Best era for 30-40 hp Johnsons

Hi all. I'm looking to upgrade my trusty '66 20hp to something in the 28-40 hp tiller, 2-stroke range. Just wondering if any of y'all have any suggestions, or words of warning against, any particular make/model of OMC that fit the description. I'm a Luddite, so I love the old magneto ignitions, but I've heard that the electronic ignitions from the mid 80s-mid 90s models aren't too scary. While I am hoping to pick up a bit of speed by increasing the hp, I'm more concerned with reliability and ease of maintenance. I don't mind loosing a few mph/rpm, if it means I can do most of the work on the motor myself.

I don't mind looking outside of Johnson/Evinrude motors either. I've heard great things about 25-50hp Yamaha 2-stokes as well, but they're rarer than hen's teeth down here in FL and they command top dollar (over $2k for a decent 30hp), which I can't spend. After all, my 20hp was only $100 and came with a free parts motor. Are the 28hp OMC motors noticeable faster than the vintage 18/20hp models? Is it correct that "modern" motors measure their hp at the prop, rather than the driveshaft and are therefore more powerful than their vintage counterparts of the same hp, if so by how much? (i.e. is a modern 20hp faster/stronger than a vintage 20hp)?

Thanks for any input.

Re: Best era for 30-40 hp Johnsons

Well, the 28hp from the early 60's, is merely a "re-born" 1956 30hp. It still had the 35.7 cubes, so they will kick up some more speed. Then again, they're a bit heaver. Myself, if I'm going to get a tiller model, a '57 - '58 Big Twin 35 is a great choice, because those aluminum clamshell covers hold up so much better, when beaching your motor. You don't have a doggon fiberglass hood coming off in your hand.

Re: Best era for 30-40 hp Johnsons

I bought a 14' Lund aluminum boat with a 33hp tiller (Very similar to the 28) motor and was very disappointed in it. Sitting in the back with that heavy motor, I had choice of two speeds, slow and fast. It squatted like crazy till it got up on plane, then took off. There was no practical in-between at all. So I sold the 33 and put an 18 on it. Turned into a very nice boat. I still have the boat, but now have a 1984 Johnson 35 Remote Electric on it. Best rig I've ever owned.

Re: Best era for 30-40 hp Johnsons

i have a 72 20hp, upgraded the carb to 25hp. overall pretty happy, almost too much for my 14footer. figure this, 25hp 82 pounds. thats about 6 more pounds than a 9/15 but almost twice the power. jmho.
dino

Re: Best era for 30-40 hp Johnsons

Mid 80s -90's OMC 25, 30, 35 hp, basic tiller motors all weight the same I think? a bit more for long shaft, less for shorts. One nice feature I know that came out around 1990 was the shifter in front instead of the side, so you don't have to reach around to place in gear. Also I like the positive primer system over the older flapper choke, As far as ignitions go I like the CDI with the external power pack, I have seen one model 30 hp late 80's I think, that had a curved power pack under the fly wheel. Also around mid 90's OMC made a very basic but very tough commercial 25 hp. good luck on your search.

Re: Best era for 30-40 hp Johnsons

dkonrai said:

i have a 72 20hp, upgraded the carb to 25hp. overall pretty happy, almost too much for my 14footer. figure this, 25hp 82 pounds. thats about 6 more pounds than a 9/15 but almost twice the power. jmho.
dino

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Sorry to say, sir, but there is more to a 25, than just changing the carb. The 25 has a different exhaust set up and different pistons. They're the same cubic inch displacement, but converting a 20, to a 25, will take more than just changing the carbs.

Re: Best era for 30-40 hp Johnsons

1946Zephyr said:

Sorry to say, sir, but there is more to a 25, than just changing the carb. The 25 has a different exhaust set up and different pistons. They're the same cubic inch displacement, but converting a 20, to a 25, will take more than just changing the carbs.

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^this
i have a 1969 evinrude 25hp sportster. had it in the family since new. love this engine. if i remember correctly, they are a 18 hp but are equiped with high performence upgrades, power head, carb, pistons. i think the 18 weighed in at 80 lbs and the 25 only 1 pound more at 81 lbs. those 25's are screamers.

Re: Best era for 30-40 hp Johnsons

Carburetor, pistons, cylinder head, exhaust tuning, and a balanced crankshaft to handle it.

Re: Best era for 30-40 hp Johnsons

Thanks for the input. Sounds like a late 80's-early 90's OMC motor would work well. I'd really like the shifter in the front on the tiller handle too, but it's not a deal breaker. I have a little DIY fix for that. Is there any truth to the idea that new(er) motors, which measure hp at the prop rather than the powerhead, and are more powerful than their vintage counterparts. If so, by how much. Is a modern 25hp closer in power to a vintage 30hp? Thanks again, I'll keep you posted on what I can find.

Re: Best era for 30-40 hp Johnsons

Was wondering if you knew where to get the 25 to 35 conversion parts

Re: Best era for 30-40 hp Johnsons

54bobby said:

^this
i have a 1969 evinrude 25hp sportster. had it in the family since new. love this engine. if i remember correctly, they are a 18 hp but are equiped with high performence upgrades, power head, carb, pistons. i think the 18 weighed in at 80 lbs and the 25 only 1 pound more at 81 lbs. those 25's are screamers.

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oh no... i have been misinformed thanks for clearing that up. kind of like the 9.9/15 series carb swap?

Re: Best era for 30-40 hp Johnsons

I don't know a bunch about HP ratings but have been told that the older Mercury motors were rated at the prop while most others are rated at the P/H Don't know how well this holds true today. One other option for low priced power might be to check out the older 2 stroke Suzuki or Nissan motors I have worked on both and they seem to be well made, parts cost more and are harder to come by tho. Best of luck.

Re: Best era for 30-40 hp Johnsons

You must be clairvoyant kodibass, I was just looking at an 1980-something, 30hp Suzuki ion c-list yesterday. It's missing the carb and few other small bits, but it looks to be 90% complete and it's only $100+a tank of gas to get there and back. As I understand it, the lower hp (< 50hp) Zuki/Nissan/Merc/Yamaha are all essentially the same motors with different cosmetics, or am I wrong? I know folks LOVE old Yamaha 2-stokes (especially the red decal "Enduro" models), but they aren't easy to find, or cheap. However, the other brands seem to be more common and much less expensive. I'm really open to pretty much anything in the 30hp-40hp range, with reliability being the primary factor. Keep the ideas coming.

Re: Best era for 30-40 hp Johnsons

I THINK NISSAN & Tohatsu as well as some newer Merc's are all the same basic motors with different trimmings the suzuki I think they are kinda for the most part still just suzuki, I own 2 zukies a 40 & 60 hp models I do very much find them to be very reliable well made outboards.