Johnson 25hp Won't Start! No Fire to the Plugs!

[JohnandSusan]

Johnson 25hp Won't Start! No Fire to the Plugs!

I recently purchase a 28ft. 1978 Lancer Sailboat and it came with an older Johnson 25hp outboard motor (seahorse). I get gas to the spark plugs, but the spark plugs don't fire. Do I have to remove the fly wheel or can I repair it without removing the fly wheel (problem removing fly wheel) and what are the possible problems and solutions.

Thanks

John and Susan

ps - Do you need a special tool to remove fly wheel?

[ryendube]

simply yes and yes. ignition part under flywheel, and you need a puller. not a claw type but harmonic balancer type ie it has slots that you slide bolts through that thread into the flywheel. center bolt that threads in puller sits atop shaft and as you thread down it pulls flywheel up.

first are you sure your not getting spark? at all? how did you check it.

[tashasdaddy]

what is the exact model # makes a big difference in how you attack the problem.

http://forums.iboats.com/johnson-evinrude-outboards/top-secret-file-updated-8-1-2012-a-299680.html

[JohnandSusan]

I bought the 25hp outboard motor with a boat, so I have no model numbers or information on the motor other than it is a Johnson 25hp ( 1973 to 1989 ) manual pull.

1.) I did remove the fly wheel and the points were not set at all.
2.) Used a guage to set the points at .20 gap
3.) I connected a broken wire running from the points to cylinder 1
3.) Problem #1 - I did use a meter to check the continuity from the points to the spark plugs.
( no reading between the spark plug and transformer like coil? attached to the spark plug with a spark plug cable.)
4.) Problem #2 - when I replaced the fly wheel I pulled the pull rope and It was like stuck? I am sure it's something I over looked, but boy is it frustrating!

Please Help!!!!!

Thanks

John and Susan

[jasper60103]

I bought the 25hp outboard motor with a boat, so I have no model numbers or information on the motor other than it is a Johnson 25hp ( 1973 to 1989 ) manual pull.

Just an FYI...

Where to find your model number:

Johnson/Evinrude Outboards:
The model number tag is located on the top outside edge of the CLAMP BRACKET; or, on top of the SWIVEL BRACKET HOUSING (port or starboard). It's usually a metal tag or a sticker. Often there is a quarter size silver piece with numbers stamped on it.

If you're still unable to find a model number on your engine, (sometimes will be worn off or scratched off), there is a silver core plug on top of powerhead with model and serial # or p/n on power pack can help with determining the year.

Also check on the welsh plug (freeze plug) on the block (power head) for numbers/letters. (If powerhead has been rebuilt or replaced this probably won't help you. (Will only reveal the part number of the new, not original powerhead.

[ryendube]

umm your refering to the sparkplug wire? ya your not going to be able to do a reg continuity test you will be measure=ing resistance not like a reg wire I know in automotive it will be in the Kohm range, umm marine i dont have numbers but they are not like automotive due to the lack of rf sheilding. Solid core resistance i low but still not a short like a reg wire connection.

anyways those transformer type coil thing is a coil. ie an inductor that induces high voltage to the ignition system so "spark" can jump the gap of the plug. (has to do with charge time Voltage drops Current rises magnetic field is created as the voltage is cut off from coil field collapse induce crazy voltage to try and maintain current etc etc etc....)

1st thing you say the motor wont turn over now? you sur eyou put everything back nicely? you touch the coil mount? ie screws stickin up? you change the plugs perchance? something jamming up. take it apart again and take a looksy and will address other problem when you get it together freely.

[JohnandSusan]

simply yes and yes. ignition part under flywheel, and you need a puller. not a claw type but harmonic balancer type ie it has slots that you slide bolts through that thread into the flywheel. center bolt that threads in puller sits atop shaft and as you thread down it pulls flywheel up.

first are you sure your not getting spark? at all? how did you check it.

Hi,

I did pull the flywheel and used a guage to set the points at .20 gap.
I did use a meter and checked out ok from points to the transformer (coil?) that is connected to the spark plug. From the transformer to the spark plug no reading and I used a spark plug tester that test the spark and no spark!

Please Help!!!

p.s. - When I bolted the flywheel back on I couldn't pull the pull rope, as it was stuck and the throttle keep moving from start to low. I didn't torqe it yet, I hope that is it!!!

John and Susan

[ryendube]

Hi,

I did pull the flywheel and used a guage to set the points at .20 gap.
I did use a meter and checked out ok from points to the transformer (coil?) that is connected to the spark plug. From the transformer to the spark plug no reading and I used a spark plug tester that test the spark and no spark!

Please Help!!!

p.s. - When I bolted the flywheel back on I couldn't pull the pull rope, as it was stuck and the throttle keep moving from start to low. I didn't torqe it yet, I hope that is it!!!

John and Susan

umm you must of missed last post of mine but how exactly did you chck spark if 1 you just fixed wire and 2 the flywheel is not moving..... also you tried pull starting with out torqueing the flywheel down???? dood, not good. weither it had gas or not theres close clearances on the flywheel and it could be jammed against something it should nnot be......no if you tried starting it with out torqueing which IM SURE YOU DIDNT please step away from the motor and do not touch it again....

[JohnandSusan]

Johnson/Evinrude Outboards:
The model number tag is located on the top outside edge of the CLAMP BRACKET; or, on top of the SWIVEL BRACKET HOUSING (port or starboard). It's usually a metal tag or a sticker. Often there is a quarter size silver piece with numbers stamped on it.

If you're still unable to find a model number on your engine, (sometimes will be worn off or scratched off), there is a silver core plug on top of powerhead with model and serial # or p/n on power pack can help with determining the year.

Also check on the welsh plug (freeze plug) on the block (power head) for numbers/letters. (If powerhead has been rebuilt or replaced this probably won't help you. (Will only reveal the part number of the new, not original powerhead.

[/COLOR][/QUOTE]

Hi,

I look every where and could not find any model or serial numbers.
I do know it is between 1973 and 1989 Johnson Seahorse with manual pull
2 stroke outboard motor.

I did pull the flywheel and used a guage to set the points at .20 gap.
I did use a meter and checked out ok from points to the transformer (coil?) that is connected to the spark plug. From the transformer to the spark plug no reading and I used a spark plug tester that test the spark and no spark!

Please Help!!!

p.s. - When I bolted the flywheel back on I couldn't pull the pull rope, as it was stuck and the throttle keep moving from start to low. I didn't torqe it yet, I hope that is it!!!

[JB]

As TD said, there are many differences in Johnny 25s over the years. We need to know what year to be of more than simple help.

I hope you meant .020" when you set the points.

You seem to have a model with magneto ignition. There is no connection between the points and the spark plug. The points switch current in the coil primary, which induces spark voltage in the secondary. The Condensors absorb voltage spikes in the points/primary circuit.

You have two ignition systems; one for each cylinder. They share a cam to operate the points and flywheel magnets. Depending on what model you have they may also share a kill switch.

Let us know your model number.

[JohnandSusan]

what is the exact model # makes a big difference in how you attack the problem.

http://forums.iboats.com/johnson-evinrude-outboards/top-secret-file-updated-8-1-2012-a-299680.html

I did pull the flywheel and used a guage to set the points at .20 gap.
I did use a meter and checked out ok from points to the transformer (coil?) that is connected to the spark plug. From the transformer to the spark plug no reading and I used a spark plug tester that test the spark and no spark!

Please Help!!!

p.s. - When I bolted the flywheel back on I couldn't pull the pull rope, as it was stuck and the throttle keep moving from start to low. I didn't torqe it yet, I hope that is it!!!

[ryendube]

"You seem to have a model with magneto ignition. There is no connection between the points and the spark plug. The points switch current in the coil primary, which induces spark voltage in the secondary. The Condensors absorb voltage spikes in the points/primary circuit."


yes but its the collapse of the field that creates the high voltage. Not like a transformer that steps up or down voltage.
that is why you need a condenor, the voltage spike (or spark voltage as you stated) is proportional to the change in flux linkages. No condensor arcing will occur and burnout points.

sorry i rarely get to babble with the useless theory from school.

They are right a model of the motor helps lots but there are some things that can be trouble shooted with out it.

[JohnandSusan]

umm you must of missed last post of mine but how exactly did you chck spark if 1 you just fixed wire and 2 the flywheel is not moving..... also you tried pull starting with out torqueing the flywheel down???? dood, not good. weither it had gas or not theres close clearances on the flywheel and it could be jammed against something it should nnot be......no if you tried starting it with out torqueing which IM SURE YOU DIDNT please step away from the motor and do not touch it again....

I didn't try and start the motor with out torqueing it down, I was testing it to make sure the flywheel functioned properly and it didn't. I wanted to remove it easily in the event I get new information that might solve the firing issue. But I am concerned that it does not pull freely. Is this a result of not torqueing down the flywheel?
I did replace the spark plugs and used a spark plug tester than failed.
I replaced the broken wire after removing the flywheel and setting the points.
It seems like the coils failed, but for 2 coils to fail?
The engine does have a kill switch that is share by both cylinders, but the kill switch was damaged before I got the engine.

Thank You Very Much For All Your Help!!!

I Appreciate All Your Advise

Thanks

John and Susan

[JohnandSusan]

As TD said, there are many differences in Johnny 25s over the years. We need to know what year to be of more than simple help.

I hope you meant .020" when you set the points.

You seem to have a model with magneto ignition. There is no connection between the points and the spark plug. The points switch current in the coil primary, which induces spark voltage in the secondary. The Condensors absorb voltage spikes in the points/primary circuit.

You have two ignition systems; one for each cylinder. They share a cam to operate the points and flywheel magnets. Depending on what model you have they may also share a kill switch.

Let us know your model number.

Hi,

Yes I did mean .020 to set the points.
Yes there are two ingnition systems , one for each cylinder. They do share a cam to operate the point and flywheel magnets. Yes they do share a kill switch that was damaged before I go the motor.

Thanks for all your help!!

We do appreciate all your advise!

Thanks

John and Susan

[tx1961whaler]

The reason it is not turning freely is that the coils are hitting the flywheel. They must be aligned flush with the flat part of the mounting lug. What's happening is that the flywheel is rotating around and the flywheel magnet is hitting the coil.
There are some instructions here:
http://forums.iboats.com/engine-frequently-asked-questions-faq/how-change-coils-set-points-old-omcs-294072.html

[tmcalavy]

If the ID plate is missing, look around on the powerhead for a round silver plug with numbers on it. Post those numbers and we can ID it, or a photo. Hang in there, not difficult to tune up that type of motor...but the first time can be daunting. As txwhaler said, sounds like the coil heels aren't flush with the casting/lug where the coils sit. Each of the coil heels/ends should be flush with the casting underneath them. You loosen the coil retaining bolts to make the adjustment.