No crank intermittently-gctid814151

[bbesser1]

I have a 1989 Bayliner Cuddy 2051 with a Mercruiser 5.0 lx engine. I have this issue when I want to start the boat, sometimes it starts right up and sometimes it doesn't. When it doesn't start the gauges lurch forward a little bit but there is no cranking at the starter. It seems like it is not able to find neutral. If I move the throttle control back and forth I can get it to eventually crank but it is not the best situation when out on the lake. Any ideas on where to start? We're new to boat ownership but I have extensive car repair experience. Not real great on testing electrical issues though. Your help would be appreciated.


Attached files

[aluxury1]

There might be an ignition kill switch mounted on the engine near the throttle or shift linkage. There is a cam that open and closes with shift linkage movement, used to kill the ignition for a split second while it goes into and out of gear, to reduce torque while shifting. It might be bad or not mounted properly. Only other thing I can think of is battery connections. Sometimes there is a hard crust built up on the connections. That's an easy fix.! Don't forget the battery switch connections if you have one.

[Ruffryder]

It's the neutral safety switch.

Shift interrupt switch has nothing to do with this if that is what aluxury is referring to.

[Pcpete]

I'm assuming you have one lever that shifts and accelerates the engine. The most common cause I know of for what you are experiencing is the neutral safety switch. If the shifter part of the handle rotation isn't in a position allowing the switch to allow power to the starter, you hit the key and nothing happens. Move the shifter/accelerator handle slightly and it will work just fine. You can replace the switch, but if there is an adjustment, I'd go for that first. Sometimes it's as easy as adding a little grease, others it's replacing a bushing. In a worst case you can bypass the switch, although I don't recommend it, to get yourself home. That requires opening the shifter housing and connecting the two wires that go to the switch. The danger is that the engine will start in gear, not a good plan on an ongoing basis. That's why I don't recommend it except to get you home.

[bbesser1]

There is some gunk on the part you refer to. Is this the area you are talking about? Would spraying it with carb cleaner be safe to clean it up or does it need grease?


Attached files

[Ruffryder]

Leave that alone,

If she is shifting fine

[Chief_Alen]

Neutral switch located in the throttle control

Put up a picture of your control we will talk you thru removing it.

[builderdude]

Good battery cables and connections at both ends are solid, negative cables too?? Look to the slave me thinks.

[Jim_Gandee]

Bbesser,

I'd start with the neutral safety switch for the symptoms you describe but here's a good little troubleshooting flow chart that may help.

http://forums.iboats.com/forum/engin...ystem?t=167035

[baylineguy]

I had the same problem on one of my mercruiser 7.4L engines. It gradually got worse over time. Turned out to be starting solenoid was going bad, likely from a build up of carbon. Replaced that and the problem went away.

[Ruffryder]

Same problem?

You had to wiggle the shift lever to start?

I doubt it...

[builderdude]

"Ruffryder" post=814285 wrote:
Same problem?

You had to wiggle the shift lever to start?

I doubt it...

From his description it does sound like a faulty neutral switch, he would wiggling the shift lever, but that may or may not be the issue. I should have asked if he heard any clicking at the slave solenoid when attempting to start? Thats why a suggested to look at the slave :dry:

[baylineguy]

Yes, sometimes it did start up after I wiggled the shift lever. Turned out it had nothing to do with the shift lever but it seemed like it did at times. I think there was a build up of carbon inside the solenoid and it took several tries to burn through it when trying to start. It was worse after the boat had been sitting for awhile. It was actually a slave solenoid that sat on top of the engine block that controlled the starter. I don't even know if the OP has such a slave solenoid but if he does it can be tested by carefully shorting across the terminals while the key is turned to start.

[Ruffryder]

True, when the slave solenoid goes, could be intermittent.

Easiest way to find out...meter between the 2 small prongs (slave) with the ignition switch on starting position.

[builderdude]

You mean lage posts?