1986 OMC 4.3 Cobra outdrive

[Mach1Boater]

The last time i had the boat out i was cruising down the river and it seemed like it ran out of fuel. I got it towed it went to the gas station filled her up (only took 6 gallons so it wasnt empty) took it home and tried to fire it up. The bpat started ran for about 10 seconds and died. It will do tgis every time. Any ideas whats going on? When it is running for the 10savannah seconds or so its running rough as heck.

 

[southkogs]

Re: 1986 OMC 4.3 Cobra outdrive

Dunno' about the Cobra, but just recently my Stringer did something similar to me. Turns out my upper gear case is seizing up - not completely locked, so it would spool up but it wasn't turning free and would choke the engine out.

I'm still sorting out parts to tell you how the story ends on mine.

I figured it out by taking my drive off, but I think that's harder on the Cobra (never owned one).

 

[Mach1Boater]

Re: 1986 OMC 4.3 Cobra outdrive

Thats what i was scared of.

 

[sea wolf]

Re: 1986 OMC 4.3 Cobra outdrive

The last time i had the boat out i was cruising down the river and it seemed like it ran out of fuel. I got it towed it went to the gas station filled her up (only took 6 gallons so it wasnt empty) took it home and tried to fire it up. The bpat started ran for about 10 seconds and died. It will do tgis every time. Any ideas whats going on? When it is running for the 10savannah seconds or so its running rough as heck.

You getting gas to the carb?

 

[southkogs]

Re: 1986 OMC 4.3 Cobra outdrive

Thats what i was scared of.

Like Sea Wolf is asking, don't jump straight to a pooched gear case - eliminate logical steps first. Like I said, I don't know about the Cobra, but I can have the Stringer drive off in about 15 minutes. Makes it real easy to see who's running and who ain't - In my case the engine died with the drive on, and didn't with the drive off: jazz hands to the stern drive!

Is it easy (relatively) to get a cobra drive off a boat? (and put back on)

 

[shortyjacobs]

Re: 1986 OMC 4.3 Cobra outdrive

Like Sea Wolf is asking, don't jump straight to a pooched gear case - eliminate logical steps first. Like I said, I don't know about the Cobra, but I can have the Stringer drive off in about 15 minutes. Makes it real easy to see who's running and who ain't - In my case the engine died with the drive on, and didn't with the drive off: jazz hands to the stern drive!

Is it easy (relatively) to get a cobra drive off a boat? (and put back on)

Pulling a cobra is simple. 6 nuts, and it's off. You need a new gasket to put it back on. A strong back, a hoist with an eyebolt into the oil dipstick hole, or a cobbled together 2x4 frame to hold the drive as you slide it off is super helpful.

What I'm wondering is, can you run the engine with the drive off? Obviously you don't have to worry about melting the impeller without water flow, (it's in the drive), but do you have to worry about the rest of the water system running without water flow?

OP, to me it sounds like it could be fuel related too...Is the carb clear? Choke functioning as expected? Do you have a way to check fuel pressure?

 

[Mach1Boater]

Re: 1986 OMC 4.3 Cobra outdrive

It does the same thing in nuetral. I was origonaly thinking fuerl as well it almost like the carb is full and it euns out. When i pump the trhrottle everyything seems to be functioning fine with the squirt of fuel and everything. It will start everytine i want it to tgen die i will look intthe choke tomorrow. But

 

[Mach1Boater]

Re: 1986 OMC 4.3 Cobra outdrive

But im completly lost

 

[Mach1Boater]

Re: 1986 OMC 4.3 Cobra outdrive

I dont gave a way to check fuel pressure... i can go to auto zone and get a pressure teater

 

[shortyjacobs]

Re: 1986 OMC 4.3 Cobra outdrive

Whether or not it does it in neutral does not necessarily rule out the outdrive upper gear box....even in neutral there's stuff spinning in the outdrive.

Regardless, that's tricky, I'd say attack the easy stuff. You can rent or buy a fuel pressure tester....and look up the specs for your engine fuel pressure. You can also check vacuum on the gas tank side of the pump, and look for an air leak. Here's a good guide: http://forums.iboats.com/showthread.php?t=283269 .

 

[BigJohnMech]

Re: 1986 OMC 4.3 Cobra outdrive

how did you make out with your drive? if you pull the four bolts off the top cover you'll see the gears, just be careful of the oring and when you re-install put a little vaseline on the oring and it wouldn't hurt to put blue lock tight on the bolts.
becareful when tightening the bolts its just an amlu. housing.

 

[Lakes84]

Re: 1986 OMC 4.3 Cobra outdrive

Sounds like an issue I just had. Check your carb fuel filter, mine was clogged.