Semi-V bow lift yes or no?

[omcstratos]

I have watched numerous videos of fast jonboats. This one is one of my favorites, http://www.youtube.com/watch?v=SaLb0-y0Fvg.

The question I have though is do these boats run a high bow lifting prop or a transom lifting prop. I have run one of Ron Hill's thru hub cleavers and the boat porpoises so bad you can't drive through it even trimmed down. I always thought high rake and bowlift were for v-pad bottoms but does that work well on jonboats too?

[omcstratos]

Anyone want to throw their 2 cents in? Don't know if a cleaver style or chopper style prop would work best on a flat bottom boat.

[HankFrazier]

I have watched numerous videos of fast jonboats. This one is one of my favorites, http://www.youtube.com/watch?v=SaLb0-y0Fvg.

The question I have though is do these boats run a high bow lifting prop or a transom lifting prop. I have run one of Ron Hill's thru hub cleavers and the boat porpoises so bad you can't drive through it even trimmed down. I always thought high rake and bowlift were for v-pad bottoms but does that work well on jonboats too?
We SRG run flat bottom and semi v jon boats we run nothing but cleavers they work the best for us. they have plenty of bow lift. some jon boats are very hard to get to set and run with out porposeing their are some things u could try.

[HGipson]

Hank, What all can be done to stop the porpoising at high speed on a Semi V jon boat ? Got my motor on a jack plate cavitation set level with bottom. 60 Etec on 1546 Alumacraft. Been trying to find some answers to get it back down so I can get more trim an speed out of it

[HankFrazier]

Hank, What all can be done to stop the porpoising at high speed on a Semi V jon boat ? Got my motor on a jack plate cavitation set level with bottom. 60 Etec on 1546 Alumacraft. Been trying to find some answers to get it back down so I can get more trim an speed out of it
send me some pics of your setup and i'll try to help.

[BRzuki]

I wouldn't waste your time. I've told him countless times over the last 4 or so months how to fix his boat to sit back on its tail and run out and he has yet to try anything I have told him.

[HGipson]

Yeah he told me to take a hammer and block of wood and beat a hook into my hull. If that's what I gotta do Id rather just have a crappy running boat

[BRzuki]

Yep...I haven't slowed a boat down yet doing that either.

Also said to try a low rake prop instead of that 20+ degree raker, weld trim tabs on the back and adjust them accordingly, put a higher pitch prop on and see if the increased speed will settle the nose, or at the very least try to trim through the porpoise....

[Fastjeff57]

How about adjustable trim tabs? I use a Lenco electric cylinder to adjust the porpoising out of it (for comfortable cruising). THe tabs are pulled up for speed runs at a touch of a switch.

Jeff

[Smokin' Joe]

Yeah he told me to take a hammer and block of wood and beat a hook into my hull. If that's what I gotta do Id rather just have a crappy running boat

Get a straightedge. Does the running surface have a rocker? Take it out.
Square the trailing edges at the transom. I now have new props available
for the OMC 2 cyl and 3 cyl loopers, castings OMC made for EP/SE
earlier. These are the trick.

[HGipson]

That's a sweet lookin prop! I'm going to try and get this thing going. The porpoising just gets horrible when you try to trim through it. Ron told me to jack the motor up about 2" above bottom and run it and maybe need to get some more set back. Said that Raker wasn't that bad of a prop so I'm gonna try it out this week and see. Jordan, you're the only one Ive talked to that said to beat the bottom ribs into a hook and everyone else is saying don't. Keep that Edge on Craigslist a little longer if that 556 Edge duck boat with that mildly mod 60 really runs mid 60's then I imagine one of these guys will run with it

[MWhite]

That's a sweet lookin prop! I'm going to try and get this thing going. The porpoising just gets horrible when you try to trim through it. Ron told me to jack the motor up about 2" above bottom and run it and maybe need to get some more set back. Said that Raker wasn't that bad of a prop so I'm gonna try it out this week and see. Jordan, you're the only one Ive talked to that said to beat the bottom ribs into a hook and everyone else is saying don't. Keep that Edge on Craigslist a little longer if that 556 Edge duck boat with that mildly mod 60 really runs mid 60's then I imagine one of these guys will run with it

Hgipson,, is your boat heavey, if it is,, u might not have enough motor to pull it out of the bouncing so bad, i had one that was heavey and no matter what i did,,, it done this,, i didnt have enough motor to get it out of it,, just saying. I got me another boat. lol

[BRzuki]

That's a sweet lookin prop! I'm going to try and get this thing going. The porpoising just gets horrible when you try to trim through it. Ron told me to jack the motor up about 2" above bottom and run it and maybe need to get some more set back. Said that Raker wasn't that bad of a prop so I'm gonna try it out this week and see. Jordan, you're the only one Ive talked to that said to beat the bottom ribs into a hook and everyone else is saying don't. Keep that Edge on Craigslist a little longer if that 556 Edge duck boat with that mildly mod 60 really runs mid 60's then I imagine one of these guys will run with it

Boat isn't for sale anymore...I gotta come whoop all y'all cache and white river boys. The hook is the same as trim tabs except its a more fluid approach compared to trim tabs which are more abrupt in my opinion. Plus you are only doing the two outside ribs...nothing even close to the motor. It will end your porpoising and get your speed up. Will it essentially put a speed limit on your boat...yes it will. That's why these guys warm against it. However with your motor and set up, you will most likely not be reaching it as it will be in the mid 50's.

You will gain 4-5 mph and have a smooth ride to boot.

[HGipson]

My boat weighs around 425 plus motor 240. I can email pics to anyone that needs em. The boat used to be rated for a 25 hp so I figured why not double it! Lol. New boat no damages at all. Ground the weld down on bottom of transom while I was adding my touch to it after u bought it. Thanks for any help.

[MWhite]

My boat weighs around 425 plus motor 240. I can email pics to anyone that needs em. The boat used to be rated for a 25 hp so I figured why not double it! Lol. New boat no damages at all. Ground the weld down on bottom of transom while I was adding my touch to it after u bought it. Thanks for any help.

What kind of motor and boat u got?

[HGipson]

I've got a 1546 Alumacraft Semi V with 15" transom. Got a 60 Etec on a 5" set back jack plate with a BRP RAKER 18" pitch. Boat weighs about 425 lb plus motor and fuel. Rated for a 25 so a 60 should scream I imagine anyway! I can email or text pics to anyone that can help. Cav plate is set right at or 1/4 below transom appreciate any help

[MWhite]

I've got a 1546 Alumacraft Semi V with 15" transom. Got a 60 Etec on a 5" set back jack plate with a BRP RAKER 18" pitch. Boat weighs about 425 lb plus motor and fuel. Rated for a 25 so a 60 should scream I imagine anyway! I can email or text pics to anyone that can help. Cav plate is set right at or 1/4 below transom appreciate any help

cav plate is 1/4 inch below bottom of boat?

[HGipson]

Yeah right now it is. A guy told me to lower it to stop porpoising didn't make much since but it didn't help either. Haven't drove it since then

[MWhite]

Yeah right now it is. A guy told me to lower it to stop porpoising didn't make much since but it didn't help either. Haven't drove it since then
U need to rise the motor atlease 2 to 3inches,and get that cav plate above water 2 to 3inches, it shouldnt be in the water, try this and see if this helps any. good luck.

[MWhite]

Yeah right now it is. A guy told me to lower it to stop porpoising didn't make much since but it didn't help either. Haven't drove it since then

u got a e-tec60,, i dont know what the gear ratio is on these motors but i bet they are geared lower for power not speed and that could be hurting u too. just saying.

[BRzuki]

Gear ratio on the 60 etec is 2.67:1

[HGipson]

Believe its geared 2:67. Should be able to just run a higher pitch to make up I would think anyway?

[MWhite]

Believe its geared 2:67. Should be able to just run a higher pitch to make up I would think anyway?

gear 2.67 thats for power and carrying a load,,, not speed, u turning alot of rpms and not going no where,,,, u can try a higher pitch prop,,, but this is always going to hold u back,

[BRzuki]

http://www.ptprop.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=33&category_id=24&manufacturer_id=0&option=com_virtuemart&Itemid=46

This prop in a 21 pitch would be a starting place. You really need higher than that though IMO