Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

[KrazyKyote]

I have an older boat with a 1978 johnson 25 hp sea horse model number is 25E78C motor.. it has no pull start and is only fired by a key.. I looked at the black and yellow wire and cannot figure how to disconnect it , its all harness.. It also has a fully charged battery and no corrosion anywhere and turns over nicely but wont fire.. I'm guessing this motor is electric start so it has nothing under the fly wheel to go bad..I have read alot online about the power pack and un plugging the black/yellow wire but cannot figure it out to diagnose it..The boat did run last time out, that is where it had died on me right at the loading ramp and has had no spark since.. I just figured it was fouled plugs at the time.. Hopefully somone can help..Thanks

 

[Sixmark]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

First you will need to be able to identify your power pack, I will give you a siomple step by step to identify it so don't feel insulted if something seems too simple.

Starting with the spark plug, follow the plug wire from the plug back to the coil pack (the plug wire may or may not be removable, depending on type of coil).

Now look for two wires coming out of the coil pack, they will probably be black and orange, the black being a ground wire which will be attached to the block of the motor. The orange wire will usually tie into a plug with the wire/s from the other coil/s that plug then plugs into your power pack.

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

ok, i got the power pack identified. So how do i test this .? seems like i have power to that point and after that it seems nothing has power. Not sure but i wouldn't think both coils could go bad at once and if im right it doesnt have anything very likely to go bad under the fly wheel.. By the way i apriciate the help..

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

I,m going to post some pics of my motor , and maybe that will help more with the troubleshooting the problem..

 

[Sixmark]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

The black wire with a wellow stripe that you referred to earlier will be on the power pack and it's for the ignition kill circuit. There are actually test procedures listed here on the forum for testing power packs, coils, and the parts under the flywheel as you like to call them....lol, in reality there is a stator and charge coil.

Just do a search on the forum for testing a powerpack, or similar keywords and you will find it, and will walk you through step by step.

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

Sorry for the odd questions, kin of new to fixing marine motors.. But i actually pulled the power pack out and checked all connections for flaws and put it back in and for some reason lightly tapped the coils with the handle of a hammer and it fired up . have spark on both cylinders now.. would tapping the coils have done something ? All the connections looked good. Or can a power pack slowly go out ?

 

[Sixmark]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

Sorry for the odd questions, kin of new to fixing marine motors.. But i actually pulled the power pack out and checked all connections for flaws and put it back in and for some reason lightly tapped the coils with the handle of a hammer and it fired up . have spark on both cylinders now.. would tapping the coils have done something ? All the connections looked good. Or can a power pack slowly go out ?

Questions are how you learn more so it's never a bad thing.......do the coils look old, brittle, and cracked? are the ground conections good and clean and tight?

Power packs can fail instantly or gradually degrade over time, they tend to act up more when warm......are the connections all clean and free of corrosion?

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

sorry , couldn't figure out how to attach photos. But yes all the motors connections are clean from corrosion..The last time it was ran was in 2007, that's when it first quit. I just don't get how by removing the power pack completely and putting in back on it then started.. maybe moving it's ground helped. I read somewhere on here from searching that power packs have a failure mode...? Is this true ? If so what would trigger it ? Thanks...

 

[dew2]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

Doesnt take much corrosion to block a good ground,12V systems the ground is most important,without it no power!

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

I'm back..LOL.. So it started up and was good for several starts and i ordered a new powere pack for piece of mind. Go down and try it no spark with the old or new packs.. What else can i replace or do.. Thanks guys..

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

I need a pro mech to chime in here on some wires.. I think i found my prob, there was a plain brown wire on the small side of the power pack harness.. i seen a little bit of wire showing so i pushed it in and it fired, pulled out a little and wouldn't. So i shoved it in as far as would go and left it..Starts witht the first spark now.. So is this plain brown wire a signal from up above.. Also how to repair that kind of rubber harnes plug..

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

ANYONE..LOL.. I Just want to verify the wire..HELP WITH THE BROWN WIRE.. What is it ? ? Am i right the reason for no spark due to this wire is because it comes from my stator, and it not contacting the pin in the harness would cause no spark..But when pushed in it works.. I believe the brown wire goes form the stator to the harness to the power pack ,then from the power pack to the harness to the coils.. I believe i will make it on the cat fishing trip now on sat.. Thanks for all the support i boats..

 

[Sixmark]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

The brown wire is a connection to the stator, it's not uncommon for the leads to try and push out of the rubber boot, just make sure all are pushed in all the way.

 

[boobie]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

You may want to try CDI electronics.com. You might find a wireing diagram for your mtr. All I can tell you is brown wires usually come from the stator to power the ignition system.

 

[KrazyKyote]

Re: Trouble shooting a 1978 console steer 25hp johnson seahorse w/no spark

Thanks sixmark and boobie.. I have a manual coming in the mail ,it's been on it's way for like 2 weeks..Damn E-bay.. It really is funny how something so simple can make things so difficult. I just wanted to determine the loose brown wire was my loss of spark.. Thanks again fellas..