I got the old motor bug.

[1stgenbird]

I have a '57 18hp Fastwin that runs great but I want to get something a bit more powerful for my 14' aluminum. I saw a '55 25hp Bigtwin for sale and I am considering taking a look and possibly picking it up.
Is it worth upgrading for such a small hp gain or should I look for a '56 to '59 30hp or 35hp Bigtwin?

 

[watergecko]

Re: I got the old motor bug.

That's no small jump! what is that, like 40% increase over base power? i have a 14ft aluminum, and i upgraded my 15 hp to 25 hp. My speed went from 17 to 30! Granted i went from points to electronic but....ya. 2 things to consider though 1) what weight/hp is your boat rated for? Those oldies but goodies weigh alot! 2) are you ok with doubling or tripling your fuel burn? Just thoughts.

 

[1stgenbird]

Re: I got the old motor bug.

My boat can take up to 35hp so no problem there. Fuel burn still would be reasonable, I think.

 

[levi_tsk]

Re: I got the old motor bug.

if you can find one id do it -i dont think the big twin weighs that much more than a fastwin my fastwin is 70ish lbs and id put a bigtwin at around 90 -they arent NEARLY as heavy as a modern fourstroke ....
id shoot for another 57 or a 56 -best color schemes if you ask me

 

[samo_ott]

Re: I got the old motor bug.

That's good you have the old engine bug. I have all the engines you listed. The 18's are awesome engines. Will this be a tiller setup or remote? What kind of boat is it? The 18 to 25hp increase will gain a little speed but a lot of torque as you really boost the engine size. The 18 is a 22 cubic inch block and the 25/30 is the 35.7 cubic inch. The 35 is a big bigger again. Speed and power are always nice but it will cost you in fuel. So it really depends on your setup and what you want to do with it.

 

[1946Zephyr]

Re: I got the old motor bug.

An 18 would push any 14' aluminum boat quite nicely. If not, then your motor may not be running top notch. And truth be known, the later motors really aren't any lighter than the oldies. A 1957 18 is only a few pounds more than the modrn day 2 stroke 15. The powerheads have got a little lighter, but they made the lower units bigger. A 1957 Fastwin is approximately 75 - 78 pounds, stripped down, without a starter and a modern 15 two stroke model is pretty close to the same. Now if you go up to one of the old 25/30's, you'll start at 112 pounds for a stripped down model and with a starter, you'll go 126+ pounds. Now, lets add an operator, a full tank of gas (with a 25, might add two) your fishing gear, all the required safety equipment, a cooler and your best friend,, your weight will add up quickly.

So, if you want to go to a 25, without adding any extra weight, compared to your 18, then get a 1969 - 76 25 hp and your weight will stay the same. The 25's that were built later than 1976, were the bigger 31.8 cube motors and there again, they're heavier.

 

[1stgenbird]

Re: I got the old motor bug.

To me, weight difference in the motors is not an issue since my '64 Starcraft 14 footer is rated up to a 35hp.
However, when I refer to old motors, my preferences are the outboards from the mid-50s into the 60s. I'm not too keen on the later models. When I do see those later years for sale around here they command a price higher then I want to pay; $600 - $1200.
Typically I see the 50s and 60s on the block for $100 - $400, depending on hp and condition. Those prices I don't mind (I'm cheap). Plus they are easy to work on for the most part.
I use a tiller model so the bigtwins with tillers are a bit more difficult to find as most seemed to be remotes.
The '55 bigtwin I may be taking a look at is a tiller. The seller also has some '56 - '59 bigtwins so I will be checking those out also.
Well, not the '59 as I think that year Rudes are so ugly I wouldn't own one.

 

[tallcar]

Re: I got the old motor bug.

I own the same boat, a 35 on that would be a wild ride, I can assure you. I think the early 70's 25 hp, they will make that boat scoot.

 

[1946Zephyr]

Re: I got the old motor bug.

the '55 Big Twin is an awesome motor. In this case, if you stepped up to the 30, you won't have a difference in weight. The 35 from '57, may not be any heavier either. The '59 35 is considerably heavier than the '57, simply beacause of all the Super Quiet suspension.

I'm like you, I prefere the motors of that era myself, mostly for the same reasons you do I have a '59 Johnson RDSL-21B, thats going to get a deep hull fiberglass, plus I own a couple old 5 1/2's from '55 and '58.