fit perfectly under the console. put my anchor under the front deck. i was running a 9.5" four blade. with gear, cooler, 2 people i could get 24mph. did not take long to get on plane if i stood up and leaned over the steering wheel. move as much weight forward as possible. i also noticed it got on plane and went faster without the stupid hydrofoil. i also removed my rock guard. make sure the cav plate is even with the bottom of the boat. mine was about 1" higher than the bottom. seemed to do the trick.

So when you say it won't plane you mean the bow is up in the air, it is not plowing, correct? It could be just weight distribution, trim tabs would help. I have a 1448 with a 20 hp 4s Yammi. My boat is pretty stripped but my tank is in the rear and my battery (I only use 1) and trolling motor are up front. My boat planes out quickly no matter how many in it. How do you have the motor trimmed? Is it trimmed all the way down? It may need to be if you load it up. When you have another person on board are you both sitting on the rear bench? Try moving the person to the front deck until on plane then he can move back to the middle bench. Usually weight distribution is very critical on a small boat.

I would try to rearrange the weight first, anything you add that forces the boat on plane also adds drag, also as mentioned above, make sure motor is at correct height. Start level with bottom then raise some if you can. I assume it is bolted on, move it up one bolt hole and if it blows out, move it back down. Tilt motor down one more hole, trim will affect it as well.

Thank you for the suggestion. I have a jack plate and C&M trim and tilt. I have had it from 1" below the bottom to 2" above the bottom. It really doesn't seem to make much difference. I had the two trolling motor batteries under the front compartment and that was to much forward weight so I moved them back just outside the compartment bulkhead that helps some. What I find strange is with a 10" SS prop it's OK with just me, but with another person it sucks. So I thought a 9"SS would be good with another person but it doesn't plane with just me in it. It just seems to cavitate and will not plane, it is definitely not a bad hub. I even tried 9" 4 blade alm. (same thing)

I'll do some more testing and let you know what I find.

Try this boat prop calculator for your specific hull or one listed that is identical as you can get. Add weight for all gear carried. Then run it twice, once just for your weight and then for the 2nd person.

https://www.tinboats.net/forum/viewtopic.php?f=4&t=37433 ... otherwise it seems like you've tried everything ...

Makes me wonder if the hull has a 'hook' in it - nothing works to correct that unfortunately less a bigger HP motor. Some hull designs intentionally use a hook (concave area on running surface from stern up to forward) to help carry the weight of the larger OBs, help it get it up on plane (but takes horsepower) and to keep it trimmed down towards the bow at high speeds.

You could place a long straight edge against your hull and see what you're dealing with. If indeed there is a hook, that 20hp might be on the edge of the performance envelope, sorry to say.

Smart Tabs will give you more speed after taking the hydro-tail off.
https://www.nauticusinc.com/smart_tabs_automatic_trim_tabs.htm

However, your issues seem to occur when you bring another person along. Smart tabs can be adjusted manually for increased pressure. That might give you better performance when switching loads/persons. I've never done it, and it might be a PIA to have to do it often by using the standard adjustment methods.

You know..... the pneumatic tabs are fastened to the hull, and to the tabs, with 3 or 4 different mounting points. I'd guess that one could arrange it so that the mounting points could be quickly changed, given the changes in person(s) aboard.

As I recall, the hull side mounting is just a pin or bolt. If that connection could be made using an easily pulled pin....then the change could be made quickly.

https://www.jergensinc.com/Kwik-lok-Pins



I'd give Nauticus a call. If you happen to get John, the owner, he knows and has seen all sorts of applications for his invention.

regards, richg99

p.s. Of course, you could always go to Lenco electric adjustable Tabs, but they are expensive and take up some room, too.