Pontoon Boat & Deck Boat Forum

I bought a Crest DL2 my first pontoon boat, it has a 75 hp Honda 4stroke. When I bought the boat it had a 14x11 3 blade prop @ 5800 rpms it would run 13mph. I bought a 4 blade 13.8x10 6000 rpms 10 mph had a prop shop put some cup in the prop then 13 mph 5500 rpms, I then bought a 14x13 4 blade@5400 rpms 14 mph. I want this boat to run about 18 to 20 mph, is this possible or am I just wishing for something that wont happen. Load is 4 adults 3/4 fuel w/clean toons i cant even pull a kid on a tube like this any advice

as with everything, the answer is, it probably depends. I think it should. how long is it? how big are the 'toons? How much gear do you pack on?

I have an older 25' with a 75hp 4 stroke efi merc that's seen some hours and with 4 adults (in pretty good shape) and our children we regularly can hit 18-19 with WOT but usually cruise about 16 according to both phone gps and Garmin plotter GPS. My tach is broken so I can't give you RPM's. Even with some of our larger friends we still hit 17-18 and cruise at 15-16

Just for comparison purposes, I have a 22' Sweetwater with a Yamaha High Thrust 50 hp, 14x11 prop @ 5800 rpm. I get exactly 20 (gps) with my wife and I on the boat in calm water.
KPC

Kpc it is 21ft with 23 inch toons I can have 4 adults 2 kids or just 2 adults life jackets and a anchor it really doesn't change more than a half mph. I dont quite get whats happening trimming it makes very little difference, moving people to the back no difference. The speed is measured by phone, gps speedo and a Garmin Striker +4 all read the same.

I would think 18-20 should be more than attainable. How to get it? others with more experience will have to chime in

Four blade props generally have less top end speed than three blade models. that extra blade helps with the hole shot, but the tradeoff is top end.

Assuming your toons are clean and there's not any obvious source of drag, you still may not be able to get to 20 mph. Pontoons are displacement hulls. They really aren't designed to plane, so they push through the water instead of getting on top of it. Larger toons, tri toons, lifting strakes, etc. can all increase buoyancy and help the toons plane somewhat. But your combination of small toons may just not have the ability to get up and out of the water enough to really increase speed. You might be able to get a large enough motor to offset the drag of the displacment hull, but that would cause other issues, like burying the front end if you hit small wakes/waves.

Just a thought......you may want to bring it to a truck scale and weigh it. I'm wondering of you may have water in your toons.

Jamie 10017 wrote: ↑

Wed Jun 30, 2021 1:44 pm

Kpc it is 21ft with 23 inch toons I can have 4 adults 2 kids or just 2 adults life jackets and a anchor it really doesn't change more than a half mph. I dont quite get whats happening trimming it makes very little difference, moving people to the back no difference. The speed is measured by phone, gps speedo and a Garmin Striker +4 all read the same.

Wish I could help you more but I can't. Every boat is different. Distribution of weight makes a difference. Toon size makes a difference. Motor height makes a difference. Heck, I know I can lose 2-3 mph just by having scummy tunes. I always keep a very fine Scotch Brite pad on the boat and I wipe down the bottom of the logs while we're at the sandbar.

KPC

Thanks to everyone who replied I guess I'll have to settle for what I have for now. Possibly look for a newer faster boat. Have a great and safe 4th of July