New to me Johnson Outboards

[AgTires4295]

Okay, I'll be trying this again. Before, I had written out this very detailed post and the computer crashed.

I recently purchased two Johnson outboards (30hp and 35hp). They had both been purchased about 10 years ago and were allegedly put away in storage in running condition. While I know both a nearly identical, I want to use the 35 for my boat as it not only has more power but has an electric start. Brief questions:

-Are these outboards generating power to charge my boat batteries?

-What are preventative maintenance procedures for these outboards aside from changing the lower gear oil and installing a new water pump?

-Why does the 30 have wires running from the block to the handle?

-I've enclosed the model/serial numbers for both units. I have not been able to locate much information in decoding the numbers but can tell that the 30 is obviously a long-shaft from 1986 and that the 35 is a short-shaft from 1981. Anything else that I am able to get from those numbers?

-I see that the 35 has a missing fuel pump. Is it that the 35 has two pumps vs the 30 just having one? More fuel does mean more power, so I'd think this is the case.

I'm sure I'll be generating more questions as time rolls on. Any input is greatly appreciated.

 

[Bosunsmate]

35hp should charge your battery since it has elecgtric start but you never know what people have done to a motor.
I cant see a rectifier on it which changes ac to dc for the battery, might just be the photo angles.
The 35 will just have one fuel pump too. Even bigger motors such as 100hp have only one pump.

You should definitely change the water pump impellor

 

[Bosunsmate]

grease it too, theres a few grease nipples around.
If you are up for it id also suggest putting in a new head gasket and cearing out the water channels when you do.
And also checking the thermostat operates

 

[AgTires4295]

Great, thanks for the replies! In photo 7 (white engine block with the little black box that reads "CD2"), is that the rectifier? I didn't know what it was but have been doing some research on here since I posted.

I'll likely not put in a new head gasket (truthfully) unless there are any issues but what would indicate that it would need replaced other than dry-rot? I'm not too familiar so I'll ask: Does the water from the lower unit flow up and through the head like coolant in a car and then out with the exhaust? I'm pretty good at taking stuff apart and not putting it all back 100% so a head gasket may be over my head.

I had no clue these engines were complicated enough to have a thermostat.

 

[Bosunsmate]

cd2 Is the power pack, the square thing to the left of it along the motor that is a bit grey and a black back is the starter solenoid.... so i cant see the rectifier regulator yet, maybe the other side in front of the fuel pump?

 

[Bosunsmate]

I'll likely not put in a new head gasket (truthfully) unless there are any issues but what would indicate that it would need replaced other than dry-rot?.

Its a maintenance thing but doesnt need to be done often at all unless its being used in saltwater, the channels can salt crust build up in salties quite quickly even if flushed out.. If the compressions ok and its not a saltie then its not something to dwell to much on

 

[Bosunsmate]

I'm not too familiar so I'll ask: Does the water from the lower unit flow up and through the head like coolant in a car and then out with the exhaust? I'm pretty good at taking stuff apart and not putting it all back 100% so a head gasket may be over my head.

Yep thats how it works, most motors have a little outlet on the underside of the engine cover so when you are using the motor you can look behind and see a stream of water coming out which indicates the pump is working, its called a tell tale. Its on the starboard side, i can see it on the 30hp i think but not on the 35hp.

 

[Bosunsmate]

I had no clue these engines were complicated enough to have a thermostat.

The thermostat can be seen on that 35 straight above the top sparkplug.
Some people think they over complicate matters and remove them but then the engine takes a long time to warm up so you can end up cold seizing it and it will also run too cold and end up carboning up leading to seizing too so they should always be kept in mind.
If they seize up and dont open up the engine can overheat.

Looks like on that motor you would need to take off all those little bolts on the back cover, and then replace the gasket there. The gasket would be relatively cheap $5. The bigger bolts are the headgasket which you dont need to undo.
If you dont want to take that on yet just run it in a barrel or in the water for a while, if the top of the motor gets too hot to hold your hand on it for a few seconds at least then its overheating. They shouldnt get above 70celcius, so if you touch it and you get scolded then you will need to look further into it

 

[AgTires4295]

Great replies. Thanks! If this thread can be kept alive with more input, thatd be wonderful.

My ultimate goal is to mount the 35 on the boat, utilizing it with controls and steering from a wheel. I have a set of controls already but need to figure out the steering part (I'm a newbie at building a boat). Hoping to do more research and find what components are needed outside of a wheel rigged to a cable.

 

[racerone]

Both these motors produce the same power.---One is 30 hp at the prop and one is 35 at the crankshaft.

 

[AgTires4295]

Both these motors produce the same power.---One is 30 hp at the prop and one is 35 at the crankshaft.

Not to seem too far out in left field, but you threw me off with that one. If they're producing the same power, why is it that Johnson didn't have a standard to measure and label each engine the same? If they both produce 35hp, why did they do this?

 

[F_R]

At some time in history, it was decreed that all outboards had to be measured at the prop, in order to make it a level playing field. There is some energy loss through friction and changing directions in the lower unit, thus the difference.

 

[F_R]

I get real confused reading the description and model numbers 30ELCD left the factory as a 1986 30hp Electric start. 35RCI left the factory as a 1981 35hp Rewind start (not electric). So, the best I can conclude is that those motors have both been messed with. Does the 35 charge the battery?? Dang if I know considering the unknown history. You will have to inspect it to see what's there and what isn't. Looks to me like there is a bunch missing.

 

[AgTires4295]

At some time in history, it was decreed that all outboards had to be measured at the prop, in order to make it a level playing field. There is some energy loss through friction and changing directions in the lower unit, thus the difference.

Wow a whole 5hp though? So these engines are literally the same with the exceptions that they are different shaft lengths and one has an electric starter? If that's true, that's great (I guess better than having a slightly smaller engine), but the long shaft 30hp doesn't look nearly as complicated under the hood as the 35. If anything, since the 35 is 5 years older than the 30, I'd think it would have less technology vs the other way around as it is currently.

 

[racerone]

Yes they are the same internally and all.---Just different decals between the years.--The electric start is easy to swap between the 2 motor too !!!!

 

[AgTires4295]

Yes they are the same internally and all.---Just different decals between the years.--The electric start is easy to swap between the 2 motor too !!!!

Wow that's exciting! I was thinking I'd sell the 30 but if they're literally identical, I think I'll just hang on to it! So the carbs are the same and all? I'm just blown away since the 35 looks like it has so much more going on mechanically and electrically under the hood.

 

[F_R]

There were a very few outboards made through the years rated at peculiar horsepowers, I guess the 28hp, 33hp, and 48hp would be prime examples and they were all sold as price leader motors. Settle for a couple of horses less and save some dollars, and stay away from the dealer down the street. But for the most part they were rated rounded off to 5hp increments. The rest of the story is that individual motors may vary a couple of horses simply because of allowable tolerances.