# Transom HP rating vs. Jet motor



## rotus623 (Dec 14, 2016)

Hey guys just wondering what you would do in this case.

My 1648 calls for a 50hp engine. Obviously if I got a 50hp powerhead and put on the jet foot I'd have 35hp. I'd like to put on a 60/40 or even a 75/50. I am aware that most engines (even factory jets) still have the powerhead HP in the model number.

My insurance company says they rate it on top speed of the boat, and unless you are stupidly overpowered they would not have any issues insuring the boat through any mishaps. What size engine would you guys recommend? Thanks!!


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## Ozark River Runner (Dec 14, 2016)

I have a 2015 60/40 Mercury Jet and I really like it. It is currently on a 1752 but my prior boat was a 1644 Alweld and I had no issues with that boat/motor combination. I would think that motor would be great on your boat. Most factory Jets will have the horsepower rating at the jet on the back of their motor. If you get a motor that is not a factory jet you could always just change the horsepower decal on the back. In my part of Missouri I have never had an issue with horsepower ratings nor do I have to deal with horsepower restrictions on the water I fish so I don't have any experience there. In my completely unprofessional opinion if the boat says its rated at 50 hp, I would be fine with putting a jet that is pushing 50hp at the pump. If you go with something as big as a 75 hp motor just compare the weight of that motor to others and make sure your transom can support it.


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## rotus623 (Dec 14, 2016)

Ozark River Runner said:


> I have a 2015 60/40 Mercury Jet and I really like it. It is currently on a 1752 but my prior boat was a 1644 Alweld and I had no issues with that boat/motor combination. I would think that motor would be great on your boat. Most factory Jets will have the horsepower rating at the jet on the back of their motor. If you get a motor that is not a factory jet you could always just change the horsepower decal on the back. In my part of Missouri I have never had an issue with horsepower ratings nor do I have to deal with horsepower restrictions on the water I fish so I don't have any experience there. In my completely unprofessional opinion if the boat says its rated at 50 hp, I would be fine with putting a jet that is pushing 50hp at the pump. If you go with something as big as a 75 hp motor just compare the weight of that motor to others and make sure your transom can support it.



Thanks for your input. I agree, I am totally comfortable with going by the power of the pump. Most of these motors at that HP range weigh the same. Glad to hear the 60/40 runs like you want it to. I have a VERY nice 60hp just up the road from me that I want to look at. The merc 40/50/60 2 strokes are 59 cubic inches!!! The evinrude 40/50 2 strokes are 44 cu inches, and the 3 cylinder 70/75's are 56 cu inches. So the merc 40 has more displacement than the evinrude 70hp!!!! (This is all 80-90's era)


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## Ozark River Runner (Dec 15, 2016)

A friend of mine has a 40/30 Johnson 2 stroke jet from the mid to late 90's I believe and its on a 1648. The 1644 I was referring to was a boat I bought off another friend of mine. He ran a late 90's to early 2000's Mercury 40 hp. This was a bigfoot 40hp prop motor that he put a jet on. I have fished and gigged out of both of those boats for several years are they are good set ups. I have always liked the Mercury 60 hp 2 strokes. I looked pretty hard for one that was in good shape before I decided to just buy new.


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## rotus623 (Dec 15, 2016)

I hear ya, they are hard to find in great shape. I like the Merc 60's because of the 59 cubic inch block. I love evinrude but the 2 cylinder 50 hps are only 44 cubic inches. I want as much power as I can get!!! But I think I would be okay with a 50/35 if I ran across a good one!


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## stinkfoot (Dec 15, 2016)

I have a Merc 40/30 on my 16 foot jon. Definitely wish I had 40 at the pump although it goes pretty quick when I put the prop leg on.....


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## rotus623 (Dec 15, 2016)

stinkfoot said:


> I have a Merc 40/30 on my 16 foot jon. Definitely wish I had 40 at the pump although it goes pretty quick when I put the prop leg on.....



What year Merc do you have? Most of the 40's can be easily converted to 50 hp's (and to 60's with a little more work). Would be an upgrade definitely worth trying!!


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## stinkfoot (Dec 16, 2016)

It is a 1977 402.


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## rotus623 (Dec 17, 2016)

stinkfoot said:


> It is a 1977 402.



What is the 402? Do you have a serial number?


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## lckstckn2smknbrls (Dec 18, 2016)

rotus623 said:


> stinkfoot said:
> 
> 
> > It is a 1977 402.
> ...


I have a '73 402. I'd like to know about HP upgrades.
Merc numbered their motors as to hp but some of the number were kind of odd.
The 110=9.9hp, 200=20hp, 350=35hp, 402=40hp, 500=50hp ect ect.
Why 402 I don't know.


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## rotus623 (Dec 19, 2016)

Gotcha.

Im not too sure about those motors. Do you have a serial number? Is it the 2 cylinder or 3 cylinder.


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## Lil' Blue Rude (Dec 19, 2016)

rotus623 said:


> Gotcha.
> 
> Im not too sure about those motors. Do you have a serial number? Is it the 2 cylinder or 3 cylinder.


Could be wrong but I think they're 4 cylinder crossflow motors with 2 carbs.


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## JoshKeller (Dec 20, 2016)

speed difference between a stock omc 50/35 and a 70/50 is approx 3.5 mph. the 70/50 uses the same exact pump as the merc 60/40


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## stinkfoot (Dec 22, 2016)

rotus623 said:


> stinkfoot said:
> 
> 
> > It is a 1977 402.
> ...



Sorry, been away. 402 is a twin as the name suggests. Serial number is 4726855 although that could be my parts motor as the number is on my phone. That one is a '75.


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## Crazyboat (Jan 12, 2017)

To the OP, better get that in writing from the insurance company.


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## rotus623 (Jan 25, 2017)

Crazyboat said:


> To the OP, better get that in writing from the insurance company.



Yea no kidding!!!


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