1996 Johnson 25HP 3 Cylinder, Running out of ideas!

megaceryle

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Hey all, great resource here. First time poster but have been using the search function often.

I bought a 1996 Johnson 25 HP (J25TKLEDC) this summer to power a 13' Whaler. When I was shown the motor, it started right up. After bringing it home, I did a few PM things to get it into a little better shape - new plugs, wires, and thermostat. I mounted it and went out for a few rides, after a little bit of a rough start first time in, she ran wonderfully. Cruised out to LIS and back and had a blast.

Third ride, motor started to act like it was being governed. Wouldn't rev any higher going from 1/2 throttle forward. Was stuck right before getting onto plane. So, tried a bunch of fuel line fixes - new tank and line, new fuel filter, still the same. Ripped off all three carbs, rebuilt them (and actually found one with a bunch of schmutz in it, so I was optimistic at this point.)

Put the carbs back on, motor fired right up. Ran it at idle for 10', revved it up, back down, sounds great. Then, got busy (new job, etc. etc.) and a week later go out to test it out again. Starts right up... then dies. Then starts for 5 seconds... then dies. Then won't start. Let it sit a bit, go back, same thing.

Now, moved her into the garage, and can't even get her to start up once (I have a water tank to run it in). I'm running out of ideas. Spark, compression have been fine since I bought it. Even ripped off the oil mixing unit and am running in pre-mixed. Anyone have any ideas I could be overlooking? I hate to bring this damn thing into a shop after all this work...

Thanks a ton,

Brendan
 

AlTn

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

pull the plugs and test compression, record for each cylinder....test each cylinder for spark, 7/16" open air gap...then, on to fuel and fuel delivery. I realize it goes through your mind that the first 2 test are not necessary as you tested them as recently as yesterday, but in my experience ignition spark can be lost at any moment, not so much with compression, but it doesn't take long to check.

How old is the fuel? Is it fresh? Have you pulled a fuel line after the pump and made certain the fuel pump is pumping fuel to the carbs? Possibility you have water in the fuel?

In a " no start" condition, these are the tests I'd start with. Post back with results and many helpful folks will respond.
 

hidef

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

First off get the factory service manual.

Johnson Evinrude Manuals from 1917 to 2007

The compact triples (25 and 35) are a pain in the butt to work on without it because there is so little documentation on the web.

From what you were describing the engine was going in to slow mode. Make sure all electrical connections are tight including the battery connections. Check for spark on all three cylinders if you don't have spark follow the CDI guide page 57 to troubleshoot it. The steps are for the V4 with optical ignition which your engine has but there are no troubleshooting steps for it in the guide. (see my sig for the link to the guide).
 

megaceryle

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Thanks guys. Will recheck spark and compression this evening and post results.

I do have the Seloc manual and it's been helpful so far, especially on the carb rebuild.

Can you elaborate on 'slow mode'? Is this the warning mechanism triggered by low fuel or are there other reasons it will be engaged? I'm thinking of taking all the wiring out of their 'sheaths' (previous owner wrapped in electrical tape) to check for shorts...
 

hidef

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Your engine has a safety feature called SLOW mode. It engages if the engine overheats or if the oil tank and mixing chamber runs out of oil (If the oil tank has not been removed). It will not engage for fuel restrictions because it is not monitored on your engine.
 

megaceryle

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Alright, checked compression again (with a new threaded tester) and got 125 top cylinder, and 110 across the bottom two. I would have hoped for some better consistency, but I really doubt this is enough of a difference to cause a no-start condition.

Spark looked good across all 3 cylinders.

Took off all the wire sheathing and there are no bare wires or shorts.

So... what's next? :confused:
 

clanton

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Where are you at now? No start, low rpms or what. Where and what kind of plug wires did you install? Oil mixing system still on engine or has it been removed. Did you install new water pump, and check the thermostat?
 

clanton

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

You have a multi meter?
 

megaceryle

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Still will not start.

I took off the oil mixing unit this past weekend in an attempt to fix the problem. Also I installed a new thermostat a couple weeks ago. Should I recheck my thermostat installation? Didn't seem like much could go wrong there.

I do have a multimeter, just need some advice on where to use it!

Thanks again everyone.
 

hidef

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Did you unplug any of the wires going to coils? If so you might have crossed them when you put them back on.
 

James R

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Did you remove the oil/fuel pump VRO or did you simply disconnect the oil system. If you kept the VRO for the fuel pump side then you must seal of the oil input connection at the motor and disconnect the electrical plugs from the oil tank and the VRO.
 

hidef

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

James, The small triples (25 and 35) don't use the VRO pump. They use two pulse fuel pumps in series that sends the gasoline to a oil mixing chamber that sits below an oil tank. The oil tank and mixing chamber are under the engine cowl.
 

clanton

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Start here. Check the wires to the primary side of the ignition coil.. Orange/blue tracer top coil, orange/purple tracer center coil, orange/green tracer bottom coil. Old sparkplug wires had a metal core, new wire must have metal core, aftermarket wires do not always have metal core ohms test of sparkplug wires should be close to 0. Sparkplug number QL86C, may have been changed by bulletin.

Check the voltage at the primary side of the ignition coil, red lead to coil, black lead to block/ground. Check at cranking rpms, plugs in, wires connected. Meter set on 400 volt AC scale, non auto range. Times X the results by 1.414. This number should be over 100 volts and the same for the 3 cylinders.

Fuel pumps, the manual says the pumps are not the same.
 
Last edited:

James R

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Thanks for the correction Hidef. Took a quick look at the drawing and thought it was a type of VRO.
 

megaceryle

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Thanks, Clanton! The wires from the power pack to the coils look fine and the spark plug wires pass. I had some difficulty trying to test the primary coil terminal with everything connected though, you know a trick for this?

I tried 'pig tailing' a 14 gauge wire out from under the capped terminal, then gripping that with the positive probe of the multimeter and grounding the black. I got no voltage in either AC or DC mode. Either my method is bad or... The coils or power pack are bad? Is this method also the best way to diagnose a bad power pack?
 

pn

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Pump primer. Right direction? Check for gas in fuel bowls. Check kill switch. Check fuel lines, gas for crud. Install filter. Trying priming with premix.
 

clanton

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Next, power coil output test. 2 orange wires from stator 100 volts or higher,
Then charge coil output test 2 brown wires from stator 300 volts or higher.
 

megaceryle

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

Hey, sorry for the delay. I have still had trouble getting reliable voltage readings with my voltmeter as suggested, but on my last check with the spark tester, the spark was noticably weak and inconsistent. I'm fairly certain that it is an ignition problem at this point. I'm thinking that replacing all 3 coils is probably a good place to start. They're old and corroded and even if it is the power pack, I'm probably going to want new coils anyway.

My question now - when i use the graphical parts locator on the Johnson/Evinrude website, the coil assembly is listed as part

0584826 COIL ASSY.

A number of discount parts websites do not have a replacement for this, but show a replacement for OMC 582508, which looks like this:

Sierra Part #18-5179
Plug in Ignition Coil for Johnson, Evinrude 582508, GLM 72010 - Sierra 18-5179 - iboats

Any difference between the two? Just spend the extra $50 for the set on the Johnson website?

Also, if I do end up replacing these and end up finding out the powerpack is bad, any recommendations on sites that might offer them cheaper than the $434 listed on the J/E site?

Thanks all again! Very much looking forward to posting when this thing finally starts back up...
 

jasper60103

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Re: 1996 Johnson 25HP 3 Cylinder, Running out of ideas!

FYI. "Boats dot net" is a good source for OEM parts and usually cheaper than most places in my opinion.
Hopefully its not the power pack. That thing is crazy expensive. Good luck.
 
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