Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

[bob marco]

My 1975 Evinrude 4HP 2-stroke has died. Don't ask!

It was a 2 cylinder model but weighed only 36 pounds.

I'm planning to replace it with a new 4-stroke since no one seems to make portable 2-strokes anymore. But since the weight of all the 4HP 4-strokes is so much more than 36 pounds (Yamaha 48 lbs, Merc 57 lbs, Suzuki 55 lbs), I was thinking of going to a little smaller HP rating.

For example, Nissan 3.5HP is 43 lbs and Suzuki 2.5HP is 30 lbs.

I've read some say that 2-strokes are a little more powerful than same rated 4-stroke (particularly at lower RPMs). But perhaps this relates to new 2-stroke vs. new 4-stroke.

Bottom line: will a new 2.5HP or 3.5HP compare in power with my 33-year-old 4HP, or will I be forced to take on the extra weight to keep the same performance? I guess I'm hopeful that technology has increased a lot in 30+ years and I'll be able to get by with a smaller engine today.

Thanks!

 

[JB]

Re: Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

Howdy, and welcome to iboats.

There is no 4 stroke (and probably no non-OMC 2 stroke) that is comparable to the wonderful little JohnnyRudes, Bob. They are incomparable.

Fix the one you have or go find a good used one and send me the old one.

 

[jspringator]

Re: Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

Look on e-bay and see what used 2 strokes are comparable. Sometime in the 80's horsepower began to be rated at the prop, which means your 4 may actually be a 3 1/2. I have a lightweight single cylinder Tohatsu 3 1/2 which is VERY easy to start and runs well. I started it up yesterday. After sitting for 2 years, it started on the second pull. I did put in new gas. Not as smooth as an an OMC twin, but readily available on e-bay.

 

[bob marco]

Re: Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

Well, coming from a guy with over 32000 posts, I'll have to take your suggestion seriously. I'll post a repair related item in another forum.

I'm still insterested in 4-stroke engine comparisons, though.

 

[ondarvr]

Re: Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

How do you plan on using the motor? If all you want is something to get you from here to there occasionally, or as a back up motor, then most small motors will work OK. If want to use it a great deal for trolling, or as the main motor, then there is nothing currently being made that can compete with what you had.

The newer small motors are single cylinder models that tend to vibrate a great deal and are also loud, they can be irritating to use for more than just a short time. Plus they don?t seem to last as long, it appears price is more of a target than durability, they aren?t bad, just not as good.

 

[CATransplant]

Re: Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

I gather from another thread that you're using this on a side bracket mounted on a canoe. For that use, the very light weight of the Evinrude 4hp is ideal. Going to a heavier 4-stroke is going to impact your use quite a bit in that situation.

Were it me, I'd be scouting up another 4hp johnnyrude. There are tons of them out there, and they're all lightweight, reliable, quiet, and don't vibrate your arm off like the singles.

 

[marquette]

Re: Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

on craigs list $250 will buy you another mid seventies to early 80's Johnnyrude 4hp. what could you buy new that would be any better built 2 stroke or 4 stroke for twice that price. and you would have your old one for parts.

 

[bob marco]

Re: Replacing 1975 Evinrude 4HP 2-stroke. What 4-stroke is equivalent?

Thanks everyone for the replies. I don't think I can handle the diagnostic work myself, and I don't have anyone locally that is reasonably priced AND trustworthy.

I think I may look for a decent similar used replacement.