New to Johnson 15hp

[Sailpower]

I've just got a '78 15hp johnson seahorse to work on - looks like it had been looked after till it was stored a few years ago.

Missing the idle adj on the side, missing an ac lighting plug next to it, and an air box/silencer.

First question is can anyone point me to a resource that tells me what is different about the 15BAL78B ? I've seen it referred to as a 'recreational' model. I intend to use it in fresh and sea water. I see a lot of other 15hp model designations, - don't know what the implications are but I need a manual and don't see any genuine ones for a BAL model? I can see manuals for a 15R78 and a 15E78 so would another '78 15hp manual be OK?

If I have to go aftermarket, is Seloc or Clymer preferred? I've enjoyed browsing www.sschapterpsa.com but would like some tech exploded views and specs as well from a manual.

Theres no spark yet, comp was 75psi on both with the plugs out pulled over by hand (not electric start) which seemed low - hope its sticky rings. Going to try ignition system first, but can the powerpack and or coils be upgraded to later CDI ones or should I stick with the correct model year fitments? (Think its the CD2 PP fitted)

Scanning for spares in the UK but seems as well to get them from the US where availability seems very good.

Is there anything you guys would reccomend to do first to bring this motor back to life?

Head gasket/thermostat/fuel pump overhaul/carb clean and overhaul/new plugs/ gearbox oil and impellor seems like an expensive way to begin but probably eliminates further issues later?

 

[TN-25]

Re: New to Johnson 15hp

...Head gasket/thermostat/fuel pump overhaul/carb clean and overhaul/new plugs/ gearbox oil and impellor seems like an expensive way to begin but probably eliminates further issues later?

If you want to have reliability on the water I would recommend all of the above. It underscores the importance of making sure the cylinder pressures are relatively close to each other and to judge the relative soundness to acertain the condition of the motor BEFORE you dump money into it. The compression being even is almost more important than the actual figure (to a point)...


I am not familiar with the U.K. offerings so I can't really comment with any authority. I will say that the 9.9 / 15 dumped the breaker point ignition and went with CDI ignition for 1977 in North America.

An AC plug cover? That is a new one on me, but where I am from (Canada) the 20 horse was offered from 1975-on with an AC plug for running powertools. In Canada we also got a 15-horse back in the mid to late 1960s that looked much different than the 20 horse but was really very similar. The cowling literally was the old Gale 15. The powerhead was the old 19.94 c.i. powerhead that preceeded the 22.09 c.i. (18-20-25) . It was a regional thing. See the attached picture for a glimpse of the oddball Canadian 15 Johnson from 1967 beside a 20.


So you see why I hesitate to be more specific. Your motor I'm guessing was made in Brussels and sounds a little different from the 15 that we are familiar with in North America. Do you happen to have any pictures of the motor with the cowl on and / or off?

 

[raczekp1]

Re: New to Johnson 15hp

Hi U.K
powerpack to your motor will fit from each motor from 4-40hp made in 1980-1990.just should be 2 cylinder unit.
in my 9.9 83' i instaled powerpack from 4.5 model and its ok.my friend got powerpack from 8hp and its also ok.
on ebay.uk there is plenty new parts to 9.9/15 hp so get new head gasket, termostat and water pamp impeler new sparkplugs.
here is many good guys to help you with problems.
carb-the best is to put apart and sink in cilit bang for 1 hour , after, just wash in pure fuel.
while head gasket change i recomend to flaten the head surface
http://www.youtube.com/watch?v=MkL2HIGRcaU

 

[Sailpower]

Re: New to Johnson 15hp



Thanks for the advice all, here are some photos - incl, the AC sticker and now empty AC plug aperture.interested if this BAL model is the same as a US model so I can get a '78 service manual to look after her. Wondering what the differences wth a 15RL or 15EL model might be as i can see '78 manuals for these on ebay.

Is the 75psi on both cyclinders an OK figure?

Thanks

 

[all duck'd up]

Re: New to Johnson 15hp

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Thanks for the advice all, here are some photos - incl, the AC sticker and now empty AC plug aperture.interested if this BAL model is the same as a US model so I can get a '78 service manual to look after her. Wondering what the differences wth a 15RL or 15EL model might be as i can see '78 manuals for these on ebay.

Is the 75psi on both cyclinders an OK figure?

Thanks

dont hold me to this but i think the RL was a rope start and the EL was a electric start

and 75 psi is kind of low

 

[raczekp1]

Re: New to Johnson 15hp

i got this kind of motor but 79'-looks the same,
but after looks like: http://www.youtube.com/watch?v=IrTwT9j7Om4
http://www.youtube.com/watch?v=GaOWC-Y9SkE&feature=related

 

[Sailpower]

Re: New to Johnson 15hp

dont hold me to this but i think the RL was a rope start and the EL was a electric start

and 75 psi is kind of low

Hey thanks, just looked on Maxrules.com and found a code chart - must have missed it before. It says R = rope start with tiller steer, E= electric start with remote steer and my BA code is for the AC power - I presume an aditional coil under the flywheel.
From that I guess the 15R78 manual would do just fine.

Regarding the comp at 75 - reading other posts its good if it's over 100? Could my low figure be just because its cold and hasn't been run in years? I'm wondering if its worth having the pistons out and a full tear down to be safe?

 

[Sailpower]

Re: New to Johnson 15hp

RACZEKP1 - Thanks for those video links - nice looking restoration it sounds really cool.

I checked out some other 15hp test runs in barrels and a few 15hp motors sounded very rought and full of rattles - bag of spanners as we say!

 

[James R]

Re: New to Johnson 15hp

Low comps could be that the rings are gummed up. There are several products to cure that. I prefer to tip the motor onto its transom mount and shoot the lube through the plug holes and leave it to soak. rotate the motor a little and let it soak some more.
I think your comps will come up.
Ex Limey here.

 

[Sailpower]

Re: New to Johnson 15hp

Hi - is there such a thing as an ex limey? lol

Anyway thanks for the tip. I got a can of combustion chamber cleaner by Quicksilver for another engine think its called sea foam in the states/Canada, but the motor needs to be running to use it. Do you think Meths would do it, or 2 stroke oil, or better use a proper product?

 

[boobie]

Re: New to Johnson 15hp

Have you tried another compression gauge as they will vary in readings ?

 

[ondarvr]

Re: New to Johnson 15hp

75 PSI is low, but there can be several reasons for a false low reading.

Not all pressure gauges read the same and it may read different if you use a screw in type or the rubber one that you just hold in place.

Pulling the rope by hand can give you a lower reading than an electric starter spinning it.

If it's been sitting and is dry, the reading will be lower.

Even with a low reading they sometimes run well, especially if the cylinders are even in PSI.

 

[jmendoza]

Re: New to Johnson 15hp

Get it running first, don't sweat the compression, as it has enough to start, and besides, they are both quite close, which is good. Some advice on power packs: never, ever, never pull the engine through with the plug wires dissconnected, there must be a complete path for the spark to jump to ground(earth for you limeys). Without that ground, the high voltage (10-30KV) collapses back into the system, and the solid state switching transistors, SCRs and FETs cannot handle more than 400 volts max, so it fries them. Often, it only partially damages them, but them they become increasingly intermittant until the finally fail altogether. In my opinion, points are better because you will never have this erratic, and expensive problem, but that's just my opinion. The AC outlet is for a charge coil under the flywheel, and on our engines here in the USA, it went to a rectifier than converted it from AC to DC for charging a battery, and DC running lights (12Volt). In addition, another optin was an electric starter, and then the engine came with the charge coil and rectifier as well to charge the starting battery.

Make sure the kill switch wires are properly connected, as I see the switch is missing. If this is not right, it will have no spark. If that is fine, and still no spark, you are in for a new power pack(don't buy used ones).

Once you have the engine running, you can check the water pump, and if it pumps water, go ahead and warm up the engine for 20 minutes and then shut it off and use a marine motor de-carb solution( spray it into each cylinder with the piston at the top, let sit for 15 minutes, repeat for the other cylinder. ) then run the engine for another 30 minutes to clear it out. It is wise to replace the impeller too, cheap insurance.

 

[Sailpower]

Re: New to Johnson 15hp

Thanks, the guage I used is a screw in one, but may be a little out - still prob not over 100psi, but with the bores dry and maybe gummed rings, it might explain th elow reading, Happy to lift the head, but didn't want a full rebuild unless its unavoidable.

The kill switch is missing but I separated the wires carefully so they don't ground anywhere or with eachother.

I've got to shorten the longshaft to use it as a short shaft, so I can do the impellor then, or replace the whole pump and seals to avoid leaks. Does it pay to run any descaler through the waterways to lear them?
Thanks again

 

[all duck'd up]

Re: New to Johnson 15hp

Hi - is there such a thing as an ex limey? lol

Anyway thanks for the tip. I got a can of combustion chamber cleaner by Quicksilver for another engine think its called sea foam in the states/Canada, but the motor needs to be running to use it. Do you think Meths would do it, or 2 stroke oil, or better use a proper product?

if they are gummy sea foam has a aerosol can called Deep Creep i would spray some in and let it work for a bit then spin it over a few times with the plugs out then repeat a few times.

sea foam is no joke! i try to run a 3rd of a gas treatment can threw every tank of gas

 

[AlTn]

Re: New to Johnson 15hp

sea foam itself comes in a spray form now..complete with a U shaped straw making it easier to get into the carb throat..good stuff

 

[Sailpower]

Re: New to Johnson 15hp

Does this Sea Foam product (or other similar products) need any special clean out proceedure, or does combustion get rid of all of the active ingredients?

 

[Sailpower]

...

 

[AlTn]

Re: New to Johnson 15hp

no clean out necessary...look under the Top Secret Files at the beginning of the Forum for decarbing instructions using Seafoam...I'd guess all outboard manufactures have some type decarbing agent with detailed instructions provided

 

[sailorboy]

I need help please!

I need help please!

I ordered rings for my 1956 johnson 15HP motor and they were too big. I have been unable to find the right part number for the original 2.375" rings. Would anyone be able to tell me where I can find the part number so i can order new rings or a website where I can look up the part number by year and HP of the motor? Thanks for any help you can give,Sailorboy