OMC 4.3

[Bills KMV]

Good morning everyone, I have an issue starting my 1989 OMC Cobra 4.3.
When I turn the key no start, (not turning over) no dials light up but the bilge works, tilt works and acc lights work. My batteries are at are 12.9 volt and 13.1 volt.
Just bought this boat last January and its my first attempt at starting it. The seller said it was starting and running before he winterized it. Any suggestions would be appreciated.

 

[alldodge]

Does the boat have a battery switch?

 

[Bills KMV]

No Battery switch

 

[Bills KMV]

I just have one for power and a spare

 

[Bondo]

Ayuh,..... Welcome Aboard,...... Is there power at the battery terminal on the key switch,..??
Did you clean the battery terminals,..??
Both connectors of both battery cables,..??
The battery cable's connection at the starter,..??
The battery cable's connection to the block,..??

 

[nnl1987]

Veryify what Bondo stated and then depending on how long it has been sitting since last start might need to get your starter adjustment tool out and give it a few taps (hit it with a hammer or a rubber mallet half a dozen times).

 

[dubs283]

Along with previously mentioned items:

Check the 10 pin/main harness connection

Verify voltage at main engine harness circuit breaker

 

[Lou C]

Check ignition fuse in the fuse box. The old tabs & fuses get oxidized and then things stop working.

 

[Bills KMV]

Sorry for the late reply, I'll try all of these and get back thanks

 

[Bills KMV]

Raining here in Cape Breton. Will check when suns out. I have obtained a copy of the wiring schematic and need to know the where the 50 amp fuses are located. Thanks

 

[Lou C]

If your T&T works, but no guages come on and no engine crank, I doubt it is the 50 amp fuse. I bet it's the ignition fuse in the fuse box. Same thing happened to me about 8 or 9 years ago. Especially if you have the old style fuse box with the glass fuses. The metal end pieces oxidize and then no current flows even though the fuse isn't blown.
But because you asked, the 50 amp fuses are in a rubber holder right next to the big cannon plug that is mounted to the shift linkage bracket.
Look at this pic, just to the right of the shift cable you can see em, there are 2 if I remember correctly.

 

[Bills KMV]

If your T&T works, but no guages come on and no engine crank, I doubt it is the 50 amp fuse. I bet it's the ignition fuse in the fuse box. Same thing happened to me about 8 or 9 years ago. Especially if you have the old style fuse box with the glass fuses. The metal end pieces oxidize and then no current flows even though the fuse isn't blown.
But because you asked, the 50 amp fuses are in a rubber holder right next to the big cannon plug that is mounted to the shift linkage bracket.
Look at this pic, just to the right of the shift cable you can see em, there are 2 if I remember correctly.
View attachment 398293

Thanks very much for the response. I'm a complete novice at marine engines so could you tell me me the exact location of the fuse box. I'm doing diagnostics on the wiring and the doing the suggestions that were provided earlier by Bondo.

 

[Lou C]

It’s wherever the boat builder put it. Usually under the helm.

 

[Lou C]

You are aware that you have to hook up ear muffs & water hose to the outdrive before starting, correct? Or else you’ll burn up the rubber impeller and overheat the engine & exhaust system….

 

[Bills KMV]

You are aware that you have to hook up ear muffs & water hose to the outdrive before starting, correct? Or else you’ll burn up the rubber impeller and overheat the engine & exhaust system….

Yes I'm aware of that, but thanks for checking

 

[Lou C]

Also before running it make sure your outdrive is full of gear oil. Dipstick is in the top cover. Remember the gears are all spinning any time the engine is running.

 

[Bills KMV]

Thanks Lou So far so good. Checked and cleaned all wires. The ignition itself was loose so when I inserted the key it was at 3 o'clock. I tightened down the ignition switch for the key to be at 12 o'clock turned it to start and bang it started. No idea why. Checked the outdrive and water was coning out from the muffs only. Might not be picking up water.

 

[Bills KMV]

Finally got it running. Adjusted the muffs to get better water flow and it seems to be circulating water although its a dirty brown color. Temp got to 160 degrees and is holding. Also there's a clinking sound when gears are shifted. Now I have to get the gauges working Thanks to all who helped its greatly appreciated.

 

[Lou C]

You should be seeing more water exhausting from under the transom mount. I used to have those muffs and they are too stiff for the pump to suck in adequate amounts of water. I'd quit using those and get something better. I now use the Merc/Quicksilver round ones with the metal rod clamp. What is your water temp on the dash gauge? Should be about 160*F. Clink or clank when shifting on land is normal, it is a sliding dog clutch engagement. You don't want to hear grrrr....CLUNK....but rather single clank.

Dropbox

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[Lou C]

Thanks Lou So far so good. Checked and cleaned all wires. The ignition itself was loose so when I inserted the key it was at 3 o'clock. I tightened down the ignition switch for the key to be at 12 o'clock turned it to start and bang it started. No idea why. Checked the outdrive and water was coning out from the muffs only. Might not be picking up water.

Looks like someone converted it to a Merc 2 piece exhaust system, these originally came with the OMC one piece batwing exhaust. Mine had those, eventually I had to switch to the 2 piece system and used the ones that were used on later OMCs and Volvos.
Here's the old style OMC batwing exhaust:


and what I replaced it with: