3.0 OMC runs for 30 seconds, once a day

pmpmstrb · Sep 24, 2011

I just picked up a 1984 Playcraft pontoon with a 3.0 OMC with Stringer outdrive. It repeats the symptoms like clockwork.

1. Show up to boat after work
2. Start boat. Fires up just fine. Runs smooth for ~30 secs then stalls (watch video http://youtu.be/EntDRZ_QUKs )
3. Try to restart. Runs/stumbles for 2 seconds. Shuts off
4. Try to restart and all it does is barely turn over
5. No longer wants to turn over, just the starter clicks
6. I fiddle with it, get pissed and go home
7. Repeat from step 1 the next day

I bought the boat knowing that the motor had issues. The way the issues were described to me and the people I talked to we all thought it was a fuel issue. I replaced the fuel pump (mechanical) and filter and checked all fuel lines to the carb. Now it is starting to sound like and electrical issue maybe. I've read some other threads where the issue was a Kill/safety lanyard. I'm not sure if my boat has one. Where is this normally located? Thought it might be the battery, but used a known good unit and same results. Any help is appreciated. If any more info is needed let me know.

pmpmstrb · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

Forgot to mention that compression was fine. From bow to stern it was something like 135, 125, 125, 125.

Don S · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

Sounds to me like you need to charge the battery and rebuild the carb, or at least check the filter in the carb inlet.

Howard Sterndrive · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

That's a hard stop - I think your intermediate or outdrive upper is seizing. Remove the out drive and retry. You can just undo it from the trunnions enough to uncouple the ball gears, and if you are careful to support the drive and not stress the shift cable, no need to completely remove it.
If symptom persists, pull the intermediate shaft and retry.
might be the camera angle, but it looks like you are running it with the outdrive tilted. if so, you may have done some serious damage to the ball gears.
do you have water supplied to the system?

I love the dog's 45 degree head response...

pmpmstrb · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

Yes I am running water through it. That was the only time that it was ran tilted up since I have had it. The other three times it was in the down position. So you are thinking that something in the outdrive is binding causing it to stop and not restart? I'll look into it and report back.

Don S · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

Had to go to a different computer to get sound. The dogs response tells it all. He bailed.

That is not a carb or battery problem.

pmpmstrb · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

So made some progress today thanks to you guys.

1. Showed up and pulled the outdrive back and disengaged the ball gears
2. Boat fired right up and run
3. Pushed the outdrive back against the boat to reengage the ball gears
4. Boat fired up and died in the video
5. Tried again and it wouldn't turn over.
6. Disengaged ball gears again and boat fired up everytime we tried it

So the issue is in the outdrive. Now the question is where do I begin? The ball gear on the outdrive is chewed up. Not sure if that is from me or the previous owners, but it's there. When I tear into this thing where should I start and what do you think I should be looking for? Thanks for all the help so far.

Don S · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

4. Boat fired up and died in the video
5. Tried again and it wouldn't turn over.
6. Disengaged ball gears again and boat fired up everytime we tried it

Did you have the drive down when it quit running the last time?

Might want to post some pictures of your ball gears.

Howard Sterndrive · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

pmpmstrb said:
what do you think I should be looking for?

probably a good used upper gearcase for a 1982-1985 400 series outdrive, and a factory service manual

remove the drive, drain fluids from upper and lower, see what runs out. disassemble and replace/repair as necessary
the fact that it isn't trying to steer hard says upper is the issue and not the lower, but the lower could be junk too, but that's not very scientific...need to disassemble and check parts over.

I'd pressure test the cooling system of the engine before doing anything.

Have you cranked your head upside down in under the manifold to see if it or the block is cracked? looks like a tricky bilge to see in... mirror maybe

pmpmstrb · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

Don S said:
Did you have the drive down when it quit running the last time?

Might want to post some pictures of your ball gears.

It did the same thing whether the drive was up or down. It just so happened that it was up that time in the video. I'll post some ball gears later after dinner.

Howard Sterndrive said:
probably a good used upper gearcase for a 1982-1985 400 series outdrive, and a factory service manual

remove the drive, drain fluids from upper and lower, see what runs out. disassemble and replace/repair as necessary
the fact that it isn't trying to steer hard says upper is the issue and not the lower, but the lower could be junk too, but that's not very scientific...need to disassemble and check parts over.

I'd pressure test the cooling system of the engine before doing anything.

Have you cranked your head upside down in under the manifold to see if it or the block is cracked? looks like a tricky bilge to see in... mirror maybe

I've gotten my head up under there the best I can. I haven't seen anything that stands out as a crack. Are you thinking that is an issue and not the drive?

pmpmstrb · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

This is obviously the drive side ball gear. I'll have to get my brother to send me the engine side tomorrow. The engine side is no where close to this bad. It just has a few scuffs on it. This one is in really bad shape.

Howard Sterndrive · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

pmpmstrb said:
I've gotten my head up under there the best I can. I haven't seen anything that stands out as a crack. Are you thinking that is an issue and not the drive?

no, just thinking you shouldn't put hundreds or thousands of dollars into a boat with a worthless engine.
the sterndrive has failed - you should have no question about that at this point

Howard Sterndrive · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

pmpmstrb said:
I've gotten my head up under there the best I can. I haven't seen anything that stands out as a crack. Are you thinking that is an issue and not the drive?

no, just thinking you shouldn't put hundreds or thousands of dollars into a boat with a worthless engine.
the sterndrive has failed - you should have no question about that at this point

pmpmstrb · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

I plan on taking the upper apart to some degree, but if the problem isn't obvious I won't know what to look for. I'm not a mechanical idiot, just new to boats and especially outdrives. So what would you do in a case like this? Would you bother with trying to rebuild it (if the issue isn't obvious)? Or would you just try and find a running unit like this one here and just be done with it?

Howard Sterndrive · Sep 24, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

I suspect the problem will be pretty obvious... drain the fluids - if you have silver slurry, water, or nothing coming out of either the upper or lower, you'll have a better idea of the issue.

pmpmstrb · Sep 25, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

So let me ask you a question before letting you know my findings. Should gear oil pour out when you dismantle the upper and lower sections? Because I pulled all the oil plugs and nothing came out, so I started disassembly. I couldn't find a drop of oil anywhere in the system. So I'm 98% sure the cause is from lack of oil. Now the problem pretty much jumped out at me once I managed to get the shaft out of the upper assembly, boy was that a *****. Can you spot it?

I don't think I can rebuild the upper because I think the other half of the bearing has welded itself to the casing. I'm not sure I want to get a good upper and use my lower because if the system was void of oil, who knows what the lower is hiding. So what would you do in a case like this? There is maybe a spits worth of oil/grease in the lower where the upper shaft goes into.

southkogs · Sep 25, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

Spend a day or two looking through Craigslist Ads for a "donor" boat. I had a similar situation at the beginning of the year, and didn't feel quite qualified to do a rebuild on a upper gear case. I found a working stern drive (dead on match to what I already have) for under $500. I kept my old drive and have started a project of doing a rebuild on a secondary sterndrive to have around for the "inevitable day."

Just saying that I think you've got quite the problem with your drive, and it's probably more cost effective to look for a cheap working drive in need of a boat.

pmpmstrb · Sep 26, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

Already in the process of doing just that. I just wanted to know what the "experts" thought. Thanks.

Howard Sterndrive · Sep 26, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

pmpmstrb said:
So what would you do in a case like this?

I'd pressure test the cooling system. Then run the engine on the hose for about 90 minutes. If I found the block cracked, I'd push the rig to the curb with a free boat sign on it.
If the engine checks out, I'd look for a parts boat alright, but it would be a Mercruiser 3.0 powered boat with a broken engine. Then I'd pull the good 3.0 out of that rig and give the rest away.

pmpmstrb · Sep 26, 2011

Re: 3.0 OMC runs for 30 seconds, once a day

I currently have a 982740 model outdrive. Can I replace it with a model 981871? It is a 1980 cable shift and appears to be the same visually from what I can tell from the pictures. Will it work?

3.0 OMC runs for 30 seconds, once a day

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