neutral safety switch

[Portholme]

My boat sometimes starts brilliantly and other times won't fire at all and I'm self -diagnosing a faulty neutral starter switch. if i move the control lever a few times it usually works perfectly but it feels a risky thing for coastal use!

Anyone prepared to shed any light?

Merc 5.0 carbed, alpha 1 and Commander 3000 control lever all 2000

Thanks

PH

[mmwjr]

Need so clarification.

When you say if will not fire sometimes does this mean the engine is turning over but will not start? If so not the neutral safety switch as this will prevent the engine from cranking.

Another fault for cranking issues is a bad slave solenoid.

When it will not start have you verified there is gas at the carb? Spark at the plugs?

[Portholme]

hi

When i say it won't fire i mean it won't do anything, until i waggle the controller and try again and then it starts perfectly. i am pretty certain the neutral safety switch is playing up as it is intermittent. id like some other people's views in case i am barking up the wrong tree.

[mmwjr]

You may be correct but the slave solenoid is the typical problem from what you have described and acts intermittently due to pitted contacts. It is located on near the engine breaker and cost about $25 US.

When it does not work do you hear any clicking? If so the solenoid is the issue.

[Portholme]

Thank you. I will check that too!

[shrew]

I agree with the solenoid diagnosis. However, what is interesting is the description that it is either dead ('click') or if the shifter is giggled, then it starts. The 'click' sounds like a solenoid issue. If that is the case, then hitting the ignition 10-15 times in rapid succession can also knock the corrosion off of the gate contact and get the motor started as well.

However, I'm wonder if there is a loose Shift Interrupt at play here. Wouldn't a shift interrupt being actuated, even if the shifter appears to be neutral also behave the same way?

[mmwjr]

Originally Posted by shrew

I agree with the solenoid diagnosis. However, what is interesting is the description that it is either dead ('click') or if the shifter is giggled, then it starts. The 'click' sounds like a solenoid issue. If that is the case, then hitting the ignition 10-15 times in rapid succession can also knock the corrosion off of the gate contact and get the motor started as well.

However, I'm wonder if there is a loose Shift Interrupt at play here. Wouldn't a shift interrupt being actuated, even if the shifter appears to be neutral also behave the same way?

If the shift interrupt (switch to stumble ignition) were loose the engine would still crank just would not have spark.

If it's a miss aligned neutral safety switch in the shifter there would not be a click.

The OP never answered if he hears a click or not.

[Portholme]

To close the loop for you helpful folk i replaced the slave solenoid and the problem is solved. i then took the old solenoid apart and it was horrible inside, very black on one of the terminals. problem solved for £30!

Next tasks......replace the steering cable, fit new chart plotter, get the water heater working, clean all the carpets and head linings....

[Whitey807]

I found that if you turn the key and nothing happens open the engine hatch and turn the key and listen. If you can hear a light clicking sound coming out of the engine compartment when you turn the key to start the engine then it's the solenoid. Just replaced mine and it works great now.
Tommy O'Hara

[jparsons121]

Keep a spare or two of these around, as the slave solenoid for the starter is also the same that Merc uses on the trim pumps..