Bass boat trim authority sucks in mid range

[Eddie1920]

I have 1985ish Bass boat that proporise if I trim up much in the mid range 2500-3500 rpm range, 28-38mph. 4500 rpm 42mph or up i can trim it to max and its great, but I fish casually and the wife doesn't like the speed so im always cruising around 32-45mph, current prop is a 21p 3 blade yamaha m series ss, is there other props that will allow me to trim the boat up in my mid range cruise, I dont need top speed but current top speed by my self is 53.4 mph at about 5300 rpm

 

[Eddie1920]

 

[jimmbo]

I suspect you are trimming up too much at the lower speed. The standard mode of operation, is trim out until it start to porporise, then trim it in until it stops
You could try a Merc Enertia, it is a prop that will lift the bow, in fact the entire boat will be lifted vertically out of the water.

 

[redneck joe]

if it is a mid range prob yeah just a trim issue

 

[Eddie1920]

I suspect you are trimming up too much at the lower speed. The standard mode of operation, is trim out until it start to porporise, then trim it in until it stops
You could try a Merc Enertia, it is a prop that will lift the bow, in fact the entire boat will be lifted vertically out of the water.

No i dont think so. I almost can't trim it at all in mid range, the steering is still heavy and its not even close to being up on pad, iv played with engine height and bringing up the height made it worse, My prop to pad is about 5.75" and I'm on manual jack plate with 5.25" set back

 

[redneck joe]

heavy steering and porpoising are two different issues

 

[Chris1956]

Most boats can be trimmed more at higher speed. It is therefore normal for you to use max trim as you approach max speed.

At all speeds, you want to trim up until the steering is light, or until she starts to porpoise, whatever you prefer. Some boats allow both, but most will pull left (right hand prop), as trim becomes more extreme.

You can also set your trim tab (anode) to make the steering neutral at higher trim angles. Of course, that will make the boat pull harder right (right hand prop), when trimmed down.

 

[redneck joe]

Most boats can be trimmed more at higher speed. It is therefore normal for you to use max trim as you approach max speed.

At all speeds, you want to trim up until the steering is light, or until she starts to porpoise, whatever you prefer. Some boats allow both, but most will pull left (right hand prop), as trim becomes more extreme.

You can also set your trim tab (anode) to make the steering neutral at higher trim angles. Of course, that will make the boat pull harder right (right hand prop), when trimmed down.

yep, thats what i meant to say...

 

[Pmt133]

It sounds like you may have a few things going on here as others have said... but at the lower speeds I wouldn't expect the boat to be up on the pad so to speak. A true neutral lifting prop like the enertia would help that greatly but that's only one piece....

 

[Chris1956]

Gee, does that boat have a pad? Some don't. Your RPM is a bit low, based on experience, although the prop pitch sounds right.

Run on plane at cruise or faster and see what the antiventilation plate is doing. It should be on top of the water. If not, maybe raise the motor 3/4".

 

[Ifishmuskie2]

Maybe a simple way ( I know it works on some boats). Run the speed you want and adjust the trim to stop the porpoise. If you don’t change the rpm much then you have the sweat spot.