Low Speed Stall, then almost impossible to restart

Beefer

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I think I have a combination of 2 problems, but I'm not completely sure. Here's what happened today, that prompted this thread. This is not the first time I've had this happen, but I can always (usually) get it started.

A buddy came over at 6am to go fishing. Had the boat off the lift and tied up, running and warming up. I had it warming up about 15 minutes, then we shoved off. Making the u-turn in the canal, which I do at idle speed, she died. OK, no problem. Then she wouldn't start. She'd crank and crank, but not start. I may have flooded it, but I'm not sure. Dropped the anchor about 50 ft from my dock, and waited. After about 10 minutes, she started, and then died again after maybe a minute at idle speed. From that point, we couldn't get it started, tied up to my neighbor's dock, and he towed me over back to my dock.

During the wait between the 1st and 2nd stalls, the pos cable to the started solenoid got pretty warm, almost hot. Volts dropped below 12v, and it sounded like we killed the battery. Got her back on the lift, and for grins and giggles, I turned the key. Fired right up. I was out of the water, and no muffs, so I turned it right off. Lowered her back into the water, and again, fired right up. She's off right now, but before I finish this, I'm going to see if she starts right up again.

I doubt it's a fuel issue, other than me potentially flooding her, as everything in the fuel system is less then 7 months old (all filters, fuel lines, carbs cleaned, pump checked), plugs are new, plug wires new, both starter solenoids (one on the starter, and the other one) are new. Starter is old. Battery positive cable to starter solenoids are new. Positive cable between Batt 1 and Batt 2 is older, but seems ok (no visible correosion, feels pretty solid), negative cables are older, but condition seems ok as well.

It's a 1984 Merc 488R, Alpha 1, and once she's running, runs fine. It's only when in gear below about 1200rpm that I ever have an issue.

Ok, just went and started her up, she fired in 2 cranks, left the throttle in idle, and she died in about 10 seconds. Once again, I can't get her to start, either with leaving the throttle in idle, or with pumping. Once again, sounds like the battery is dying.

Any ideas? :confused:
 

mkast

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Re: Low Speed Stall, then almost impossible to restart

I might suggest posting the engine and stern drive serial numbers so someone can post a link to the Mercruiser maintenance manuals.
Follow the troubleshooting guide.
 

Beefer

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Re: Low Speed Stall, then almost impossible to restart

I might suggest posting the engine and stern drive serial numbers so someone can post a link to the Mercruiser maintenance manuals.
Follow the troubleshooting guide.

Engine serial number is 6770302. The serial for the sterndrive is worn off, but I have it somewhere.
 

Beefer

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Re: Low Speed Stall, then almost impossible to restart

Well, went through the receipts I have going back to 1991, and the sterndrive serial number has been unreadable since then.... I do know it's original to the boat, so if it helps, it's a 1984 drive
 

Don S

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Re: Low Speed Stall, then almost impossible to restart

When it dies, check for spark. Then we can isolate rather you have an ignition or fuel problem.
Also, when it dies, check the carb and see if it pump fuel out the accelerator pump holes, and check to see if the choke is opened or closed.
When the carb was rebuilt, were the well plugs in the bottom epoxied? Qjets have a problem with those leaking.

Your engine is an 84 by that serial number
Manual #3 http://www.4shared.com/document/M35B2RL4/Service_Manual_03.html
Drive http://www.4shared.com/document/zz_5pj9o/Service_Manual_06.html
 

Beefer

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Re: Low Speed Stall, then almost impossible to restart

Don't honestly know about the plugs in the carb being epoxied.

I have spark after it dies. I used a timing light, as I'm alone, but there is spark. Once it dies, it's a re-e-e-e-a-a-a-l-l-l-l-l-l-l-l-y-y-y-y-y slow crank. If I didn't know better, I'd say the batteries are dead. Could it be that one of my batteries is done? The 2 of them are wired; Pos1 to Pos2; Pos2 to starter solenoid; neg1 to block; neg2 to block. If one is no good, will this cause my 'dead battery' symptom, but then after a while the good battery 'charges' the bad, enough to get it going?
 

Don S

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Re: Low Speed Stall, then almost impossible to restart

Once it dies, it's a re-e-e-e-a-a-a-l-l-l-l-l-l-l-l-y-y-y-y-y slow crank.

No wonder it won't start. If it won't crank over at the proper speed, it won't start.
Yes, it could be your batteries, and you may have your battery switch wiring wrong. You should be able to select between either battery to use for cranking if wired properly.
 

Beefer

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Re: Low Speed Stall, then almost impossible to restart

It only cranks slowly after dying, not when I first get it going, if that makes any sense. ie., this morning, it cranked normal and fired right up, but after it died, and then I tried getting it going again, it would crank slower and slower, like the batteries were draining.

I don't have a battery switch installed yet, that's the direct wiring order that I listed.
 
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