1996 Johnson 150 won't start in water

[dnifedem85]

I have a 1996 Johnson 150hp Ocean Runner outboard. The last three times I took it to the lake and put it in the water the engine won't start. I remember to prime the throttle and when I turn the key nothing happens. If its in neutral, it sounds like it wants to turn over but doesn't. However, when I take it home and put the flushing clamp and hose on, the engine starts first try. Does anyone know why this is happening or is it just bad luck? Thanks for the help...

 

[Joe Reeves]

Re: 1996 Johnson 150 won't start in water

You say "it sounds like it wants to turn over", also "when I turn the key nothing".

Are you saying that the starter does not turn the engine over, or that the starter is turning the engine over BUT will not start. There is a difference.

 

[Old School]

Re: 1996 Johnson 150 won't start in water

not real familiar with your exact model.....but i have heard of some models having a pressure switch after the impeller (water pump). if the switch isn't activated, either because of a bad impeller or switch..... the motor won't start as a safety precaution.
the engine starts with the muffs because the water pressure being provided to the engine, from the hose, is enough to trick the switch (and therefore the engine) into thinking everythings running as it should.
my bet is on the impeller......whens the last time it was changed and have you driven through anything that could have clogged it up?

 

[dnifedem85]

Re: 1996 Johnson 150 won't start in water

When I say "nothing happens", I mean the engine does not make a sound, it dead. When I say "it wants to turn over" you hear the engine sound like it is about to start but doesn't so I release the key to avoid flooding. Thanks for any help..

 

[dnifedem85]

Re: 1996 Johnson 150 won't start in water

One more thing, the pee stream from the engine is normal pressure, does that rule out the water pump theory?

 

[Old School]

Re: 1996 Johnson 150 won't start in water

re: pee stream

yes..... it rules it out as long as it does it on it's own (in the water) if it does it with a hose and muffs then no, it doesn't rule it out
and no matter the outcome, it is suggested that you change the impeller every 2 years. don't wait till it stops or it'll cost ya

 

[Joe Reeves]

Re: 1996 Johnson 150 won't start in water

Turning the key and absolutely nothing happens, no click, no starter engagement, nada, zilch...... and apparently this is an intermitent happening, that sounds like the neutral safety switch is slightly out of adjustment. Jiggling the throttle/shift handle slightly usually and temporarily cures that problem. I say apparently intermitent due to your statement that makes one assume that sometimes the solenoid and electric starter engages properly and at other times it does not.

The engine must crank over at least 300 rpm in order for the stator under the flywheel to provide the voltage to energize the powerpack (ignition). A slow cranking engine will have weak erratic or no ignition, as follows.

(Engine Won't Start or Hard Starting In Water)
(Joe Reeves)

The Evinrude and Johnson engines, starting in 1973, have what is called Magneto Capacitance Discharge ignition, self contained, not dependent on battery voltage. The engine must turn over at least 300 rpms in order for the flywheel magnets rotating past the stator ignition generating coils to supply approximately 300v AC to the powerpack(s), which in turn is needed to supply power to the coils etc etc (spark).

In the water, exhaust back pressure is encountered due to the fact that the exhaust housing (housing between the powerhead and the lower unit) is filled with water. This would drag down the needed rpms, affecting ignition.

Normally the clue to this type problem is that the engine starts fine on a flushette (hose), but is very difficult to start when in the water.

Should this be the case, check the battery, clean and tighten all conections (use a wrench or pliers, not your fingers). Any cable that gets overly warm or hot indicates either a loose, or tight but dirty, or internally corroded cable. And of course check the starter itself.