Road Construction Johnson

Outboard Related Only
User avatar
Mumbles
CYBER SHERIFF
Posts: 3720
Joined: Mon Mar 09, 2015 3:42 pm
Location: Victoria BC

Re: Road Construction Johnson

Postby Mumbles » Sat Sep 09, 2017 11:58 pm

Yup, they have the pressure/vacuum cooling system instead of a water pump. It has to be in motion on a boat to keep cool but there is a way around that. On the bottom of the block there should be a pipe plug which can be removed so a garden hose can be hooked up for running on a stand. They also like an 8:1 fuel mix.
Still searching for a rudder and hardware to fit a KOBAN. ☺

Member of the http://uppercanadachapteroftheaomci.yolasite.com/

User avatar
Bullie
Posts: 437
Joined: Wed Nov 11, 2015 9:44 pm
Location: Hernando, MS

Re: Road Construction Johnson

Postby Bullie » Sun Sep 10, 2017 9:58 am

Thanks Mumbles! I appreciate the info. Strange with the 8:1, it doesn't smoke as much as I would have expected.

Kinda cool to get this one going.
The Paterfamilias of Modern Squirrel Hunting
Current B&S World Record Holder 1.96 B&S points taken in the Mississippi Hills.
QSMA President/Founder and resident expert on all things squirrel.

User avatar
Bullie
Posts: 437
Joined: Wed Nov 11, 2015 9:44 pm
Location: Hernando, MS

Re: Road Construction Johnson

Postby Bullie » Fri Feb 16, 2018 9:40 am

Ok. Back to this one. I took it out for a spin and it lost spark on one cylinder. I pulled the flywheel and cleaned the points again but still have no spark on that cylinder.

So for my green guy questions. How do I check a coil that doesn't have connections I can loosen? And, I was thinking it may be the condenser going bad. They are under the mag plate? Availability?
The Paterfamilias of Modern Squirrel Hunting
Current B&S World Record Holder 1.96 B&S points taken in the Mississippi Hills.
QSMA President/Founder and resident expert on all things squirrel.

User avatar
Richard A. White
CYBER SHERIFF
Posts: 1383
Joined: Mon Mar 09, 2015 3:43 pm
Location: Kendallville Indiana
Contact:

Re: Road Construction Johnson

Postby Richard A. White » Fri Feb 16, 2018 9:57 am

Those need to be on a moving boat to cool properly....

Richard A. White
AOMCI Member
MOB Chapter President
http://www.richardsoutboardtools.com

User avatar
Garry in Tampa
Posts: 2572
Joined: Mon Mar 09, 2015 2:32 pm
Location: Florida

Re: Road Construction Johnson

Postby Garry in Tampa » Fri Feb 16, 2018 10:55 am

Early models had a single coil and two flats for the breaker points. The flywheel acted as a distributor, shorting out the un used spark plug wire. I am not sure when they switched to the two coil system. If it has a single coil, look for a short in the distributer system. Cleaning usually fixes it. . . :)

Image
Living my dream because Reality is too expensive . . .

User avatar
Bullie
Posts: 437
Joined: Wed Nov 11, 2015 9:44 pm
Location: Hernando, MS

Re: Road Construction Johnson

Postby Bullie » Fri Feb 16, 2018 11:43 am

This one has two coils.
The Paterfamilias of Modern Squirrel Hunting
Current B&S World Record Holder 1.96 B&S points taken in the Mississippi Hills.
QSMA President/Founder and resident expert on all things squirrel.

User avatar
Mumbles
CYBER SHERIFF
Posts: 3720
Joined: Mon Mar 09, 2015 3:42 pm
Location: Victoria BC

Re: Road Construction Johnson

Postby Mumbles » Fri Feb 16, 2018 12:46 pm

Bullie wrote: How do I check a coil that doesn't have connections I can loosen?


You can't. Well you can but it's better to break out the tools and undo the coils primary lead at the points. The other way would involve isolating the condenser from ground and preventing the points from making contact before hooking up your meter.

If my memory serves me right, I think the square caps in my KA-37 were good and didn't need replacing. If I did swap them out, I would have used these .22 uF Vishay caps from Digi-Key which I have used successfully in many motors.


https://www.digikey.com/products/en?ven ... =bc2609-nd

I think this mag was out of a KA-38 so it should be the same as yours.
Attachments
IMGP1797.JPG
IMGP1797.JPG (2.84 MiB) Viewed 339 times
Still searching for a rudder and hardware to fit a KOBAN. ☺

Member of the http://uppercanadachapteroftheaomci.yolasite.com/

User avatar
Bullie
Posts: 437
Joined: Wed Nov 11, 2015 9:44 pm
Location: Hernando, MS

Re: Road Construction Johnson

Postby Bullie » Fri Feb 16, 2018 1:04 pm

Yep. Looks like that one.
The Paterfamilias of Modern Squirrel Hunting
Current B&S World Record Holder 1.96 B&S points taken in the Mississippi Hills.
QSMA President/Founder and resident expert on all things squirrel.

XR55
Posts: 157
Joined: Mon Mar 09, 2015 3:44 pm

Re: Road Construction Johnson

Postby XR55 » Fri Feb 16, 2018 2:09 pm

This motor has no water pump, running in a barrel will over heat the motor. It uses forward motion of the boat and the prop wash to force water into the water scoop to fill the water system and gravity to make the water to flow though the cooling system. When running on a boat, start the motor and run to full speed on plane to purge air and start the cooling water flow. after doing this you may slow down and idle along, but do not make a hard turn at idle as you will interrupt the cooling flow and start over heating. It's called a pressure vacuum system.

Mike Stroz
Posts: 206
Joined: Mon Apr 06, 2015 10:52 am
Location: Massachusetts

Re: Road Construction Johnson

Postby Mike Stroz » Fri Feb 16, 2018 5:02 pm

I really like that series of motors. I run a KA-38 on my 14' rowboat all summer long. Nice and smooth, quiet, and pretty powerful
When in doubt, duct tape!


Return to “Ask A Member”

Who is online

Users browsing this forum: chas56x, Google [Bot] and 5 guests

cron