OH please Help Mercruiser 5.0 HPi

[BajaOutlaw20]

I have a 2002 Baja Outlaw 20 with a 305 mercruiser 5.0 hpi with alpha drive. Boat has 180 hours and has been maintained. A couple of months ago I used the boat and flushed it as usual with fresh water and put it to bed. Two weeks ago I went to take it out and it wouldnt start. It just clicked. My first thought was the batteries so I replaced them with 2 brand new Interstate 850 cca batteries. It still clicked, so I removed the starter and had it bench tested which came back bad. I replaced it with a brand new marine starter and it still clicks. So I thought I should replace the solenoid on top of the engine and I did with a brand new solenoid and it still clicks. I tested the voltage at the batteries and it was 12.4 volts. I tested the voltage at the solenoid hot side which was 12.4 and the turned the key and got 12.4 on the downstream side. I tested the voltage at the starter and it is 12.4 volts. Somebody had suggested I pull a couple of plugs and see if the motor would turn over thinking maybe the engine was full of water from a bad manifold but, its dry and I can manually turn the engine over and the cylinders are dry as well as the oil looks new. What the hell am I missing here. Can anybody help me please.

 

[z284u2try]

Re: OH please Help Mercruiser 5.0 HPi

those voltages look on the low side for new batts. I would clean all batt contacts first. Check and see if it turns by hand with a break bar and the crank pully bolt.

You can pull all 8 plugs and if doesn't spin when trying to start something is wron with the bottom end.

 

[Zackman]

Re: OH please Help Mercruiser 5.0 HPi

Okay, stop just replacing stuff, unless you enjoy that. ​

Attached are two test from the Mercruiser Manual that should been done before you do anything additional. Do the starter motor voltage test first and then the Voltage Drop test if needed.​

 

[Fun Times]

Re: OH please Help Mercruiser 5.0 HPi

You also need to see if you have 12v at the yellow with red strip wire down at the starter while cranking. make sure the kill switch is 100% in the run spot. check all fuse at engine and helm. are you getting power at the dash? All so fined the main wire harness coming from the helm and pluged in to the engine, It will be a bigger black rubber looking plug, Pluged in to the engine some times with a hose clamp on it. Try wiggling it around and make sure it is pluged in all the way, And if you can at the same time have some one eles hold the key to start while you wiggle it and also all the other wires on the engine and around the engine area that you can find making sure they are clean and tight.Good luck with it.

 

[Glastron_V210]

Re: OH please Help Mercruiser 5.0 HPi

1 thing to check is the ground from the block to the batteries.

The starter gets its ground from the block, so if this is marginal it will act like a weak battery/starter as you have witnessed.


Chay

 

[Bondo]

Re: OH please Help Mercruiser 5.0 HPi

1 thing to check is the ground from the block to the batteries.

The starter gets its ground from the block, so if this is marginal it will act like a weak battery/starter as you have witnessed.


Chay

Ayuh,... Exactly,... The circuit needs 2 legs to stand on,.. The (+) Positive, and the (-) Ground...

People who Check things before buying parts Usually forget All about the Grounds...
Other folks just start Buying Parts,...
And,...
Hopefully in the process of Totally Replacing the complete electrical system on the boat,...
Somebody might wiggle a Ground wire by accident,+ Everything springs to Life....
That's when the last replaced part becomes the Culprit,+ life goes on,.. For awhile anyways...

I believe,....
Untold BaZillions of Starters,+ Especially the Remote Solenoids have been thrown away for No reason at All...
The Remote Solenoids are Tossed daily, Only because it's Easy to get too....

OK,... Rant over,... See ya.....