old 40 HP johnson

[corzy]

Hey guys, figured i'd start a new thread now that im ready to try and get this motor going...
its a johnson electric
the model number is RK-25D and the serial number is C379622
i think this makes it a 63 but not overly sure....

i have a question about wiring.
there is a wiring block with 6 wires going into it...2 black, 2 blue a pink and a purple (but there so old that the faded colors might be a lil bit different)
there is also 2 other smaller wires that are on there own blue and white (figured they were for the ignition?)
and obviously a big red and big black for the battery
any suggestions on how to hook it up to try and start the ol girl? i dont have an ignition, and my electric shifter only has a 3 wire block????
let me know what you think, i might just jump the starter to get it going (unless you think this is a bad idea)
thanks

 

[corzy]

Re: old 40 HP johnson

no takers? Tomorrow ill have the motor fastented to the boat, so ill be ready to try and start it, but not sure how i should hook things up..should i just leave it un wired and pull start it (ouch) how do i stop it if it does start?
pulled the carb off today, very clean, i was quite supprised, last boat motor i worked on had a carb per cyl...only one for both on this ol girl...kinda cool, but not so cool that you need to pop off the starter just to get it out.....
also looked like there was an empty spot on the port side of the motor for a starter...just wondering why there would be 2 spots to put a starter?

thanks

 

[tx1961whaler]

Re: old 40 HP johnson

The empty spot is for a belt drive generator.
You can easily jump start the motor and it will run.
Flip the choke closed to stop.

 

[kodibass]

Re: old 40 HP johnson

If you don't have one get yourself a manual for it, save you some head scratch'n.. good motor. you can rig up a start switch via a solenoid , I used a newer (8o's) 35 hp model stop switch for the start button. I just choke mine to kill it. good luck..

 

[corzy]

Re: old 40 HP johnson

ok great tips
so i mounted the engine today and got it centered on the transom...the engine mount bracket is pretty level, but the outdrive is quite slanted to the port side...should i jack up the SB side of the mount bracket then bolt the bottom so the outdrive sits level, or should i just bolt it as is...im sure it wound't be too bad, might drive in circles a bit hahaha
thanks
corzy

 

[corzy]

Re: old 40 HP johnson

oh and i see there's no intake on the side of the OD so i cant use the muffs....how deep does it need to be, is the intake under the anti cavitation fin, or is it under the the outdrive attached to the motor above the extention?
thanks guys

 

[bullcity101]

Re: old 40 HP johnson

I believe it is above the cavatation plate on those old girls. How long has it been since she has run? What are compression #'s like? Might want to look at the lower unit gear oil and water impeller. have a friend jump the starter and see if you have spark. Worth checking the simple stuff before you go through all the trouble of getting her centered and all that.

 

[corzy]

Re: old 40 HP johnson

yes im going to get it to run before i bolt it down...looks like the one side of the OB is rubbing on the mount, the other side has half inch...no good, makes it super hard to trailer the engine up, dont remember it doing this yesterday before i tightened the clamps right down???
but my question now is how to jump the starter, its been years since ive done this and none of the main cables are hooked up as you can see from the pics...so if i remember, the main battery cable hooks right to the starter motor on the front where the bolt is right? where does the other cable go? i dont want to fry anything...so here are some pics, please lil help?
also that is my control...does it match? i have my doubts since the wire blocks are different...
thanks guys

 

[corzy]

Re: old 40 HP johnson

oops, wrong pics...
here try these

 

[corzy]

Re: old 40 HP johnson

on the first pic is a close up of a busted lever and faintly there is an arrow that says start and points backwards....what is that lever for?
the second is just the wireing as you can see only 3 wires...looks like the gear cable will hook up ok
the third is the port side, i think thats the starter cylinoid right? you can see the 2 cables popping up on the left, blue and white i beleive, do they go to the cylinoid?
5th is the starter motor, does the main batt cable hook right to the bolt facing the front of the boat, near the bottom? im guessing to bump start it you just touch ground?
and the last pic is the cables coming from the motor, as you can see the block is much bigger than the one on the control....
any info on this baby would be awesome...thanks

 

[corzy]

Re: old 40 HP johnson

ok so i found this wireing diagram, but i am no electrician so its a bit over my head. i see the main positive cable comes in to the starter cylinoid, and then to the bolt on the bottom front of the starter motor. but im not sure which is the in and which is the out on the starter cylinoid....also im not sure where the main ground is to be connected either...also where on the starter motor is it to be grounded?
any help?
thanks

 

[tx1961whaler]

Re: old 40 HP johnson

The big red cable goes from the battery + terminal to the big terminal on the solenoid. The power cable to the stud on the starter goes to the other big terminal on the solenoid.
The big black cable goes from the battery - terminal to the engine block.
One of the small terminals on the starter solenoid get 12 volts from the starter switch.
The other terminal gets grounded, usually through a neutral safety switch

 

[corzy]

Re: old 40 HP johnson

ok, ill take a closer look at it tomorrow, but i guess i just cant find the "big" terminal on the block for the ground, or the "big" terminal on the cylinoid...can you point it out in any of the above pics???
thanks though that will help a ton

 

[corzy]

Re: old 40 HP johnson

ok so after looking at the pics with a guy from work, looks like theres no cylinoid...should have been obvious since why would the battery cables not be connect to anything??? sucks.
anyways, looks like there only 35 bucks on this site so ill order one up.
but in the meanwhile, i should be able to still jump the starter motor right? positive to the nut on the bottom, and negative to the frame? i did this today but nothing at all happened...the starter isn't ceased because i can spin it and it goes up the the Flywheel...maybe i grounded it on a bad spot or something, ill try tomorrow again, but even if the starter was no good, it should at least spark, no? the battery is ok....

 

[tx1961whaler]

Re: old 40 HP johnson

THe starter should work if jump started like you described.

 

[corzy]

Re: old 40 HP johnson

SHE'SSS ALIVE!!!!
wow got her started today, couldn't beleive it hahah
took the starter right out (again) pulled it apart and she was pretty corroded (explains no contact when i tried to jump it)
put it back in, only stripped one bolt (frig sakes) jumped it and it started right up, must be the cleaned carb with new gas it didn't crank over for 5 seconds and it started!!

so my questions now are
1 - how deep does the outdrive need to be in water? no water from the water pump, but my garbage can might not have been up high enough. heres a pick of the engine again, does the water line need to be just over the anti cavitation plate, or all the way up over the extention?


2 - i have a solenoid off of a 90 hp merc from a jett boat i used to have, will it work on this motor? it looks a bit different, but has 2 big posts and 2 small ones.

3 - the bolt i stripped was one of the starter bracket to the block bolt, it stripped the threads in the block...any suggestions on what to do to fix this? doesn't seem too crutial since its still solidly in there, but im worried that the ground might not be as strong.

thanks guys....just real glad this baby started

 

[corzy]

Re: old 40 HP johnson

any takers? would really like to get going on this baby, could be doing some wireing soon but need a little guidance
thanks again

 

[tx1961whaler]

Re: old 40 HP johnson

1. Way deep. It need to be almost up to the exhaust hole in the midsection. I use a big metal trash can.
2. The Merc solenoid would probably work. An auto one works, but burns out any safety switches attached to it, since the auto solenoid grounds through the solenoid case. A marine one doesn't.
3. Helicoil

 

[corzy]

Re: old 40 HP johnson

great, thanks for the response whaler! and good news too, ill have to get a big can, or barrow a truck and go to the ramp and see if she is working...
ya i figured it would work, and yes the solenoid is insulated from the block so should be ok i would think...
ill have to look into this helicoil deal, thanks
ill let you know how i make out...will be working on wiring next im sure : )

 

[tx1961whaler]

Re: old 40 HP johnson

I just rip out all of the old crap and rewire directly. I have all of the wire and terminals and crimpers and heat shrink available, so it only takes me a couple of hours to have it all done. The minimum you need is:
The battery cables
The wire from the start switch to the solenoid
The 2 kill wires from under the magneto
Electric shift wires if required.
Very good to have stuff: Neutral Safety switch, cylinder cut-out switch
Optional: Generator stuff. Electric choke switch.