Trouble getting on plane

[Milton]

I have a 2800 and I'm having a hard time getting on plane. Any ideas on what props I should have. I have 2 4.3 v6 motors

[mmwjr]

Originally Posted by Milton

I have a 2800 and I'm having a hard time getting on plane. Any ideas on what props I should have. I have 2 4.3 v6 motors

What is the WOT of your boat and what props do you currently have? Is the bottom clean of marine growth? Can you better define hard to plane? How many souls on board?

[marcucho]

Originally Posted by Milton

I have a 2800 and I'm having a hard time getting on plane. Any ideas on what props I should have. I have 2 4.3 v6 motors

Welcome to my world :-) , I have a 2000 2800 with B2 twin 4.3 and I had hard time to get on plane after swim platform was added. It was impossible to get transom out of the hole due to the dragging from the swim platform. Specially when the boat is l loaded with cooler, 3/4 gas tank, water and 4 or 5 people in the cockpit . I had the trimtab down and the outdrive down, I could go 4200 RPM and still dragging. Waste of fuel. Propeller SS 3 blades I believe were 19 or 18 . They were replaced with 4 blade SS 18.5 P16 and finally the boat gets on plane just reaching 3500 RPM with trimtabs down and outdrive down. I can lower down the rpm to 3000 ~3200 and still on plane, BUT it will come out of plane now and then so I have to get back to 3500. I think that WOT was on 4200 with the new 4BSS Propellers. I lost around 300 or 400 rpms and the speed at 3500 RPM was around 28 ~ 29 MPH , I remember going 32 MPH when I did not have the swim platform + all the xtra weight ( house batteries bank, etc ) with the 3 blades SS ones.
I think that I could get back to 32 MPH with some outdrive / trimtab and carburetor adjustment.
At least I can get the boat back on plane with the 4 blades SS Props.

[Mr Hemi]

Originally Posted by yahoo82

Maybe we can get some comments from others on their normal cruising speed/RPM. 3800-4000 rpm is typical for me as the boat just feels happier there.

One thing you could try is to see if you are actually at (or near) the same throttle position when running at the higher end as the lower end. Since fuel usage is a function of boat speed, RPM and load, you may find your burning the same amount of fuel because the boat isn’t dragging through the water as much, and you end up with less load in the engine but at higher speed. I put together the attached chart for my boat when I was changing props. The most efficient place was ~3750 RPM but going +/- 250 TPM from there only impacted fuel about 0.05 Gal/Mile … like 7%. It was worth it for a more comfortable ride. No-one buys a boat to save money lol .

(Note those are my old speeds from before I changed from AL to stainless props)

Attachment 7258


Sent from my iPhone using Tapatalk

I agree with Yahoo.

I can be on plane at a lower RPM, but it runs much smoother once you find that sweet spot on plane.(usually higher RPM).


I would rather give up maximum speed so I could get on plane easier, and use less fuel in the process.
Cruise will be lower, but so will fuel burn.

My suggestions.
1. Dont fill water tank.
2. Dont fill fuel tank if you dont need all that fuel.
3. Seems a lot of boats come with tabs not big enough for boat.
4. If you cant reach minimum 4400 RPM you are overpropped, or you have performance issues.4400RPM is the low side of your maximum 4800 max RPM.

My boat is complexly different beast once I drop weight, even with anti-fouling paint and oversized swim platform.
My 2 cents.

[Mr Hemi]

Quick Note: I did go to a 4 pitch on my Bravo 3.
Made a Big difference for getting my heavy ass boat on plane.
I dropped from a 22P to a 20P and my maximum RPM is right around 4700RPM.

You want your maximum RPM to be based on how you load boat, not on a empty boat trying for max RPM.
If you usually have 4 people on board, then thats what your Max RPM should be based on.
Im sure someone will correct me if I am wrong.
Good Luck.