How to set trim on a pontoon boat.

[N80]

I know next to nothing about boats of any sort. My parents have had a 20" pontoon boat for several years and I know how to getting running and have a good time with it. But, the old Mercury on it was starting to have trouble and so they just bought a Yamaha 60 hp 4 stroke. Brand new. Looks funny on the old pontoon boat.

We were driving around on it late last afternoon....when the temp dipped below 98 going through the break in period. I read the manual and it places a lot of emphasis on getting it trimmed out properly.

Well how do you know when the trim is right on a pontoon boat? A 60 hp motor really doesn't noticeably lift the bow up or shove it down regardless of the the trim setting. And I'm assuming that a pontoon boat doesn't really trim up or down anyway. But the manual mentions that the engine is much more efficient if the trim is set right and I'm also assuming that getting it trimmed right, even on a pontoon boat, is important.

So how do you know when its trimmed right since bow height really doesn't change? Do you just have to ride it around and listen to when the motor sounds like its running best or do you just try to set it roughly 'level' with the water?

 

[Willl]

Can you even get a pontoon boat up on a plane ?

I would say if you can't, trimming it the way you got it is close enough.

If the nose isn't porpoising or plowing, should be good.

 

[N80]

Can you even get a pontoon boat up on a plane ?

No, I think the pontoons just sit flush in the water no matter what. Now, you may be able to mount a motor big enough to raise the bow up.....I'd like to see that.

 

[bigtiller]

When my family had a 24 footer with a 60 hp motor we would set the throttle at the noise level that we could stand and then raise or lower the trim to the highest rpm the motor would produce and still pump water through the engine.

 

[Skyco]

If you have a speedo and tach set the trim so the maximum speed is attained at the minimum rpm. Try to find the spot where you like to cruise (speedwise) and play with trim to get the maximum speed with minimum rpm. Don't know if it happens with a pontoon boat but with some regular boats, trimmed for maximum speed with minimum rpm will cause the prop to breakout in a hard turn unless one trims in a little for the turn.
I'm assuming you don't have power trim?

 

[Tig]

A pontoon boat is a displacement hull so trim will end up quite neutral, square to the boat it's self. It's not nearly as critical as on a hull that planes. As far as performance goes load distribution is more important.
The neighbour has a pontoon boat with a 90 and power trim. It does seem to plane but not very nicely.

 

[N80]

Thanks guys. It does have a tach. And it does have power trim. So it sounds like I need to experiment a little with the tach and engine sound.

Skyco, tell me what you mean by the prop breaking out. With their old motor, in a hard fast turn (of course fast is relative to pontoon boats) the engine would rev high but you'd lose power. I have not seen this with the new motor but its still in the break in period so we've been taking it easy.

I never could figure out what was actually happening. Do you know what causes prop 'breakout'?

 

[kenmac]

If if will help . They use to make a trim gauge. You can add

 

[kenmac]

Prop break out ?? Are you talking about when the prop blows all the water away from it. If so, the trim is usually too high & the foot of the motor is close to the top of the water which, causes the prop to blow away what little water that is around it away from it

 

[MrJimi]

First of all, you need to know the max RPM for the engine is, then get a prop/pitch that will give you just under that.. Noise has nothing to do with it
Let's say engine RPM is 5,800. You need a prop/pitch that will let it rev to just under that, let's say 5'600 RPM and SS props will do ever soo much better than aluminum prop
all you need is a good sharp outboard mechanic.
Happy boating