Weight difference between 1970's 45HP and 70HP?

Joined
Oct 6, 2010
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17
I have finally accepted that mt 45HP is not salvageable. I have located a 70HP for a decent price, however my concern is the difference in weight. The boat is only 14' so a huge weight difference seems like it would be an issue.

Anyone have any input?

Thanks in advance.
 

Frank Acampora

Supreme Mariner
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Jan 19, 2007
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12,004
Re: Weight difference between 1970's 45HP and 70HP?

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Here is a 14 footer with a 90 and 125 on it. The transom is narrow so she sits low in the water. HOWEVER, I have had 3 people in her and we were water skiing. SO, if your boat is rated to take a 70, weight may not be that much of an issue. You will, however, find a major improvement in performance over your 45.
 

MickLovin

Master Chief Petty Officer
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Feb 18, 2013
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Re: Weight difference between 1970's 45HP and 70HP?

I came up with around 123lbs difference, the 85hp chrysler is 275lbs, but as pnwboat I couldn't find the weight of a 45hp chrysler so I went with him on the force 50hp, the force 50hp is also one of the lightest. Pnwboat is right it gives you an idea, I had a 115hp on my 14.5ft but it was a ski boat designed for it.
 

Frank Acampora

Supreme Mariner
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Jan 19, 2007
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12,004
Re: Weight difference between 1970's 45HP and 70HP?

If it is a Chrysler 70, it will be the same weight as the 85: Around 275 lb. If it is a Force 70, since it uses a smaller lower unit and midleg, it will weigh less than the Chrysler--probably about 35-50 lb. lighter so figure about 230 or so lb.
 

MickLovin

Master Chief Petty Officer
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Re: Weight difference between 1970's 45HP and 70HP?

I knew the encyclopedia of Chrysler and force outboards would chime in soon :D
 
Joined
Oct 6, 2010
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Re: Weight difference between 1970's 45HP and 70HP?

Thanks for all the quick replies. I just got back from looking at the motor. That 70HP motor looked HUGE compared to my 45HP. I didn't realize that it also has a hydraulic tilt, which I am assuming adds more weight.

My boat (1978 Del-Magic Colt) is only rated for up to 55HP. I wasn't really trying to ignore that number for performance gains, I just want a damn motor on my boat. :) That said, I am really concerned about the additional weight. If she dips a bit lower in the back, my troll motor may breach the surface easier and it will most likely make it harder to fish the shallower (unless I use the hydraulics to raise the motor).

I'd hate to pass up this motor if it would work, but my gut is telling me it is too much motor for the boat and I should look for a 50-55 HP. Am I way off here?
 

pnwboat

Rear Admiral
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Oct 8, 2007
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4,251
Re: Weight difference between 1970's 45HP and 70HP?

If your boat is rated for a 55HP motor, then you would have to add some reinforcement to the transom. Only other issue would be if the water patrol notices that you have an "over powered" boat. Not sure how the laws in your state are, but it's something that may come into play. The 70HP motor will also use more gas than your 45HP.
 

MickLovin

Master Chief Petty Officer
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Feb 18, 2013
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822
Re: Weight difference between 1970's 45HP and 70HP?

If the 70hp is a good motor compression is good I believe 140 - 150 psi is good for a 70hp, then buy it and sell it on after you clean it up a bit, or trade it. I have a 100hp on my 115hp rated boat, I find the 100hp is way more than enough weight but in my case a 115hp wouldnt way to much more, in your case it is going to make a big difference as you are going more than 20% above the boats capacity. Why not try and find another 45hp then you would have a parts motor, not sure what you mean by salvagable, if it was down on compression I would accept that, as firstly I wouldn't repair it, it's just not my thing, but if it is just not running correctly and had good comp, I would spend the time to repair it if it killed me LOL.
 
Joined
Oct 6, 2010
Messages
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Re: Weight difference between 1970's 45HP and 70HP?

Why not try and find another 45hp then you would have a parts motor, not sure what you mean by salvagable, if it was down on compression I would accept that, as firstly I wouldn't repair it, it's just not my thing, but if it is just not running correctly and had good comp, I would spend the time to repair it if it killed me LOL.

I would LOVE to keep my current engine. The boat was my grandfathers and I am sentimental to a fault about his stuff . However, the compression is bad 60/120 after it overheated. And apparently, they do not make pistons for it anymore.

I was hoping to at least keep it a Chrysler so it would stay somewhat true to form. Am I correct in assuming that buying another Chrysler motor would allow me to retain my current controls? Or is that just wishful thinking?

Thanks again for ya'lls input.
 
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