Let start a I can fix it thread.

[Captmikestarrett]

Capt Dave has an older Evinrude 115 that requires him to hold the shifter controls in a certain position before it will crank over. This weekend the safety lanyard kept falling off. And try as we might the engine would not spark. So I have ordered a new control unit for the boat. New controls include shifter/neutral switch and new key switch. So will this fix the issue of no spark???

More to follow.

Capt Mike

[mikechell]

Sounds like you have a bad neutral switch or activating roller (holding the shifter to get it to start) and a bad emergency stop switch.
There might be a neutral switch on the engine, (like Honda Outboards, which I work on) in which case, you're new control box won't help. You'll need to be sure the one in the control box is the only one.

The new control box will cure your lanyard problem of no spark, though.

[Captmikestarrett]

Well that is the plan to fix it piece by piece. Part will be in tomorrow.
Install on Sunday when we have some time.

Capt Mike

[Captmikestarrett]

Ok new controls and rewired all electrical with breakers. Still no spark on plugs. Did some meter tests and it should work. Unless the power pack is bad, or the rectifier, or the control module...Boat going to the boat shop now..
I am guessing the power pack at just under 400 parts and labor.

Hope I am wrong and it is less.

Capt Mike

[mikechell]

I teach guys how to work on Honda Outboards. But the trouble shooting is the same.
http://www.bassfishin.com/bassfishin...0&d=1446420348

In this case, the changed happened when you were working on the cranking problem. The first place I would be looking is anything that was touched during the cranking/lanyard problem.
With an engine this old though, any change to power electrical power flow can have bad effects on components.

[keithdog]

I wish I could add to this thread but I know nothing about this stuff. Just wanted to let you know I'm still here and reading your posts.

[Captmikestarrett]

Originally Posted by mikechell

I teach guys how to work on Honda Outboards. But the trouble shooting is the same.
http://www.bassfishin.com/bassfishin...0&d=1446420348

In this case, the changed happened when you were working on the cranking problem. The first place I would be looking is anything that was touched during the cranking/lanyard problem.
With an engine this old though, any change to power electrical power flow can have bad effects on components.

The funny thing is Capt Dave kept saying it worked three weeks ago..
I had to jiggle the shiftier and hold the key just right and say the Lords Prayer but it worked.

No more jiggling and holding the key just right. New shiftier and controls installed and the kill circuit has been verified good.

Capt Mike

[Captmikestarrett]

Turned out to be a power pack and power pack sensor. About 600 bucks.
Most older motors will need this repair in the coarse of there life.

Capt Mike

[mikechell]

Outstanding! Glad to hear you got it fixed.

[mikechell]

Of course, if you want to make this a "challenge" thread ... I could give you the symptoms of weirder failures I've encountered. Everyone could then see if they can guess the cause of the symptoms.
No prizes ... I am not that generous.

[mikechell]

Ya wanna try???

V-6, four-stroke engine. 700+ hours on it, but it's been fairly regularly serviced. Engine runs well up to 3500 to 4000 RPM, then dies. It's still electrically active and can be started immediately. This problem happens whether it's in the water or on a hose. The customer states the problem has been like this for a couple of months.

What did we find, that caused this problem? I'll respond to any questions or suggestions whenever I get online. (At least once or twice a day)

[Captmikestarrett]

Air vent on tank was blocked..

Capt Mike

[mikechell]

Good guess, but no. The fuel system was clean.

Also, as stated, the electrical system was not affected.

[mikechell]

Another thing. It runs perfectly up to about 3500 RPM.
You can cruise at 3000 RPM without it ever dying.

But, in that 3500 to 4000 range ... it dies.

[Captmikestarrett]

Secondary diaphragm in fuel pump is ruptured.

Capt Mike

[mikechell]

There is nothing wrong with the fuel system. It functioned and was clean. But, the original troubleshooter went down the same path and replaced several fuel system components. The fuel system is good.
(1) Engine starts readily every time.
(2) Engine runs well at idle, off idle and any RPM below 3500.
(3) When the engine dies, it doesn't "stumble", it just shuts off.
(4) It will start normally immediately after shutting off. The key doesn't need to be cycled, just turn to start and the engine fires up.
(5) On a side note: The only recent work besides normal service was the replacement of a prop shaft seal, which had been cut with fishing line wrapped around the shaft.

[Captmikestarrett]

Just thinking out loud..
If it dies at 3500 and restarts with out on/off to key is has to be some kind of rev limiter or computer malfunction. V-6 4 stroke with only 700 hours on it.. has to be kinda new so a computer malfunction is likely or it has drive by wire and it disconnects at a certain RPM.

I have heard of car doing the same thing and it was the alternator over charging the circuit and the computer shut down..

This is a good one..

Capt Mike

[mikechell]

You're right, Mike ... it was a kick in the pants when we finally figured out what it was.

The tech swapped computers with a known good one ... the problem stayed with the engine. The computer worked fine on another engine. So it wasn't the problem.

Let me know if you want another clue. But the next clue might give it away

[Captmikestarrett]

Yea a clue is needed with out hands on wire jiggling..

Had a 1954 MG that would shut off when it hit a pot hole and then the forward movement of the vehicle would restart it. It turned out to a worn wire on the coil relay..it would ground out on the jolt from the pot hole.. Took me a long time to find it..

Capt Mike

[mikechell]

Okay ... spoiler alert clue. Although, the cause is not the first thing that jumps to mind, usually.
With a scan tool hooked up:
All parameters look fine, even when it dies. But one sensor reading does a very interesting thing just as the engine quits. Just to keep from giving too much away too easily, I'll only say which sensor, not what it does, yet.
The MAP sensor ... hmmmmmmmmmmm.

[Captmikestarrett]

The Map sensor.. Manifold Absolute Pressure. How the heck can that cause a shutdown??

Bad gas mileage maybe but a shutdown??

Riddle me this batman..

Capt Mike

[mikechell]

I didn't say the sensor was bad ... just that it showed an interesting reading.
The MAP showed an extreme drop in pressure just as the engine died.

[Captmikestarrett]

Just about to give up and find the answer but all manifolds have a pressure relief valve in case of backfire.. was that the bad part?

Capt Mike

[mikechell]

Hmmm no manifold pressure relief valve on this engine. But it did have a flame arrestor screen, which stops the flame of a back fire but allows the pressure to vent.

If this is what you're thinking about ... you are VERY close.

[mikechell]

I'll let you try one more guess ... then I'll let you know what we found.