OMC Cobra Drain plugs

[travelingfrenchy]

I have an 87 Cobia Monte Carlo 230XL with a 5.7l OMC Cobra I/O. When I got it from the guy, he said he wasn't sure it needed anything. It was winterized and everything but has been started in 4 years. I checked everything over and everything looked in tact. Started up like a charm. No problems cranking at all. I had it running for about 15 minutes and noticed it was smoking white. I turned it off after I saw the temperature rising. The drain plugs were missing. I found two of them but I believe it needs four? how do I know what size I need. I put the two back in the lower ones. I believe I need four also right?

 

[Gilded_Splinters]

I hope you're talking about the drain plugs in the engine block. Either way, there are only 2 as far as I know and they're located in the center of the block on the sides, just above the oil pan flange.

I should also mention that they're not usually plugs at all, but "valves" or petcocks of a sort. Someone could have certainly changed them for basic threaded plugs at some point.

There are 4 plugs in the out drive, 2 of which are used to drain and fill the drive, one to check the level via a dip stick and one that is the dreaded "don't remove me" plug on the opposite (port) side of the drive.

Quick question: While it was running (assuming you had it hooked up to a water source), was it shooting water into the bilge from these plug holes?

 

[travelingfrenchy]

Yes I did mean valves. I am sorry. But I thought there was two. But someone told me there was supposed to be four. Second I did have water hooked up. I put the valves back on today and started it up. Still smoking. And yes I do have water shooting into the bilge. But not from those holes.

 

[Lou C]

Exhaust manifolds each has one too.
If you run the engine with the drain plugs out all the cooling water will drain out and the risers will get very hot. The rubber exhaust hoses will get very hot and you will burn up the rubber exhaust flappers if you have em. Get a manual and read up on re commisioning a boat. You may also have to replace the impeller; it may be all dry and cracked at this point.

 

[Bondo]

Still smoking. And yes I do have water shooting into the bilge. But not from those holes.

Ayuh,...... Welcome Aboard,..... Shouldn't be too hard to find the sources of 2 shootin' streams of water,......

Generally speakin', V-motor's will have 2 block drains, 1 each side, down low center of the block, just above the oil pan,...

The exhaust manifolds have at least 1 each, usually just above/ over the block drains,.....

There may, or may not be other drains, such as for a P/S cooler, or such things,...

Most block drains are 1/4" pipe thread,... Manifolds can be 1/4", or many are 1/8" pipe,... risers also may, or may not have drains,....

If a boat motor is over heatin',.... Changin' the raw water pump Impeller is the 1st step in findin', 'n fixin' the problem,...