90HP Evinrude Choke Question

[Hvymtl]

I recently bougth a boat with a 1999 90 HP Evinrude SPL (non VRO). The only way I can get it to start cold is to take off the motor cover and turn the choke (red switch) to prime. After the motor starts I turn it back to normal and everything is fine....sort of a PIA to take the cover off each time. What does the push-in choke do on the key switch? Or is the SPL a cheap model with no electric choke? Is this the starting method I'll need to use all the time?

 

[Joe Reeves]

Re: 90HP Evinrude Choke Question

(Proper Starting Method)
(J. Reeves)

NOTE: If your engine is equipped with an electric ckoke, substitute the words "Electric Choke" in place of "Primer Solenoid".

Cold Engine: Pump fuel primer bulb up hard. Increase throttle somewhat with whatever type control you might have. Turn key to start position. As engine cranks over, push in key to activate fuel primer solenoid. When engine fires/starts, release the key. Should engine start to die out, push key in (just a tap) as needed to activate primer solenoid in order to momentatily increase the fuel flow.

Warm engine: Pump fuel primer bulb up hard. Turn key to start position. When engine fires/starts, release the key. If engine does not fire/start within 6 revolutions, push in key to activate fuel primer solenoid as needed.

This is assuming that the engine is as it should be in all respects (Compression, Ignition, Carburetion, Fuel Supply, etc).

(Fuel Primer Solenoid Function)
(J. Reeves)

The RED lever...... The normal operating/running position is to have that red lever positioned over top of the solenoid and aimed at the other end of the solenoid, gently turned to its stop. This is the normal/automatic mode position. Pushing the key in opens the valve within the solenoid allowing fuel to pass thru it in order to prime and start the engine. Looking upon this solenoid as a electric choke results in a better understanding of it.

Having that red lever turned in the opposite direction, facing away from the solenoid, allows fuel to flow thru it to the crankcase area. One would only turn the red lever to this position in a case where the battery might go dead and the engine had to be started via the rope pull method. Look upon putting the red lever in this position as moving a choke lever on a choke equipped engine to the full closed position. Either one would supply fuel to the crankcase/engine for starting purposes BUT if left in that position while running would flood the engine.

The later model primer solenoids are equipped with a schrader valve, used for attaching a pressurized can of fogging oil etc, available at your local dealership with complete instructions.

Pumping the fuel primer bulb up hard fills the carburetor float chambers of course, but that process also applies fuel pressure to the primer solenoid.

The two small hoses leading from the primer solenoid branch off via tees to each fuel manifold section that would feed fuel to the individual cylinders.

Pushing the key in activates the primer solenoid to allow fuel to flow thru it to the intake manifold passageways. Cranking the engine over causes the fuel pump to engage which in turn sends fuel pulses to the primer solenoid via the 3/8" fuel hose.

Some engines incorporates the "Fast Start" feature which automatically advances the spark electronically so no advance of the throttle is required for starting.
Engines that do not have the "Fast Start" feature will be required to have the throttle advanced slightly.

Starting procedure: pump fuel bulb up hard, crank engine and push the key in at the same time. When the engine fires/starts, release the key so that it falls back to the run position.

Bottom line..... Look upon the primer solenoid as an electric choke.

 

[Hvymtl]

Re: 90HP Evinrude Choke Question

(Proper Starting Method)
(J. Reeves)

Cold Engine: Pump fuel primer bulb up hard. Increase throttle somewhat with whatever type control you might have. Turn key to start position. As engine cranks over, push in key to activate fuel primer solenoid. When engine fires/starts, release the key. Should engine start to die out, push key in (just a tap) as needed to activate primer solenoid in order to momentatily increase the fuel flow.


Bottom line..... Look upon the primer solenoid as an electric choke.

Thanks much... so if motor will not start with red switch positioned across the solenoid, but will start in other direction right away.... I have a problem......maybe there is no power going to the solenoid...I'll check

Does any one know what color the primer wire is coming off the throttle control?

 

[Joe Reeves]

Re: 90HP Evinrude Choke Question

Primer wire is normally a purple wire with a white stripe. It should be attached to the "C" (choke) terminal of the ignition switch.

To test the primer solenoid.... Find one of the small hoses leading from the primer solenoid to the carburetors/intake manifold and remove it from the carburetor or intake manifold.

If you decide to remove it from the primer solenoid, be extremely careful. If you break off one of those small tips from the solenoid, a new solenoid will be required.

Now, with one of those hoses removed.... Engine not running but have the key in the run position, Pump primer bulb up hard, Observe the free end of the hose you removed, Push the key in... Fuel should have shot out of the end of that hose when you pushed the key in which would indicate the solenoid is working just fine.

You should also hear a click when the solenoid is engaged BUT the click is a very soft quiet click... be very close to it.

The proper (automatic) position of the RED lever is for it to be turned completely so that it is facing the other end of the solenoid.

 

[Hvymtl]

Re: 90HP Evinrude Choke Question

Thanks Joe. have power to the solenoid with key pushed in. Do not hear a click at all. Ohm meter reads short when reading between the purple wire and ground on the solenoid...

looks like the solenoid is dead.....

 

[Joe Reeves]

Re: 90HP Evinrude Choke Question

With the fuel primer bulb pumped up hard, one small hose off the solenoid, key in RUN position, did fuel shoot out of that hose when you pushed the key in?

This test you mention... the purple wire from the engine wiring harness would need to be disconnected to obtain a proper reading.

A ohm meter connected between the purple wire "of the solenoid" and the ground lead "of the solenoid" would normally register a reading as that would indicate the solenoid windings are okay.