1966 33hp johnson, electric start, No generator, wiring diagram needed

MadTom

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iboat 009.jpgiboat 011.jpgiboat 014.jpgiboat 016.jpgiboat 017.jpgPlease help

I've acquired this engine and most of the wires have been cut. It's also connected to a merc control box rather than a johnson, which apparently makes the neutral safety switch an issue as well for me to figure out. Pics should be attached here,, if you can't see them lemme know plz. I would greatly appreciate some help, in the form of wiring for dummies. The previous owner had to touch two black wires to cut the motor, so this was a probably never wired correctly for him either.
 

lindy46

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Pic #1 - that is the cut-out switch. Should have two wires to the center post: one black coming from under the flywheel/mag plate and the other going on to an "M" terminal of the ignition switch. There should be another black wire coming from under the flywheel/mag plate going directly to the other "M" terminal of the ignition switch. The side terminal has the wire in place going to the neutral safety switch, but should have a second wire going to one of the small terminals on the starter solenoid.

Pic#3 - the fuel inlet hose is missing.

Pics #4 & 5 - can't really see the markings on the back of the switch. There should be a "B" terminal with a power wire coming from the battery, probably the red wire, and a jumper supplying 12 volts directly to the choke solenoid supplying power when you hit the choke button. Looks like they are correctly in place. Then, as mentioned, two "M" terminals with black kill wires. Not sure if that green wire may be one of the kill wires. The last terminal would be an "S" terminal for start. A white wire from the other small starter solenoid terminal would connect there. When the keyswitch is turned to "start position, it closes the 12 volt circuit and supplies power to the starter solenoid to activate the starter.
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Thanks Lindy46. My igniton switch only has 4 poles. "IG", "ST", "B" and "ACC".. Safe to assume that's not original. I've attached a wiring diagram that I've drawn up with some of the missing / stray wires etc. I've also attached two more pics.

I'm not clear on what you mean by "The side terminal has the wire in place going to the neutral safety switch, but should have a second wire going to one of the small terminals on the starter solenoid." Where is that in one of my pics?

As far as my igniton goes, there are no "M" terminals. Although there is a "IG" with a black cable connected to it, and I don't know where it goes. I think I wrote this before - the previous owner had to stop the engine by touching "two black wires together" - I'm now assuming that another black wire was attached to the centre post on the cut-out switch as you mentioned and he would kill the engine touching these two wires together - do you have a solution for this with my current equipment (or should I source a new ignition switch with two "M" connectors.

On my "B" terminal from the ignition, there are two red wires One goes to one terminal on the choke button, the other is not connected From your response, this should go directly to the battery - should I fuse this? - I do have two stray fuse assemblies.
The "ST" on my ignition switch is for start, it appears to be green (for some reason the white wire with the lug is not connected)- So I should attach the green wire from 'ST" to the only available terminal on the solenoid.
DIAGRAM MISTAKE: Sorry, I've shown the + terminal of the battery connected directly to the starter - this is wrong,,, the starter is connected to the other pole of the solenoid
johnsonn 1966 33hp wiring scan.jpgjohnson 4 wires.jpgjohnsonn 1966 33hp stray wire.jpg
 

kfa4303

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MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

thanks, it's starting to piece together.. please look at the attached photo of my solenoid(the way I received it)solenoid.jpg,, i understand the connections on the two larger poles are correct (one to positive battery, the other side to positive on starter) . On my pic, the negative ground from battery is connected to one of the small terminals.... is this wrong ? the diagrams I see, the small terminal nearest the +starter side of the solenoid goes to the cut-off switch, the other small terminal on the battery+ side attaches to one of the terminals on the key ignition switch
UPDATE : if my assumption is right, this is wired wrong , the intention was to bypass the safety switch - which creates new questions - how does the safety switch work, how is it activated and why would it be bypassed? ( this boat came with a geri-rigged merc controller for gear and throttle, so there is no neutral safety switch mechanism available)
UPDATE: I know see that the neutral safety swich has nothing to do with the gear/throttle control box,, I see that the switch is below the flywheel and as the gear shift physically moves it either opens or closes that safety switch. My safety switch has another lead on it which is not attached,,, should it be attached back to something (one lead is to come from the cut-off switch and the other end is not attached) - looks like a flat connector. I need to have this function working , for safety reasons.
 

newhamburgboating

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Hi MadTom, i recently went through this with my 69 40HP Johnson, take a look at the diagram i altered. I simplified it from another i was given that had a generator.
Wiring1969-40hpWithoutGeneratorKit.jpg

like i said, it's not the exact motor, but your pictures and description are very familiar to my experience.
 

lindy46

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

thanks, it's starting to piece together.. please look at the attached photo of my solenoid(the way I received it)View attachment 197891,, i understand the connections on the two larger poles are correct (one to positive battery, the other side to positive on starter) . On my pic, the negative ground from battery is connected to one of the small terminals.... is this wrong ? the diagrams I see, the small terminal nearest the +starter side of the solenoid goes to the cut-off switch, the other small terminal on the battery+ side attaches to one of the terminals on the key ignition switch
UPDATE : if my assumption is right, this is wired wrong , the intention was to bypass the safety switch - which creates new questions - how does the safety switch work, how is it activated and why would it be bypassed? ( this boat came with a geri-rigged merc controller for gear and throttle, so there is no neutral safety switch mechanism available)
UPDATE: I know see that the neutral safety swich has nothing to do with the gear/throttle control box,, I see that the switch is below the flywheel and as the gear shift physically moves it either opens or closes that safety switch. My safety switch has another lead on it which is not attached,,, should it be attached back to something (one lead is to come from the cut-off switch and the other end is not attached) - looks like a flat connector. I need to have this function working , for safety reasons.
The large red wire on the large solenoid terminal should connect to the battery. There should also be a 12awg wire coming off that post going to the "B" ignition post (if that is indeed the "battery" post). Fuse it if you wish. That is probably the loose red wire you see attached along with the wire going to the choke button. The negative ground from the battery should be a 4awg black wire and it should NOT be connected to the solenoid. It should ground to the engine, usually connecting to one of the starter bracket bolts. If the "ST" terminal on your ignition switch is indeed the start circuit, then that green wire should go back to the small solenoid terminal next to the large battery solenoid terminal. Check to make sure the "IGN" terminal is not the start circuit. There should be a ground wire connected to the other small solenoid terminal which goes back to the side terminal of the cut-out switch. When the motor is in neutral, that closes the neutral safety switch which grounds starter solenoid allowing current to flow from the battery to the starter motor. The neutral safety switch should only have the one lead going to the side terminal of the cut-out switch (that's how it shows in your pic). "ACC" is usually an accessory terminal. But there should be two "M" terminals (magneto) which are for the kill circuit. When the key is turned to the "off" position, it closes that circuit and grounds out the points. You may need to use a multimeter on that ignition switch and find out which terminals are for the various functions. You don't want to supply 12 volts to the kill circuit as it will fry your coils. Refer to the schematics above. You may want to try and find a correct ignition switch.
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Thanks everyone for the info.

From this I think I can get it all wired up! I have a few more questions:
1) In my johnson manual, it shows the other lead from the neutral safety switch going to ground. In both your response and newhamburgboating I'm directed not to ground the other lead,,, why is this? (or is it grounded by virtue of being connected to the frame?)
2) is it difficult to obtain a comparable ignition switch so I don't have to use this one ?
3) since my ignition switch does not have the two "M" connections, can I wire the two wires that are supposed to go there to another on/off switch, essentially closing the circuit to ground out the points
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Thanks everyone for the info.

From this I think I can get it all wired up! I have a few more questions:
1) In my johnson manual, it shows the other lead from the neutral safety switch going to ground. In both your response and newhamburgboating I'm directed not to ground the other lead,,, why is this? (or is it grounded by virtue of being connected to the frame?)
2) is it difficult to obtain a comparable ignition switch so I don't have to use this one ?
3) since my ignition switch does not have the two "M" connections, can I wire the two wires that are supposed to go there to another on/off switch, essentially closing the circuit to ground out the points

IGNITION question: plz correct me if I'm wrong: if we disregard a switch with ACC,, the role of the igniton switch is to close the circuit between two connectors ("M") in the off position, and when it's in the momentary "ON" position, it closes the circuit allowing voltage to flow to the solenoid, as long as the safety switch detects it's in neutral and it opens the "M" circuit to stop the flow there. SO the electric choke could be connected to the ACC on my switch or directly to positive power terminal on the battery(since it has its own switch). How do I test the ignition switch to find out what terminals or open or closed in the different positions without actually wiring it up to everything. I already see that positive power is connected directly to the switch, but since I have no ground connected , do I simply ground the metal casing of the ignition switch?
 

newhamburgboating

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Any non painted part of the power head can be used as a ground, just use common sense :)

I bought a new ignition switch for about 12$ at my local marine store. Universal one works fine, mine has 5 posts, 2 M, 1 B, 1 S, 1 C.

Yes you can, the entire idea is when those two connect it will ground the ignition system and shut off the engine. Older motors didn't even have these, you just throttle down and it would stall.

The s connection on the ignition switch goes to the closest small post to the battery post on the solenoid. This is basically an on/off signal to Engage the starter.
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Thanks newhamburgboating. Much appreciated. The reason I asked about grounding the neutral safety switch was in response to Lindy46 comment "The neutral safety switch should only have the one lead going to the side terminal of the cut-out switch" - the manual indicates the other lead should go to ground.
BTW I did manage to find a Johnson manual which includes the wiring diagram for this motor online, I've attached it (just the diagram) here in case someone else can use it. It appears this 33hp was always manufactured with a generator, which has been removed from this particular motor - this made the drawing a bit more confusing.33hp johnson wiring from manual.jpg
 

lindy46

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Most of the neutral safety switches I've seen ground thru the mounting bracket. Does yours have another wire coming from it? If so, that may need to be grounded to the powerhead. Test with an ohmmeter to see if there is continuity between the powerhead and wire which attaches to the cut-out switch with the shift lever in neutral. If yes, you're good to go.
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

I'll test that out tomorrow, but I think the body of that switch is plastic so it doesn't appear to be grounded in that manner, and there is a crimped terminal / connection on the opposite side of the switch which the manual shows to ground to powerhead...... was also wondering if this switch is actually a Neutral Safety switch or a Low Speed Safety Switch on these 33hp motors?
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Thanks everyone - got it all wired up and started in a barrel!,,,I am posting this pic in another thread, but since you're here, can anybody identify what make model and year this boat is - there is no serial number or hull plaque.sidewinder-1st coat.jpg
 

newhamburgboating

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Hey MadTom,

Glad to hear! I just got mine going on Friday night, feels great. Will be taking it for a spin today if the rain holds off.
 

kfa4303

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Glad you got her running Tom! As for the hull, I'm not sure. Hull ID tags weren't required until the mid 70's so there's no telling what you may have. I would look all over the transom for a riveted tag, or inscription that may have some info. The good news is that the hull looks to be in good shape and the old 33hp will push it along with ease. I hope you're ready to hold on tight! These links may come in handy too.

Columns - Obsolete Outboards
Columns - Obsolete Outboards
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Hi

can anyone offer some advice on the top speed performance. I just can't seem to get enough power to plane the boat - doesn't seem that the motor is delivering full power. With the motor running in neutral, I can remove either the top or bottom spark plug cable and the motor will still run, i think that test verifies that I have spark. I tried to adjust the high speed rich/lean mix - the motor did respond and I've it set based on what the max speed attained was. Seems to burn up a lot of gas. Is there away or need to disconnect the vacuum cut-off - could it be the engine is dropping it down to one cylinder when in gear? I did not clean the carbs. I'm reading up on Seafoam, and was thinking of using this product or another,,,, any comments on that would be greatly appreciated too!
 

nwcove

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

visually check to make sure the choke plate is opened all the way , and properly clean and rekit the carb.....seafoam or other products wont magically clean a carb. jmo
 

MadTom

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

thanks nwcove .... I read the manual on how to set the low and high speed settings, as I suspected they weren't calibrated correctly. This totally improved the top speed. Although on my last run, (i was running low on fuel) the speed did increase , then had big surge in power, spuderred a couple of times and then stalled. I was able to restart it and just took it slow back to the dock... Is the spuddering likey because of crap in the carb?
 

lindy46

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Re: 1966 33hp johnson, electric start, No generator, wiring diagram needed

Yup, clean/rebuild the carb and replace the fuel lines if they are old. Old crud in the lines would just gunk up your newly cleaned/rebuilt carb.
 
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