Trying to identify 2000 Johnson/Suzuki 50 HP (J50PLSIB)

[garrettbirkhoff]

Hey all, I am tearing my hair out trying to get parts and a manual for the outboard we have. It is a Johnson 50 HP four-stroke, supposedly made September 2000. The model number on the plate is J50PLSIB -- but I see this referred to occasionally as a 2-stroke, but it takes straight gas and has an external oil tank, and I also think the motor may have been made by Suzuki. I'm trying to find a new rectifier for it, but all the ones for related boats (Johnson or Suzuki) are different (they are hexagonal; this is rectangular--photo attached). It might have been made for either the US or Canadian market originally. Not being able to find an authoritative parts listing is driving me crazy. Any ideas?

 

[Mc Tool]

Dude ... Thats definitely a 2 stroke motor . The external tank should be filled with 2 stroke oil and it is then drawn into the motor by a pump and metered and then the correct amount of that oil is mixed with the fuel automatically......so yes you would put straight gas in the tank .
As for the reg/rect ....doesnt matter what shape it is as long as its able to handle the current .

Just an example .....as long as it physically fits ( yes it says 4 stroke but it doesnt make a difference .....they are like spark plugs in that they use the same one for lots of motors ) and ,yes it Chinese but the one you buy from Johnson for 3 times the price will be too ( Johnson dont make reg/rects ....the buy them in ). Have a look on ebay ,Aliexpress , Amazon ....there are heaps .
Here is the Aliexpress reg/rect I fitted to my Tohatsu , cost me NZ$18 . I had to make a long bolt with a couple of extra washers to fit it , ....bonus ...the hour meter slips nicely over the fin so I didnt have to make a bracket for that.

 

[garrettbirkhoff]

Thanks so much for this! I just inherited this boat with no manuals or anything. I actually didn't know they did separate oil back then. Are there any sources where I could learn about how to test the charging system on this one?

 

[Mc Tool]

Put your volt meter on the battery , motor off it should show about 12v , then start the motor and hold it at a fast idle and you should see that voltage at about 13.5 to 14v . If there is no rise give it a quick rev and it should go up . This shows the charging system is working . If there is no rise its not .......we go from there
When you run the motor you must have water going to it , either with the ear muffs or the motor in a tub of water , or actually in the lake river whatev

 

[garrettbirkhoff]

I don't see any rise, or any change as the motor shifts from idle to ~2500 RPMs. So now could the problem be in the rectifier, or in the stator? Help videos I see online for testing rectifiers look very different from my set up.

 

[Crosbyman]

check yellows for AC volts from stator if ok .....bad rectifier or connection back to the battery B+ check all wires for corrosion

check B+ on RED out of rectifier to see it rises !! as it should like the battery test above

reconfirm engine mdl# !!!

 

[racerone]

The---SI---makes it a 2001 model.-----Color is correct for that year I think.

 

[Crosbyman]

check amazon #OB 12vdc volt /reg cheap just mount up somewhere

 

[garrettbirkhoff]

Got it! Thanks. The rectifier was faulty. Good voltage coming from the stator, but current flowing both ways across one of the diodes in the rectifier. I'll see if I can swap it out. And that it is a 2001 model, despite being made in 2000, helps clarify.