does 15hp really make that big of a differance?

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B.L. Hall

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I have 60hp Evenrude on my boat that runs fine. I also have a 75hp Evenrude in my barn that hasn’t run in about 4 years.

Would that extra 15hp be worth taking the 75 in to the shop and get working properly to use instead of the 60?

It’s ratty old riveted 17’ Jon with a consol.

This boat is not a fast boat. Too much drag, too much weight, not a good prop… and I ain’t smart enough to “set up” the motor for optimum performance…

would the 15hp make that big of a differance for me?
 
In my opinion it would. I have a 25hp on my boat, and a buddy has a 40 on his, and it is a huge difference... 10mph faster easily.


Thats the only real world experience i can give you.


When are you coming home?
 
It depends. *The following is hypothetical as I realize there are no 240 hp engines available* If you have a 21' Ranger with a 225 hp Merc and a 21' Ranger with a 240 hp Merc, the difference in hp in terms of percentage is a little over 6%. A very minimal difference that would barely be noticed. However, in the example from Jim, he compares a 25 hp motor to a 40 hp motor. That's about 40% more horsepower, and you'd notice a considerable difference between those two motors on a comparably equipped rig.

In your case, by switching from a 60 hp motor to a 75 hp motor, you'd gain 25% more hp...a very significant increase that you'd definitely notice in the seat of your pants.

If your budget allows, I'd say go for it, but I think I saw where your boat was a 17', and I believe it's aluminum. It just seems like a 60 hp motor should push the typical 17' jon nicely. You may have motor problems, motor set up issues, or weight issues with your boat.
 
ibanez said:
It depends. *The following is hypothetical as I realize there are no 240 hp engines available* If you have a 21' Ranger with a 225 hp Merc and a 21' Ranger with a 240 hp Merc, the difference in hp in terms of percentage is a little over 6%. A very minimal difference that would barely be noticed. However, in the example from Jim, he compares a 25 hp motor to a 40 hp motor. That's about 40% more horsepower, and you'd notice a considerable difference between those two motors on a comparably equipped rig.

In your case, by switching from a 60 hp motor to a 75 hp motor, you'd gain 25% more hp...a very significant increase that you'd definitely notice in the seat of your pants.

If your budget allows, I'd say go for it, but I think I saw where your boat was a 17', and I believe it's aluminum. It just seems like a 60 hp motor should push the typical 17' jon nicely. You may have motor problems, motor set up issues, or weight issues with your boat.

Thanks Ibannez! :beer:
 
ibanez said:
If your budget allows, I'd say go for it, but I think I saw where your boat was a 17', and I believe it's aluminum. It just seems like a 60 hp motor should push the typical 17' jon nicely. You may have motor problems, motor set up issues, or weight issues with your boat.

It seems very heavy to me…. I am “considering” a new jet boat, but we will see on that.

I am not happy with my boat at all. This is my first boat. I bought is off my neighbor just before I deployed. My buddy and I have spend a lot of time in a canoe and I thought this would be great for us and I could take the wife out once in a while too…

All that is right, but with two of us in the boat, it just seems very slow. My brother-in-law has a 14 V with a 9.9 that seems faster than mine.

I am just not sure what to do about it. The motor “seems” to run fine. I will take the 75 into the shop when I get back and ask them to set it up on the boat.

I also… the plan was when I got the boat… was to re-deck it. There are a couple of soft spots and the carpet is ripped and mismatched. Once I took the boat out I was so disappointed with the performance I kinda lost interest in re-decking it.

I think I will strip it all out down to the haul and they take it out and see if it was the weight of the decking…

On another subject… my bud suggested that I get a jack plate, a water intake re-location kit and a prop made to run shallow…. There are a lot of rocks and shallow spots…
 
Bill, first thing be safe and get home soon, you have some great fishing in the ft drum area, be sure to look up burnie heaney when you get back he works with the mmr section. A jack plate should help get the bow up out of the water and give you more lift. As far a s a prop for running shallow I haven't seen one that can take a hard hit and still run true
the 75 should help

Wayne
 
Wow! Sounds to me like you probably have some weight issues with some rotting plywood (which I'm not a fan of in any boat...particularly in aluminum boats), and you may well have engine problems as well. I just can't see that some plywood on the decking could make the thing too heavy to perform at an acceptable level. How old is the boat and motor?

Here's a general rule of thumb to use when determining how much hp will perform at optimum levels in relation to weight of the boat. The equation is 1 hp per 25 lbs of weight in the rig (counting gear, motor, passengers, etc.) For instance:

Dry hull weight: 500lbs (probably pretty close)
Motor weight: 250lbs
Your weight: 200lbs (sorry :oops: )
Trolling motor weight: 50lbs
TM battery: 50lbs
Gas: 50lbs
Gear: 60lbs
Plywood: 75lbs

Total: 1235lbs

Using the equation of 1 hp per 25 lbs of weight, you need 49.4 hp at the head to make this rig perform like it should. You have 60 hp, so that SHOULD be enough.

I suspect your problem has to do with the motor or a combination of motor issues, weight DISTRIBUTION, and/or hull damage. Are there any large dents in the hull? Believe it or not, dented hulls can have a big effect on whether or not a craft can even plane off. Also, weight DISTRIBUTION is about as important as amount of weight onboard. You don't have most of your weight on the front of the boat do you?

Sorry for the long post...I'm just going over things in my head that I've seen that negatively effect hull/motor performance.
 
P.S. At some point you'll have to weigh whether or not the cost/trouble of repairing your rig is worth it. You mentioned looking at jet boats, and as a jet boat owner, I can tell you I love mine, and it's worth every penny spent. I'm tighter than bark on a tree, but I haven't regretted that purchase one single time.
 
B.L. Hall said:
I also… the plan was when I got the boat… was to re-deck it. There are a couple of soft spots and the carpet is ripped and mismatched.
Though I can't tell for sure, I think this may be your problem. If the plywood decking came from the factory, it will probably have flotation foam as well. And, though I don't know the age of your rig, you mention it being a "ratty old boat" and in the 70s and early 80s it was quite common to use an open cell flotation foam, instead of the closed cell stuff. That open cell stuff could absorb so much water, and in some cases, could double the boats weight. Now, you mention that the plywood has some rot in it. Rot doesn't happen quickly. The water has to touch it for long periods of time, and if it did that then there is a good chance it got to the foam first.

The 60 to 75 may or may not be a worthwhile expender. With many of them from the 70s and 80s, the 60 was a 2 cyl, and the 75 was a 3 cyl. One of the strongest, and best designed 75 ever made. That extra cylinder will account for a bit of extra weight, which some aluminum boats don't take too well too. But, if your boat is a mod vee, then it really would be fairly close to an aluminum bass boat, which a 17 footer is commonly powered by a 75 or more, and many 17 - 18 footers can hold the weight of a V4 with ease.
 
I did a search…

https://bunnell.olx.com/17-foot-john-boat-2000-iid-3116610

This is like my boat (this isn’t mine) but it’s the same kind except mine has two livewells under the seats and the front deck is just about a foot higher than the floor where the seats are…. other than that, it looks just like it…

There are no dents in the haul on mine, the only repair I did. I used Gluv-it and covered the rivets that appeared to be leaking.

Mid 80s for both the boat and motor I’d guess.

I had big pland on the redecking… I was thinking about a bigger motor too. I like a center console I can stand up at and steer. This would help in the river. Any suggestions on that? Can I move the console forward 2 feet and to the center or would that screw up balance to much?

I am really hopping it is the foam that is weighing id down. And I can get this thing going.
 

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