1971 Johnson 25hp Outboard - 25R71S

[Boatbuilds]

Hi all I’m new to the community. I just picked up this motor for free and plan on trying to get it running. It’s a Johnson 25. Checked compression on both cylinders and they are at 125 so that’s good! My next step is to get spark but I have ran into a problem. The motor is missing the Kill Switch/off button. I am not getting spark in either cylinder when pulling the cord. Is this because that part is missing or is it something else? And advise would me much appreciated. This is my first time with a Johnson so it’s a little different then a mercury.

 

[racerone]

Find the 2 small black wires coming from under the magneto.----They should not be connected.-----Remove flywheel and inspect coils.

 

[saltchuckmatt]

Buy any old brand of outboard switches with a man overboard tether and upgrade it. No one should have to see their boat fly away from them.

 

[Crosbyman]

you sould pull the fw anyway to check coils...easy fix if all cracked like picture

change plug wires and boots to ! capacitors likely dead pointscan be "touched up" for a test

refurbish which you should do runs about $150 in parts
coils... points,,, capacitors,,,, carb kit ,,,4 feet of solid metallic strand wire (no carbon fibers) from your local motorbike shop or tractor place

check gear oil for water intrusion refill use new nylons on the vent/oil screws

to service oldies here is a good book to have ...covers everything you need ...ignition, carb gc ph etc.... it says up to 1961 but your engine still has the same basic hardware

1922-1964 Johnson 302231 Outboard Service Manual

Johnson Outboard Motor Service and Repair Manual # 302231 Tenth Edition covers all Models 1922-1964 .pdf download

watercraftmanuals.com

just download and print double sided. 400+ pages

check personnal message in the small envelope top right blue band
good motors good for another 30 years with TLC if innards are ok

 

[Boatbuilds]

Find the 2 small black wires coming from under the magneto.----They should not be connected.-----Remove flywheel and inspect coils.

you sould pull the fw anyway to check coils...easy fix if all cracked like picture

change plug wires and boots to ! capacitors likely dead pointscan be "touched up" for a test

refurbish which you should do runs about $150 in parts
coils... points,,, capacitors,,,, carb kit ,,,4 feet of solid metallic strand wire (no carbon fibers) from your local motorbike shop or tractor place

check gear oil for water intrusion refill use new nylons on the vent/oil screws

to service oldies here is a good book to have ...covers everything you need ...ignition, carb gc ph etc.... it says up to 1961 but your engine still has the same basic hardware

1922-1964 Johnson 302231 Outboard Service Manual

Johnson Outboard Motor Service and Repair Manual # 302231 Tenth Edition covers all Models 1922-1964 .pdf download

watercraftmanuals.com

just download and print double sided. 400+ pages

check personnal message in the small envelope top right blue band
good motors good for another 30 years with TLC if innards are ok

Thanks so much for the reply! Any suggestions on how to get the flywheel off without the proper tool?

 

[racerone]

Nope.----You need a puller with 3 bolts ( 1/4-20 ) to get the flywheel off.-----

 

[Crosbyman]

you either invest in the real McCoy OEM puller $$$$ or just go simple harmonic puller $$ which will do the job
see mine with inverted nylon nuts to prevent going to deep in the FW and hitting coils

lots of utubes on refurbishing standard OMC magnetos.

when do adjust timing. may seem complicated but isn't

 

[tphoyt]

I made a puller from a mini golf flag holder 40 so
E odd years ago and it’s still working fine. There is more than one way to skin a cat. I’m sure if you look on the web you can find some homemade puller ideas if you don’t t have the funds to add to your tool collection.

 

[racerone]

The hole to the right of the word ---STOP----Is for the electric start plug.-----To me it appears that work has been done and motor is not factory original.-----Model # on the plate is ?----Picture of the plate ?

 

[Boatbuilds]

The hole to the right of the word ---STOP----Is for the electric start plug.-----To me it appears that work has been done and motor is not factory original.-----Model # on the plate is ?----Picture of the plate ?

model number: 25R71S Serial Number: E3435249

 

[davidmbv]

Make sure the kill switch wires are not grounded or touching anything. I found a kill switch for cheap on eBay. Get a spark tester to check spark, one that you can adjust the gap.
Lots of info online about these motors . I also have a 71 25hp Johnson. Loved it so much I picked up a 70 and 72 25hp for cheap. About to pick up a 69 20hp for 100$. Want the starter parts off it.
Anyway, eBay has the original factory service manual for your motor for cheap. Good investment.
You can also use a voltage meter to check plug wires, adjust points, check coils, see YouTube videos for how to do. A flywheel puller is a must if you’re going to keep that motor. Can also rent one from auto parts store. Change impeller and gear oil. Have fun, my 71 pushes my 13’ Gregor 27mph.