'Rude/Johnson "weedless" lower units and props ?

[kyron4]

Hello, alittle bored and curious. On the Evinrude lightwin and Johnson seahorse 3hp with the "weedless" LU ,I had some questions.

1. Why did they switch from 3 blade props to 2 blade props ?
2. Is one better/faster than the other or more or less equal ?
3. Are the props interchangable, as the LU gears are the same aren't they ?
4. Anyone know the size and pitch of the 3 blade prop ?

-Thanks, again more bored and curious than anything.

 

[F_R]

Re: 'Rude/Johnson "weedless" lower units and props ?

Hello, alittle bored and curious. On the Evinrude lightwin and Johnson seahorse 3hp with the "weedless" LU ,I had some questions.

1. Why did they switch from 3 blade props to 2 blade props ?
2. Is one better/faster than the other or more or less equal ?
3. Are the props interchangable, as the LU gears are the same aren't they ?
4. Anyone know the size and pitch of the 3 blade prop ?

-Thanks, again more bored and curious than anything.

1. The 3 blade over-revved on some light boats
2. The two blade should be faster in some cases, although neither is exactly "fast".
3. Yes
4. 6-1/2 x 5-3/4 three blade, 6-1/8 x 6-1/4 two blade

 

[kyron4]

Re: 'Rude/Johnson "weedless" lower units and props ?

Thanks , interesting stuff

 

[MudLake]

Re: 'Rude/Johnson "weedless" lower units and props ?

I have a johnson 3 hp weedless with 2 blade prop and

a evinrude 4 hp with a 3 blade prop.

Both motors have the 20 degree facing down gearbox.

The 3 hp 2 blade is far superior as a weedles outboard as the weeds are basicaly screwed off the prop do to the twist design of the blades.

cheers

 

[Texasmark]

Re: 'Rude/Johnson "weedless" lower units and props ?

Don't know what the 2 blade looks like, but I have operated the 3 (laid back) blade type in thick coontail moss and lillypads. The ability of this little critter to snake along is incredible. Just wished they had made it in larger hp versions as once you get out of the stuff and head for home, it takes a long time to get there.

Mark

 

[1946Zephyr]

Re: 'Rude/Johnson "weedless" lower units and props ?

Yea, I have two of these critters myself. Intriguing design.

 

[arks]

Re: 'Rude/Johnson "weedless" lower units and props ?

Just curious: why did they have the 20 degree facing down gearbox?
Seems to me that feature would make them awfully inefficient.

 

[F_R]

Re: 'Rude/Johnson "weedless" lower units and props ?

Just curious: why did they have the 20 degree facing down gearbox?
Seems to me that feature would make them awfully inefficient.

You are correct, it is inefficient. But it is designed to be weedless, not fast. It is all part of the design to let it hop over obstructions, go through hayfields and almost anything else you can throw at it. BTW, if you look closely at the propeller, there is mighty little clearance between it and the gearcase. That is to cut off the weeds that it doesn't shed.

 

[Texasmark]

Re: 'Rude/Johnson "weedless" lower units and props ?

10-4 on the not efficient and not designed to be. I assume OMC (BMR or whatever) assumed the trolling motor took over the task of snaking through the crud. Well, as far as I'm concerned it didn't. Maybe sales as a % of total revenue weren't adequate to support the model.

Mark

 

[1946Zephyr]

Re: 'Rude/Johnson "weedless" lower units and props ?

I believe the design is at least 20 years in the making. I seem to recall that the old 3.3hp Evinrudes had it, pre-1950 and I believe enen the Zephyr did too.

 

[F_R]

Re: 'Rude/Johnson "weedless" lower units and props ?

I believe the design is at least 20 years in the making. I seem to recall that the old 3.3hp Evinrudes had it, pre-1950 and I believe enen the Zephyr did too.

Yep, a similar unit was on the 1941 Sportwin 3.3hp. Similar but not same as. I think the "modern" version came out in 1952. Older ones than '52 had centrifugal water pumps.

 

[1946Zephyr]

Re: 'Rude/Johnson "weedless" lower units and props ?

Yep, a similar unit was on the 1941 Sportwin 3.3hp. Similar but not same as. I think the "modern" version came out in 1952. Older ones than '52 had centrifugal water pumps.

Now, the latest I have seen so far, is on a 1970 4hp, I have sitting in my shed, which is just an upgraded version of the ealier 3hp Light Twins. So, my guess is, the weedless prop design went into the 70's, or later. I see a 4hp in my manual, going all through the 70's and even through 1988, but I'm not sure what year they did away with the weedless prop design.

 

[kyron4]

Re: 'Rude/Johnson "weedless" lower units and props ?

Just curious: why did they have the 20 degree facing down gearbox?
Seems to me that feature would make them awfully inefficient.

I saw an old ad for a johnson seahorse and it had 3 drawings showing it going thru weeds, "rideing" over a stump , and running up on a sand bar. Can't read the description though.Seems it was more a "keeps going and going..." design than fast and efficent. Here's a pic , kinda small.

 

[F_R]

Re: 'Rude/Johnson "weedless" lower units and props ?

Now, the latest I have seen so far, is on a 1970 4hp, I have sitting in my shed, which is just an upgraded version of the ealier 3hp Light Twins. So, my guess is, the weedless prop design went into the 70's, or later. I see a 4hp in my manual, going all through the 70's and even through 1988, but I'm not sure what year they did away with the weedless prop design.

From what I can figure out, 1982 was the last weedless.

 

[1946Zephyr]

Re: 'Rude/Johnson "weedless" lower units and props ?

From what I can figure out, 1982 was the last weedless.

So, there we have it. 41 years in the making. A Zephyr with the weedless prop, would be quite a find.