New member, 1985 25hp Johnson Questions

Alangaq

Cadet
Joined
Oct 14, 2009
Messages
7
Hi there! I have been poking around on the forums for some time now (search feature works great) and have found a great deal of info, but I have come up short on a couple of topics.

I have a new to me, used 1985 two stoke 25hp Johnson, model # J25RCOS that is manual start and short shaft. I am hoping that someone can tell me what would be needed to make this motor capable of charging a small battery to run some basic electronics like a fish finder, or maybe charge a hand held GPS or VHF.

This engine came with a early 80?s 15? Zodiac MKIII GR and both will likely need some work as they have been stored for over 10 years. So, I don?t as yet even know if the motor runs, although I have pulled it thru a number of times and inspected the visible portions of the pistons and cylinders thru the spark plug hole and did not see anything that would indicate a scored wall or melted piston. I plan to hook her up and test run it this weekend in a garbage can full of water (if she will start), but regardless of the results will be taking it to the local outboard guru to have the impeller replaced, compression check done, fuel pump diaphragm replaced, and everything checked out.


I am quite concerned that this particular engine does not seem to have a tethered kill switch installed? instead it has a push button kill switch on the front panel adjacent to the primer. Is there an aftermarket type kill switch that I can add? And does it have anything from the factory that would prevent it from being started in gear? I don?t think it does?


I live in Anchorage AK and the primary planned use for this set up (early 80?s 15? Zodiac MKIII GR) will be for short fair weather family (5 total, me, the wife, 6, 4, & 2 year olds) fishing trips in fresh water lakes, Cook Inlet and PWS out of Whittier, Seward, Deep Creek and Homer. Never out of sight of land? and as I said, only with good weather! Additionally this set up will be used for a once a year fly-out lake hunt. It may also see use on the big and little Susitna rivers, but not until I get the hang of using it and driving it around on open water. That said, I have been told by several persons that the ?Rock Hopper? prop and skeg protectors are the way to go for what I want to do, so if anyone can refute that, or confirm it, that would be great!

Also, any other bits of advice or cautions regarding this motor that you would care to offer would be graciously accepted and appreciated!

Thanks in advance for your help.
:D
 

bktheking

Vice Admiral
Joined
Jul 29, 2008
Messages
5,057
Re: New member, 1985 25hp Johnson Questions

Your motor is a rope start motor, unless it's electric start there is no provision for a charging system, stator or recifier etc. Not to say you can't add one but it wouldn't be cheap. Your easier and cheaper approach is to get a deep cycle battery with either a decent sized solar charger or battery charger. Looking through the hole of the spark plug won't show a whole lot, doing a compression check would. If reading's are low then pulling the head is in order, that would show much more than a flashlight through a sparkplug hole. A lot of these smaller motors don't have teathered kill switches installed, you can just buy on and wire it up to the existing kill switch wires.Pro Design makes a switch for ATV's that you could mount on the tiller handle, piece of cake. They are called lanyard switches btw.

10 Years not being run, replace water pump, thoroughly clean the carb and put a kit in it, drain and replace the lower unit gear oil. I'd check for spark on both cyclinders before anything along with compression.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: New member, 1985 25hp Johnson Questions

I don't think you can make it charge and if you could the output woud be really low.A heavy deepcycle would run those things for a long while.You may be able to carry some backup batteries for the gps.I believe it has a device that makes it impossible to pull start in gear.If you test it in a barrel be sure the water comes up to the bottom of the mounting bracket as it might on a boat at rest.You might consider not running it as adding fuel and attempting to run it may further complicate servicing the carb as most long stored motors do require.
There should be a tether type kill switch you may even be able to put it in the same hole.
As far as prop protection anything that works.
There was a guy on one of the forums years ago that attached a "potato fork"in front of the motor wondered why the motor ventilaated(cavitated) so easily.Let us know how you make out.
 

Alangaq

Cadet
Joined
Oct 14, 2009
Messages
7
Re: New member, 1985 25hp Johnson Questions

thanks for the great advice guys! I will give it a good once over myself and then take it to the pro's for a thurogh inspection
 

jasper60103

Commander
Joined
Sep 18, 2008
Messages
2,055
Re: New member, 1985 25hp Johnson Questions

If you have an Autozone or Oreilly's up there.
You can borrow a compression tester for free. Also, pickup a spark tester while you're there. They're cheap, only $7-8. Also, before doing a compression test, I would give the the cylinders a few squirts of oil for lubrication and manually turn the flywheel.
 
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