Let's Talk Big Twin/SpeediTwin

[Bwana Don]

I need some advice. I'm looking for a motor for my 14' rowboat. It's a pretty wide one at 62". Deep too, the transom is 16'' I believe. Short shaft anyway. I'm guessing the Sea Nymph is rated for a max of 25 hp. I'm on a tight budget as usual. I keep finding these boats (old glassers) with good trailers I want and old motors attached. I need an education on these old Johnson Big Twins.

I see a 1952 Johnson 25 hp and a 196? Speeditwin 28 hp I could probably pick up. Pull the motor salvage said trailer and scrap the old glass boat.

The 28 hp Evinrude is a long shaft no tiller. I need a short shaft and a tiller. What do you think?

The 25 hp is a Johnson 1952 or '53. From the Cl add it looks like it's NOT a tiller. Is that a big deal to convert to tiller? Are the pre '55 Big Twins easy to work on, reliable etc? Hard to pull start, heavy....

Follow my Sea Nymph link at the bottom of my signature and you can see pics. Any help is appreciated. I do have the book "Cheap outboards" by Max. I've scoured the net, done my homework and now I'm ready to talk to actual owners of these motors.

Thanks
Don

 

[kfa4303]

Re: Let's Talk Big Twin/SpeediTwin

Hi Bwana. I would go with the 60-something 28 hp. While generally good motors, pre-1955 OMC motors can be pretty hard to find parts for, but the late 50s-mid 70s era motors are light weight, reliable, easy to work on and have many interchangeable components between model years and hps. The weight difference between the 25 hp your boat is rated for and the 28 hp you're looking at should be negligible as well. You can also easily convert it to a tiller and/or controls. However, being a long shaft, you may have to raise the motor a few inches to get it to the optimum height, but that's no big deal. Once you have it dialed in it would probably push you along at around 25 mph. Big Twin motors are awesome, easy to maintain with lots of low end torque, but they do eat gas :/ However, for their weight you can't beat the power they make, and the 2-stroke zippyness is great. Some of the best were the 18hp-40hp models. They come in both pull and/or electric start versions. While the +30 hp models can be a bit of a bear to pull start, the rest are pretty easy. My '66 20 hp stars in 1-2 pulls every time and will run all day on 3-4 gallons while pushing me in my 14' tinny at about +20 mph. Assuming the compression is ok on the motor, all the rest can be fixed pretty easily. Happy hunting. Keep us posted.

 

[HighTrim]

Re: Let's Talk Big Twin/SpeediTwin

Here is my advice. Buy neither of them.

The reason? If you dont already have the parts motors with the parts necessary, you will be spending more on tillers and short shaft conversions than they are worth at the end. I mention this due to your budget. These 50s omcs are plentiful, wait it out a bit, keeping an eye on the classifieds over the winter and get a motor that will work for you from the start that is already short shaft and already has a tiller.

 

[Willyclay]

Re: Let's Talk Big Twin/SpeediTwin

OMC motors built in 1964 and later use 50:1 gas/oil mix which will produce less smoke. Full synthetic oil will help even more. Good luck!

 

[kodibass]

Re: Let's Talk Big Twin/SpeediTwin

I think & the pro's on here can confirm, the evinrude 25 twin 1954 & earlier tiller needs a bit of a different magneto plate because it is a wire pulley kind of deal, I had a 1954 I gave to a friend and I know that's what it had, x2 on post 2.

 

[Bwana Don]

Re: Let's Talk Big Twin/SpeediTwin

Thanks for the reply's guys. You have me sold on the nothing before 1955. I've seen a couple of early 70's motors out there. A little more money though and none are tillers. I also see a bunch of AquaSonics, 18 hp in the $350-$450 range.

I want to get my ducks in a row in case something comes up between now and late winter. That way I'll pull the trigger without hemming and hawwing. Plus I'm addicted to CraigsList.:facepalm:

 

[1946Zephyr]

Re: Let's Talk Big Twin/SpeediTwin

Yes, an 18 would be a great choice and use less gas than the old Big Twin and SpeediTwin. 1957 and '58 are the best year 18's built and all the consumable parts will be available for years to come, because they took the same parts as the motors up to 1976.

 

[kfa4303]

Re: Let's Talk Big Twin/SpeediTwin

+1. If you can hold out for an 18 hp/20 hp, it would be well worth it. They're they best pound-for-pound, bang-for-your-buck motors you can get, and the '58 models are SWEEEET lookin'

 

[Bwana Don]

Re: Let's Talk Big Twin/SpeediTwin

Ok on one hand I've got a 25 hp Johnson circa 1955. The other holds a.....'58 18 HP Johnson or Rude.

Which hand do you recommend. I'll slant my search for a motor in that direction.

Thanks for the great info guys.
Don

 

[1946Zephyr]

Re: Let's Talk Big Twin/SpeediTwin

Get the 18. It's a better choice for a 14' stern drive boat. The Big Twin class is just too heavy. A 1955 Johnson 25 would be nice on a 13 - 14' fiberglass runabout with remote steering and controls.

 

[kfa4303]

Re: Let's Talk Big Twin/SpeediTwin

+1. That '58 18 hp is a dream machine! One of the best pound-for-pound motors ever and super cool looking to boot. I have a '66 20 hp, which is essentially the same motor and it's super reliable and pushes me along a +20 mph in a 14' semi-v hull tinny. Mine has the no so stylish, whit e fiberglass cowling, but the '58s have that sweet reverse two tone paint job. Here's a handy link.

Maintaining Johnson E & FD Serie

 

[Bwana Don]

Re: Let's Talk Big Twin/SpeediTwin

Great advice here. kfa thanks for the link. Leroy sure has a lot to say. It's pretty good stuff to. That will come in handy when I get an 18 hp.

Thank a bunch guys. This winter one will pop up in my price range and I'll snag it. Just have to make it through Christmas.

 

[kfa4303]

Re: Let's Talk Big Twin/SpeediTwin

You can't go wrong with any of the FD/E model motors up until the early-mid 70s, when they changed to electronic ignitions and things got a bit wonky. If you do find a '58, or any pre-'59 model, remember that it does NOT have a fuel pump so you'll need a 2-line pressure tank to go with the motor. Of course, you can always convert it to a fuel pump later, if you want to. The post '59 models did have a fuel pump, so you can use a modern single-line tank with regular OMC fittings. Happy hunting. Keep us posted.

 

[64osby]

Re: Let's Talk Big Twin/SpeediTwin

BD, I'll say +1 on the 18hp.

Here's a link to a vid on the 14' Lone Star with a 57 Rude 18hp.

Lone Star 14 Big Fisherman 1963 :: Lone Star Non Leak Test video by 62iia - Photobucket

 

[popsmazz1]

Re: Let's Talk Big Twin/SpeediTwin

I have a 52 25hp. big twin tiller if you are interested, runs, good shape, I live in your area

 

[jay_merrill]

Re: Let's Talk Big Twin/SpeediTwin

The early 60s 28hp is an outgrowth from the early/mid fifties 25hp and 30hp engines. There are, however, some differences that relate to parts availability. One is the clutch dog - my local OMC/BRP dealer once told me that they are extremely hard to find for the '56 and older motors. Parts for the 60's 28hp and 33hp (basically the same engine) are still surprisely easy to find.

The conversion from remote steer to tiller steer is easy, except for one thing - finding a tiller handle. I happen to have one off of a 58 ERude Bigtwin and I wouldn't part with it for a lot more money than it is worth. The reason why is simple - I know how hard they are to find and I have a couple of Johnson 33s and want to be able to make one a tiller steer (the Bigtwin part fits the later motors).

I agree with Hightrim. I would be patient and find a motor that meets your needs from the start. Don't forget that there are some 70's vintage 25hp motors that would be perfect for you. Even though the later motors might have stators and powerpacks for ignition (as opposed to points/coils), they are still simple and very reliable outboards.

 

[Bwana Don]

Re: Let's Talk Big Twin/SpeediTwin

Thanks for the offer Pop but I'm going to go for a post 1955 outboard.

64osby that looks plenty fast with the 18 on her.

jay, what's the weight difference between the 18 and 25? I'm going to guess 120 lbs for the 25 and 80 lbs for the 18.

KFA, I've got a Mikuni fuel pump for a QD-16 that I bought for a kicker to use on the 18' Starcraft that I've not finished yet. Plus I've got instructions on how to do it. I'm not crazy about the pressure tanks.

Thanks
Don

 

[jay_merrill]

Re: Let's Talk Big Twin/SpeediTwin

Your probably about right on the weights.

 

[Willyclay]

Re: Let's Talk Big Twin/SpeediTwin

I'm going to guess 120 lbs for the 25 and 80 lbs for the 18.

Good guessing! The factory manual at the link below says 110 and 77.

Boatinfo - 1922-1964 Johnson Service Manual

 

[1946Zephyr]

Re: Let's Talk Big Twin/SpeediTwin

Yep, another good reason to go with an 18 or 20, versus the Big Twin typ 25. Now, a 1969 or later 25 would be a great choice too, because they are the 22 cube model, like the 18's and 20's and equally as reliable.