What motor size?

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

What motor should I get

  • 15hp 2 stroke

    Votes: 0 0.0%
  • 20hp 2 stroke

    Votes: 3 13.6%
  • 25hp 2 stroke

    Votes: 13 59.1%
  • 15hp 4 stroke

    Votes: 0 0.0%
  • 20hp 4 stroke

    Votes: 1 4.5%
  • 25hp 4 stroke

    Votes: 5 22.7%

  • Total voters
    22

grummanguy

Member
Joined
Sep 17, 2016
Messages
7
Reaction score
0
Alright I'm sure you guys are used to answering these kind of questions. I recently picked up a 88 Grumman 14' v hull. Any one from the Long Island, New York area is probably more familiar with this particular brand of boat but anyone can help answer my question.

I got it without a motor and threw my 5hp johnson 2 stroke on the back to see what it would do. With me in back about 200lbs and my friend in the front about 140lbs we did 13mph in the choppy bay. With him in the middle row we did 6mph. This is all as per GPS on my phone.

Now I'm looking for a bigger motor and I'm hoping with this information you can all give me an estimate on what motors will hit what speeds. At first I was thinking a 15hp would be nice but the boat can handle a 25 according to the capacity plate. I'm definitely thinking 2 stroke just because of how much lighter it would be on the transom than a 4 stroke? So what does everything think 15,20,25? 2 stroke or 4 stroke?
 

Attachments

  • IMG_8181.JPG
    IMG_8181.JPG
    78.9 KB · Views: 1,588
  • IMG_8183.JPG
    IMG_8183.JPG
    62.1 KB · Views: 1,588
Unless you are fishing places with horse power limits, I would get the biggest motor your boat is rated for. You can always go slower. But you can't go faster or get on plane quicker with a smaller motor.

Sent from my XT1030 using Tapatalk
 
I picked the 25 4s just because. IMO it doesn't matter much 2s or 4s but I couldn't pick 2 options.

I had a 15 2s as a kid and we used to water ski off of her and run about 25 MPH calculated.

Go with the 25, you can always back off the throttle but you will need it if you go out with gear and a 3rd person.

If weight of an engine is an issue for you Lifting/carrying etc a 15 2s is the minimum option.
 
I voted 25hp 2stroke but don't pass up a good 30hp if you find one.
 
I had a 13 ft. Duranautic which is similar. It weighed about 160 lbs (boat alone) . With a 15hp Yamaha 4-stroke I was getting about 29mph with just me in the boat. With 2 aboard I got about 24/25. The boat had a 50 lb battery and 15 lb trolling motor aboard also.

A 15 is going to get you up to a reasonable speed. I think the 25 is overkill. That boat was designed before the 4 strokes came about. 4-strokes are heavier than older 2 strokes. IF you are going t the max motor rating it should be an older 2 stroke. If going 4 stroke go a size smaller.

I am in Jersey...........
 
Thanks everyone for the replies. sonny.barile what you said is just what i was thinking. I think a 25hp 4 stroke will be too heavy for the back. But if I can find a 25hp 2 stroke that would be the ideal option I think based on my own judgement and the input of this forum. Another question I have is at what speed in a 14ft v hull does it become unsafe? Someone said they did 29mph with a 15hp. Id imagine with a 25hp I could do maybe 34ish, I think that sounds right. Is that too fast, obviously i wont be making any crazy turns and I wont be running flat out very often but I'm just curious what everyone else would be comfortable with.
 
I voted 25hp 2 stroke...but honestly, Id say get what you can afford and what's available. A 15hp will get the job done and will cost less. Also, now is the time of year you may can haggle more as lots of sellers are trying to get rid of their stuff before it gets cold and they have to winterize it.
 
Grummanguy

I know that boat model well. I grew up in Jersey and there are tons of them still around. Thats a testament to how well they were made.

That boat with a 2stroke 25 will probably hit around 28/30 It isn't the turns that will get ya. These boats are v bottomed in the bow but tend to flatten out a bit in the stern. It will beat the crap out of you running against the tidal current wide open. In my 13 footer I had to slow it down with any kind of wind over tied. All that pounding beats the crap out of your transom and your back.

However, the extra speed is nice to have when it kicks up and you want to get the heck out of there.
 
wmk0002 good call on it being the right time of year to be a buyer

sonny.barile I knew somebody around here had to have some experience with this exact boat thanks for the info. Luckily I'm still young so I dont mind getting the crap beaten out of me.

Most likely I'll be looking for a 25hp 2 stroke but if I find a 15hp first I'll take it if the price is right. Its upsetting I didnt think it would be hard finding a motor for this hull but I'm having trouble finding anything worth buying right now.
 
my 25 horse 4 stroke moves my 1000 lb. boat up to 25 mph with a 12 pitch prop.i traded it at the dealer from a 14 for slower trolling speed so i probably lost a couple mph.i was limited as to what i could get in a short shaft with electric start and power trim/tilt in a 25.i really wanted the e tec but settled with a tohatsu and so far i really like it.
 
I have a 1448 flat bottom and it originally came with a 9.9 4s, it was a heavy azz motor. I wanted to upgrade and was going to go 4s again. I was pretty much set on Yamaha only because I could get one at a good price new. I looked at the 15 to 25 hp and realized that the 15 and 20 were the same motor, same weight everything just one had 5 more hp. The 25 however was a much heavier motor and bigger too, for me it was a no brainer, the 20. I doubt the 25 would give me much better performance especially considering the extra weight which was important to me to keep the boat skinny.
 
Alright guys I just secured a 2000 Mercury 15hp 2 stroke. Should be light but still pack some punch hoping to hit high 20's alone and hopefully 20+ with 2 passengers.

I'll be testing it soon if this bad weather ever lets up I drove 4 hours and a few states over to get so I'm for sure excited.
 
Here she is in all her glory can't wait to run it!
 

Attachments

  • IMG_8346.JPG
    IMG_8346.JPG
    101.5 KB · Views: 1,294
Nice Motor
Don't be disappointed if you don't hit the high 20's. I could only hit 28-29 mph with 25 or 30 hp motors on a 15' boat. I got low 30's with a 40hp motor. My boat is heavier because its decked out but still..... You will hit low 20's and maybe 25 mph if the wind and current is right.
 
Whoopbass said:
Nice Motor
Don't be disappointed if you don't hit the high 20's. I could only hit 28-29 mph with 25 or 30 hp motors on a 15' boat. I got low 30's with a 40hp motor. My boat is heavier because its decked out but still..... You will hit low 20's and maybe 25 mph if the wind and current is right.

Nice motor and I agree with what was said above. I've got a 15hp Johnson myself on a 1648 and I get about 21-22 mph solo with the factory sized prop. With a lighter boat turning a few more rpms and having very little prop slip 25 mph is about the theoretical max my motor could achieve.

If you want to prop it just right you will need a tach and if you want to calculate prop slip and toy around with some theoretical top speeds you can use the link below. You just need to find your drive ratio to use as an input.

https://www.rbbi.com/folders/prop/propcalc.htm
 
I appreciate the link I may look into getting a tachometer in the future to play around with a different prop but first day out I got 25mph. Not bad I'm definitely happy with it. I'm just hoping when I throw a few decoys, ammo boxes, guns, and other gear, plus another person if not 2 that I can still get it to hop on plane.
 

Latest posts

Top