Should my boat get up on plane?

[greatoutdoors]

Hi guys, I have a 14' V hull with decks, seats trolling motor, etc., etc. I would estimate with 2 people and gear it weighs near 1200 lbs. I have a 15hp on the back. Should this get the boat to plane? It doesn't so I was wondering if the motor isn't pushing out all the hp or if it simply isn't enough to get it up on plane. Thanks.

[George Welcome]

No it shouldn't.

[fishfordollars]

Hi guys, I have a 14' V hull with decks, seats trolling motor, etc., etc. I would estimate with 2 people and gear it weighs near 1200 lbs. I have a 15hp on the back. Should this get the boat to plane? It doesn't so I was wondering if the motor isn't pushing out all the hp or if it simply isn't enough to get it up on plane. Thanks.

Nope, just too much boat, add ons, and people for that motor to push

[cato]

very doubtfull

[greatoutdoors]

Do you think a 25 horse would do the job?

[backpain...]

I have a 14' V aluminum myself. I have it decked with 2 deep cycle batteries, 2 Trolling motors and 2 220# guys. When I had a 25HP johnson it would flat out fly. The johnson had a freak issue with sucking in something into the impeller and died of overheat. I put my a 15HP Merc on there and the thing does get on plane, but barely. It just isn't the same boat.

[umahunter]

put as much motor as you can afford and float i aint never wanted less power

[Way2slow]

I'm wondering how you manage to have 1200 pounds if the boat, unless the people for three or four hundred pounds each.   If someone got carried away using too much and too heavy of material building those decks, I would consider a possible rebuild.

Before I did anything, I would check the pitch on the prop, it may be an 11 or 12 inch pitch prop, if so, drop down to a nine. The diameter and pitch should be cast into the prop just under the prop nut. I would also do a compression check, low compression will kill low end torque, which is what's needed to get up on plane.

[greatoutdoors]

I'm wondering how you manage to have 1200 pounds if the boat, unless the people for three or four hundred pounds each. If someone got carried away using too much and too heavy of material building those decks, I would consider a possible rebuild.

Before I did anything, I would check the pitch on the prop, it may be an 11 or 12 inch pitch prop, if so, drop down to a nine. The diameter and pitch should be cast into the prop just under the prop nut. I would also do a compression check, low compression will kill low end torque, which is what's needed to get up on plane.

I am estimating around 1200 which includes the decks, floors, both motors, big trolling battery, full tank of gas, a bunch of gear and two 225 lb men, not to mention the boat itself weighed around 3 beans itself--very heavy gauge aluminum. Will the 9 inch prop sacrifice top end speed? Don't care as long as it gets on plane, it just pushes water now. What if I had the other passenger move to the rear of the boat when accelerating to take off some weight from the bow?

[Fishing Rhino]

Weight toward the rear will not help.  It will just make it squat.

Once a boat is on plane, moving weight toward the stern will usually increase the speed, since it reduces the wetted area.

If the boat were flat bottomed, like a jon, you'd have problems getting it to plane at the weight you've stated, but it would get on plane easier.

More power is your solution.

[Way2slow]

What speed??  If you're plowing you have no speed.   If you don't already have a 9" prop, it would help, no matter what.  At 1200 pounds, the boat is so grossly overloaded it may not get up but the the smallest prop you can get (which I think is a 9" pitch) will certainly help by taking a lot of the strain off the motor and may actually run faster by letting the motor get up into a more suitable power band.

[greatoutdoors]

What speed?? If you're plowing you have no speed. If you don't already have a 9" prop, it would help, no matter what. At 1200 pounds, the boat is so grossly overloaded it may not get up but the the smallest prop you can get (which I think is a 9" pitch) will certainly help by taking a lot of the strain off the motor and may actually run faster by letting the motor get up into a more suitable power band.

I'm probably topping out at around 12-15mph. The boat actually isn't overloaded, it's right at capacity. The boat itself weighs 300 and the capacity with persons and gear is 880. I found i could get a 7" pitch prop. Would that be better than a 9" or would it be too much.

[Catt]

What speed?? If you're plowing you have no speed. If you don't already have a 9" prop, it would help, no matter what. At 1200 pounds, the boat is so grossly overloaded it may not get up but the the smallest prop you can get (which I think is a 9" pitch) will certainly help by taking a lot of the strain off the motor and may actually run faster by letting the motor get up into a more suitable power band.

I'm probably topping out at around 12-15mph. The boat actually isn't overloaded, it's right at capacity. The boat itself weighs 300 and the capacity with persons and gear is 880. I found i could get a 7" pitch prop. Would that be better than a 9" or would it be too much.

1200

-880

320 beyond capacity

[greatoutdoors]

What speed?? If you're plowing you have no speed. If you don't already have a 9" prop, it would help, no matter what. At 1200 pounds, the boat is so grossly overloaded it may not get up but the the smallest prop you can get (which I think is a 9" pitch) will certainly help by taking a lot of the strain off the motor and may actually run faster by letting the motor get up into a more suitable power band.

I'm probably topping out at around 12-15mph. The boat actually isn't overloaded, it's right at capacity. The boat itself weighs 300 and the capacity with persons and gear is 880. I found i could get a 7" pitch prop. Would that be better than a 9" or would it be too much.

1200

-880

320 beyond capacity

You are misunderstanding. I can put 880 pounds in the boat. The boat hull weighs 300. The capacity doesn't include the hull weight. That equals 1180. I estimate that it weighs 1200. I'm 20lbs over. I won't bring the 30 pack next time.

[Catt]

As per the United States Coast Guard 33CFR183.35 & 33CFR183.41 Subpart C_Safe Loading

http://www.access.gpo.gov/nara/cfr/waisidx_04/33cfr183_04.html

[Catt]

You should not exceed either the stated maximum weight capacity or the maximum number of people.

Maximum weight is the combined weight of passengers, gear, and motors.

[greatoutdoors]

Thank you for that. I can use it. I have to figure out a way to get some weight off the boat. I realize I am right at capacity, I have around 900 in the boat with 2 people and my capacity is 880, but I just need a little more power to get up on plane.

[Way2slow]

I would not guess if a seven inch pitch prop would be better or not.  I don't know what size you have now and how bad the motor is loading down.   All my 9.9's have been Johnson's and I've never run less 9 inch pitch.  My 87 9.9 with a 9" prop will plane a 1642 jon with a pretty good load in it.

If your motor is one of those off brands like a Game Fisher etc, it may never make enough torque to plane a heavy boat.

[greatoutdoors]

I would not guess if a seven inch pitch prop would be better or not. I don't know what size you have now and how bad the motor is loading down. All my 9.9's have been Johnson's and I've never run less 9 inch pitch. My 87 9.9 with a 9" prop will plane a 1642 jon with a pretty good load in it.

If your motor is one of those off brands like a Game Fisher etc, it may never make enough torque to plane a heavy boat.

It's a '53 Evinrude Fastwin. It has over 100 psi in both cylinders, a carb rebuild, new coils and impeller. It runs great. I didn't get a chance to check the propeller pitch yet. I'll let you know.

[Way2slow]

Now you've got me. I've never worked on a motor that old but those compression numbers seem way too low. I once had a 1965 18 hp fast twin and it had a compression of 135 pounds on each cylinder, and that was after it was 13 years old. The early model motors had a lot more compression than modern day motors because the cheap, regular gas back then was better than our best high octane we have now.

I'm not even sure what lower unit that motor has but I'm pretty sure I have an old 9" pitch prop (if I can find it) that fit my old 18 fast twin. I will give that one to you if it will fit. The 18 FastTwin was the same motor as the 25 Johnson back then so it would have to have that size LU. BRP parts only goes back to 1968 so I could not research it.

[Catt]

The problem you will find is the lower unit on the motor does have the gearing required for that weight and the props were not that aggressive.

[IMPY03]

I have the same problem with my 12 foot V with a johnson 9.9. I also have a deck, TM, battery, and a pretty good amount of gear and with 2 people I can't get on plane either and I'm guessing I'm getting around the same speed you are, it definently sucks when hitting decent size wakes.

[greatoutdoors]

Now you've got me. I've never worked on a motor that old but those compression numbers seem way too low. I once had a 1965 18 hp fast twin and it had a compression of 135 pounds on each cylinder, and that was after it was 13 years old. The early model motors had a lot more compression than modern day motors because the cheap, regular gas back then was better than our best high octane we have now.

I'm not even sure what lower unit that motor has but I'm pretty sure I have an old 9" pitch prop (if I can find it) that fit my old 18 fast twin. I will give that one to you if it will fit. The 18 FastTwin was the same motor as the 25 Johnson back then so it would have to have that size LU. BRP parts only goes back to 1968 so I could not research it.

Way2slow, I checked on Iboats and a 1953 fastwin 15 and a 1965 fastwin 18 prop are the same part number so it will work! That would be awesome if you would send that to me. Maybe we could get something figured out. Let me know. Had the boat out today with my son who is 75 lbs versus my farher in law's 225. Played around with the high speed knob and found a better spot in it where the motor gained a few rpms. It wanted to get up and plane but just fell a little short so I'm sure that prop would help. Obviously I will pay for the shipping if you could find it. Thank you.

[Way2slow]

I just ran into a problem.  Dug out the old 25 hp motor and there is no lower unit on it, which is where the prop was suppose to be.  I'm in the process off building another storage shed to move a lot of that junk to so maybe this weekend I will find the LU.  It has been so long, I may have given it away but I don't remember it, (of course as bad as I have  CRS that doesn't mean a thing).

[greatoutdoors]

I just ran into a problem. Dug out the old 25 hp motor and there is no lower unit on it, which is where the prop was suppose to be. I'm in the process off building another storage shed to move a lot of that junk to so maybe this weekend I will find the LU. It has been so long, I may have given it away but I don't remember it, (of course as bad as I have CRS that doesn't mean a thing).

Ok, well if you find it let me know. Thanks.