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88 OMC Cobra: Muff Test Questions

D

DavidBall

Member
I recently tested my (new to me) boat with the water muffs and I'm a little unclear where the water should be exiting the drive, both with engine off and running. I attached a crappy video of the muff test.

With gardenhose on and Engine NOT running:
Some water is naturally coming out side of muffs, but a large portion is coming out a joint in the lower unit below the impeller case but just above the inlet screen. I understand that with the impeller not turning, the water can pass that point, but how can there be an outlet there? Just worried that a tube or hose may be broken.

With gardenhose on and Engine running:
Some water is still coming out the lower unit, but now as one would expect, water is coming out the exhaust. On my boat, I assume the exhaust is the holes on the bottom of the 4-5" corrugated pipe from manifolds to the drive.

Does anyone know where I can find a diagram that explains the path of raw water through the drive?

[video]https://plus.google.com/u/0/photos/110294699167006583324/albums/5912361127779293073/5912361126945545090?authkey=CJf637yHgcvpqgE[/video]
 
88 omc outdrive flow.jpg
In case the video didn't upload right, here is a sketch of my concerns.
 
It's easy enough to seperate the drive 1/2s
The grommets could be melted?
Get a gasket kit so you can replace the o-rings and seals.
Some exhaust bellows have holes in the bottom of the bellows.
Tilt your drive all the way up and look up inside and see if there are holes.
Not that hard to remove,drain and inspect the unit.
Make sure the oil is filled the right way. Manual?
 
Thanks for the reply. I will inspect the drive as son as possible. I do have holes in the bottom of the exhaust bellows, and when on muffs I can see plenty of water coming out there. If you can view the video I posted at the beginning of this thread, you can see it comes out there, AND near the anode on front of unit. I let it run for nearly 20 minutes on muffs and the temperature stayed in the green.

I took the boat to the lake this weekend for the first time since I purchased it and watched the temp gauge very closely. My gauge has no numbers, only a green region (from around 5:00 to 1:00) and then a small white region (from around 1:00 to 12:00). After starting the engine, in about 7 minutes, the temp slowly climbed through the green region to the white. When the boat is moving (25-35mph) the temp goes back in the green. But as soon as I idle or go very slow, I'm back in the white.

I'm not sure how to interpret the gauge, but I assume the white region is a warning area. (It could be formerly red and just faded). The boat ran fine as long as we were moving along. We just killed the engine every time we needed to stop, to avoid possible overheating, and enjoyed 3 to 4 hours of boating. But... after stopping and starting the engine so many times, my engine failed to start at the end of the day. We had to be towed in to access ramp. Not sure what is going on with that. It sounded like it just didn't have enough juice to spin the engine. i jumped the starter solenoid terminals to bypass it and the ignition, but only got a 1/4 turn. The alternator appeared to be charging well (at around 14 volts all day) and I saw around 12 volts on the battery. I hope the temperature didnt do anything that would cause my engine not to spin, and that I just need to replace the starter. And I'm not sure how to tell if my engine circulating pump is actually doing its job. Never really know if the thermostat has opened either. The manifolds were just warm enough that I could keep my hand on them for 2 to 3 seconds.

Sorry for multiple concerns in one thread, but I guess they could all be related. Any thoughts?
 
Another thing I should mention... Yesterday on the lake, just before the failed start, we decided to stop, shut off the engine, enjoy a beverage and let the engine cool. We heard something that sounded like water draining around the engine but couldn't tell where it was coming from. After 4 minutes or so, it stopped. Maybe this is normal, but I hadnt noticed that before.

We sat for 10 minutes, with radio on, and then the failed start. I wouldnt think the battery was drained enough from the radio after such short period.
 
Hello sounds like the rubber grommets are cracked or melted or the water pick up tube is bad. The noise from the engine sounds like the water in the block was boiling due to over heating.
 
Thanks. Will check all seals and tubes. Great... Boiling? Really? I hope not. I guess that probably warped the block or at least gaskets? Could that be the reason it won't turn over?? Locked up or hydrolock?
 
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