Help slow down my 259!

[paulsboats]

Once again, I'm going to bring this up.....and most likley get made fun of (or at least 'thought' stupidly of)....BUT I have had my Convincor for 7 years, and when I bought it, it porpoised really bad. I didn't have the 'seat time' because it was a new boat. I installed a Stingray Hydrofoil and it works. That was when the boat was stock and ran 55mph, now it runs low 70's and I still have it on. I have expiermented with AT LEAST 10 different props, lengthened my tabs another 8 inches(no help), took the stingray off and on.......final setup is a 26 Bravo One with the stingray installed, and factory length tabs. I notice no top speed difference with it on or off, but the cruiseability is much more enjoyable and it planes faster. It is still a "drivers boat", you still have to adjust trim and tabs, just a little less and much less porpoising or bouncing. I know its not something you see on performace boats, and yea its a little embarassing to say i have it, but it works for me. I do also agree that seat time is a big factor, because these boats ARE drivers boats, unlike a baja or other beginner boats.

They do work very good!im going to add one to my boat,have used them on other boats and it made a big difference in drivability

 

[jazzy]

I've been going through a similar dilemma. I have a 6 month old at home now and I don't want to sour him on the boating experience this summer. I've been looking at beater boats that I could suck it up and run for a year or two then dump. Or even a cruiser to leave in the water for family trips and keep my boat for good days. That new bayliner bow rider model is very tempting, I would feel a little weird pulling up to the beach in a 17 ft bayliner but a day on the water with the family is a hell of a lot better than a day in the shop polishing my hustler.

 

[RNGRDVE]

I've been going through a similar dilemma. I have a 6 month old at home now and I don't want to sour him on the boating experience this summer. I've been looking at beater boats that I could suck it up and run for a year or two then dump. Or even a cruiser to leave in the water for family trips and keep my boat for good days. That new bayliner bow rider model is very tempting, I would feel a little weird pulling up to the beach in a 17 ft bayliner but a day on the water with the family is a hell of a lot better than a day in the shop polishing my hustler.

I'd go cruiser or toon. Either would be nice to have for years to come.

 

[Jimway]

Oh-no, I hope I'm not seeing a pattern here. I was recently way layed by a certain Mrs. Jim, who was all made up, and asked if I would like to spend the afternoon with her doing something that 'I would really like'. I must confess that my mind may have wandered some, enough so that I made sure that I was showered up and even wearing clean clothes. She took me out to lunch. It was very good. She sat next to me. As usual, she smelled really good. She commented on how well behaved I have been, under her watchful eye. She laughed at all of my jokes. I began to feel excited for the afternoon's possibilities. The Sun peaked out from the clouds, birds were singing and flitting about, even the traffic on the road seemed light and agreeable. In hardly no time at all, we pulled into a driveway. Mrs. Jim held my hand as She walked me around the side of the house. As we rounded the corner of the house, there it was. Mrs. Jim happily showed me about. "Gulp" I said. " Look at the hull, it's like new" She said. She jumped up the ladder left standing next to the rear, " S' got a small block in it" She winked, as She raised the engine hatch. "Honey look at this" She says, as She points out the stove and refridgerator. "Has a bathroom with a shower too" She added. " Nice big bed down there" She says and raises one eyebrow all sultry like. I desperately looked around for something wrong with the big vessel but , much to my chagrin, found nothing. I do have to admit that it is a nice vessel but guess what it says right there on the side....

 

[jazzy]

I'd go cruiser or toon. Either would be nice to have for years to come.

Can't do a toon, lake Erie would break one in half on most days, I've been looking at old sport fish models they're pretty reasonable. But a little runabout would be more practical for us right now. Buying a second boat kind of screws with my plans of buying a bigger go fast though so I'm in no hurry

 

[slingblade]

Ok I know that's something most of us don't usually say but to justify keeping my boat I need to make it more family friendly. I want to make it ride and handle better between 30 and 50 mph. Top speed isn't a factor. Right now in that range it has the checkmate bounces really bad. From what I have reason here I think it's worse than some. The prop is a 24 bravo 4blade. As soon as the boat noses over the prop lets go. When driving slow , the only thing I can do is drag the tabs and adjust the throttle constantly as the prop hooks up and then unloads back and forth. With the tabs down the boat turns like it's going to flip over. The only reason I want to do this is because my son is only going to be a few months old when we start boatin and to keep the peace and for safety, running 55+ like I usually do is something I need to change. What do you all think? Should I try like a 22 pitch high 5? Or how about a bigger 4 blade. With more cup and diameter? I'm going to keep a high speed prop too but indeed to make things safer for my boy. Thanks!

sounds like a pontoon is near..
Just kidding.
I just put a wing,foil or what ever you call them things on my Uncle johns boat this past weekend.
It fix about 4 problems that it had. Comes out of the water 10 times quicker and with far less throttle. Also it will run low speed and stay on plane. I mean allot less speed . The trim works allot quicker also . It needs far less trim to go full speed . After adding the foil the only down side I could find was the boat would lean to the left instead of flat at med speed. But with trim tabs that should be no problem . I would try one. It would be like riding on a Pad .
With that being said ,I know crap about boats compered to most on here including you. but it made a huge difference in his set up.
I have no idea about how strong the outdrive is there or how it would take wave pounding on a I/O but I am sure some one knows. .

 

[fox88gt]

I see you are running the propeller that came on the boat when you purchased it. I would recommend finding a reputable propeller shop and see if you can try different props. A hydrofoil on a Mercruiser (especially on a Checkmate) is a huge for me....chances are you can find a prop with more bow lift, or maybe more stern lift, to reduce the porpoising at medium speed. Hydrofoils are band-aids for a boat that isn't propped correctly. I mean no offence to those who have one.

Also, are you adjusting drive angle to help counter the porpoise, or just using tabs? Tabs won't do much to correct a porpoising boat. Drive angle can fix it in a second.

 

[fox88gt]

When I try and run slow I'm trimmed all the way down. I don't even touch it until about 50 mph.

I also saw this and would recommend to adjust trim - even when you are just cruising. Your wallet will thank you! You're wasting gas trimmed all the way down and probably causing the porpoising as well.

 

[cooperider]

Oh-no, I hope I'm not seeing a pattern here. I was recently way layed by a certain Mrs. Jim, who was all made up, and asked if I would like to spend the afternoon with her doing something that 'I would really like'. I must confess that my mind may have wandered some, enough so that I made sure that I was showered up and even wearing clean clothes. She took me out to lunch. It was very good. She sat next to me. As usual, she smelled really good. She commented on how well behaved I have been, under her watchful eye. She laughed at all of my jokes. I began to feel excited for the afternoon's possibilities. The Sun peaked out from the clouds, birds were singing and flitting about, even the traffic on the road seemed light and agreeable. In hardly no time at all, we pulled into a driveway. Mrs. Jim held my hand as She walked me around the side of the house. As we rounded the corner of the house, there it was. Mrs. Jim happily showed me about. "Gulp" I said. " Look at the hull, it's like new" She said. She jumped up the ladder left standing next to the rear, " S' got a small block in it" She winked, as She raised the engine hatch. "Honey look at this" She says, as She points out the stove and refridgerator. "Has a bathroom with a shower too" She added. " Nice big bed down there" She says and raises one eyebrow all sultry like. I desperately looked around for something wrong with the big vessel but , much to my chagrin, found nothing. I do have to admit that it is a nice vessel but guess what it says right there on the side....

Bayliner

 

[Kurtster]

I would feel a little weird pulling up to the beach in a 17 ft bayliner but a day on the water is a hell of a lot better than a day in the shop polishing my hustler.

 

[ajexpress]

If you think your 24P bravo is not stock, I have one on the way from a forum member. We could meet on the water and let you try it out and see what you think. If you think it's stock, I'd play with the prop as some have mentioned.

I see this guys handle a lot on offshoreonly

http://bblades.com/

 

[fast94persuader]

I also saw this and would recommend to adjust trim - even when you are just cruising. Your wallet will thank you! You're wasting gas trimmed all the way down and probably causing the porpoising as well.

If I do any more than barely click it, it starts the porpoise or "death hop" as I call it.

 

[fast94persuader]

If you think your 24P bravo is not stock, I have one on the way from a forum member. We could meet on the water and let you try it out and see what you think. If you think it's stock, I'd play with the prop as some have mentioned.

I see this guys handle a lot on offshoreonly

http://bblades.com/

I appreciate that but my boat has an x drive and I'm not sure how hard it is to change out the hub. Maybe at least I can look at it sometime.

 

[v324908]

I've had both a Bravo and a Hydromotive prop on my 251. I like the Hydro much better for slower cruising. I believe it creates more stern lift which equals less porpoising.

 

[miller]

I can see where the whaletails would help planing time, but even trimmed the whole way down at cruising speed my antivent plate is around 2 inches above the water. Isn't that where they are mounted?