Won't plane out with more than 2 people onboard?

[Ki Ki]

Okay, so I've got a perfectly working 50 hp Johnson. It runs great, got a full tune-up and carb rebuild. It's a 50 hp 1970 engine on a 14.6 tri-hull. Anything more than 2 people and it will not plane out. I'm suspecting it's something to do with the trim level, which is manual.

Right now it's on the bottom most pin, the pin closest to the boat which means the motor is furthest down into the water. Any suggestions? I've never tried moving that pin up, but wouldn't that cause problems to try shifting it up? I really don't understand the manual pin dynamics.

 

[Silvertip]

Re: Won't plane out with more than 2 people onboard?

Well sir -- the reason there are more holes for the pin to go into is so you can TRY IT. If you have the motor trimmed all the way IN that pushes the bow DOWN so the boat plows. Move the pin one hole at a time and try it. You need to understand that trim is provided to adjust for the load you have. With manual trim you must set it for what you have most of the time. If you set it up for one or two people it probably won't be best for three. That's why engines in that range now have power trim.

 

[Ki Ki]

Re: Won't plane out with more than 2 people onboard?

Well sir -- the reason there are more holes for the pin to go into is so you can TRY IT. If you have the motor trimmed all the way IN that pushes the bow DOWN so the boat plows. Move the pin one hole at a time and try it. You need to understand that trim is provided to adjust for the load you have. With manual trim you must set it for what you have most of the time. If you set it up for one or two people it probably won't be best for three. That's why engines in that range now have power trim.

Is that generally how it works with the trim- closer to the boat the lower the bow goes? I'd think that HELPS it plane...

Also, where do most people keep their trim on a manual outboard. In the middle pin?

 

[BuzzStPoint]

Re: Won't plane out with more than 2 people onboard?

If you use the hole closest to the transom, it will want to raise the bow of the boat.

If you start to put the pin outward, the bow will go down.
I have a 14 foot glastron.

If I put the pin in closest to the boat, I'll plane out, but the bow is a bit higher and slow. Through trials, I now have the pin in the 3rd hole outward, (I have 4 holes), The boat planes, not as fast as the 1st hole, but I get eh best speed.

Another thing to look at, How much weight do you have in the back of the boat. Try to put more weigh up front.

 

[Silvertip]

Re: Won't plane out with more than 2 people onboard?

Obviously trimming in does not help you get YOUR boat on plane with three people on board. Envision a side view of the boat out of the water. Trimmed fully in the prop will have a slight upward thrust angle -- in other words it is trying to raise the stern. That my friends drives (holds) the bow down. That amounts to too much in trim for a three person load on your particular boat. The reason it can't get on plane is because the engine can't "lift" the bow because it is pushing it down. That does not apply to all boats, all motors and all loads because transom angle and engine design have a bearing on what the thrust angle is at full in trim.

Moving the pin so the engine sits more straight up and down (prop pushes parallel with the waterline) will undoubtedly help. But you need to experiment.

There is no one size fits all with trim settings on manual or power trim systems. The engine, the boat, and the load all dictate what the trim setting should be. Your issue is to determine what works best most of the time. In other words figure out what the load will be most of the time and then experiement with trim to get the best performance "for that load".

 

[Ki Ki]

Re: Won't plane out with more than 2 people onboard?

Obviously trimming in does not help you get YOUR boat on plane with three people on board. Envision a side view of the boat out of the water. Trimmed fully in the prop will have a slight upward thrust angle -- in other words it is trying to raise the stern. That my friends drives (holds) the bow down. That amounts to too much in trim for a three person load on your particular boat. The reason it can't get on plane is because the engine can't "lift" the bow because it is pushing it down. That does not apply to all boats, all motors and all loads because transom angle and engine design have a bearing on what the thrust angle is at full in trim.

Moving the pin so the engine sits more straight up and down (prop pushes parallel with the waterline) will undoubtedly help. But you need to experiment.

There is no one size fits all with trim settings on manual or power trim systems. The engine, the boat, and the load all dictate what the trim setting should be. Your issue is to determine what works best most of the time. In other words figure out what the load will be most of the time and then experiement with trim to get the best performance "for that load".

That's a good point about having the prop push along the waterline. I'm going to pick which level would provide the most equal lift. That should help. Thanks guys

 

[cougar1985]

Re: Won't plane out with more than 2 people onboard?

good starting point is about 3rd hole from bottom.BUZZ ,you must have about the only boat in the world the the bow would rise from the hole closest to the transom!the bottom of the motor closest to the transom will push the stern up thus the bow down and as you trim out you raise the front.

 

[Ki Ki]

Re: Won't plane out with more than 2 people onboard?

good starting point is about 3rd hole from bottom.BUZZ ,you must have about the only boat in the world the the bow would rise from the hole closest to the transom!the bottom of the motor closest to the transom will push the stern up thus the bow down and as you trim out you raise the front.

Third hole from bottom? I'll try that before we go out tomorrow, thank you. I think right now it's on the 1st or 2nd closest to the transom. I want a combination of planing out and smooth ride. Sounds like the third hole- medium ground- makes sense.

Okay. I checked, it's currently on the 2nd hole CLOSEST to the transom. Should I go to the 3rd hole closest to the transom. In other words raise it one time. I'm afraid I could mess something up with the motor, possible?

 

[cougar1985]

Re: Won't plane out with more than 2 people onboard?

yes just keep going up 1 at a time till you get the performance you want ,you will know when its right .the worst that can happen is the motor if trimmed out too far will caviatate so if that happens go back one ,and so on.

 

[Ki Ki]

Re: Won't plane out with more than 2 people onboard?

So I trimmed it to #3 away from the transom tonight. It's obviously now though not level to the boat's bottom. The prop is slightly aimed upward with the engine hood slightly facing down.

What type of action, in theory, would this provide for the boat?

 

[eavega]

Re: Won't plane out with more than 2 people onboard?

Think about it. If the prop is pointed up when the boat is level, then its going to push against the transom of the boat at a downward angle, which will bring the bow up (like pushing down on a see-saw raises the opposite end). The result should be less hull in the water, and therefore faster planing. That will totally depend on the configuration of your boat, though.

-E

 

[Joshua Nichols]

Re: Won't plane out with more than 2 people onboard?

My ol Ebbtide had the holes for adjustment... It was a old boat 16ft with a 65 Johnson... When I got it it was in the second hole from the transom.. Put it in the third hole just for fun cause I like to mess with stuff and it would run faster and planed out better... So give it a shot

 

[BigB9000]

Re: Won't plane out with more than 2 people onboard?

I would recommend buying and fully reading a owners manual for your outboard.

 

[trendsetter240]

Re: Won't plane out with more than 2 people onboard?

So I trimmed it to #3 away from the transom tonight. It's obviously now though not level to the boat's bottom. The prop is slightly aimed upward with the engine hood slightly facing down.

What type of action, in theory, would this provide for the boat?

This may help to improve your top speed but will not help you plane out faster. Having the motor set on pin#2 which sounds like neutral trim (in line with the bottom of the boat) is your best bet. Engines with power trim are trimmed in to improving time to plane, not out.

Next time you head out on your boat alone or with 1 passenger check what RPM you get at wide open throttle. Your prop may have too much pitch for that setup and you may benefit from a new prop with lower pitch. Your engine should be able to reach the manufacturer's recomended RPM at WOT.

Cheers.

 

[kenmyfam]

Re: Won't plane out with more than 2 people onboard?

There's a lot more than trim to get the best set up. Motor height, trim, proper loading of people and equipment, location of fuel tanks are but a few things that need to be considered. When you get the best you can from that lot you can then move on to the prop pitch.

 

[Silvertip]

Re: Won't plane out with more than 2 people onboard?

It took 36 posts to get a trailer coupler changed. We are now on 14 posts to get this trim pin set. I suggest again that you won't know what's correct until you "try it". It simply works this way: Too much trim out the bow goes high. Too much trim in and it plows. Happiness is somewhere in between. On a boat that size the number of people you have in it and where stuff is positioned makes a difference how trim is set. "Experiement".