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Mystery Aliment bedevils my KLC

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Moosemeat
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Joined: Thu Oct 15, 2009 10:31 am

Mystery Aliment bedevils my KLC

Post by Moosemeat » Tue Aug 07, 2018 9:12 am

My engine has been starting and running well all season. We arrived at Clayton, and took her out for a cruise. Fifteen or twenty minutes into the ride the engine looses rpms and stops. I check the engine; no leaks, no fallen wires, no smells, and plenty gas in the bowl. I push the starter and it fires right up and we roar off, for another fifteen minutes until it conks out again. It starts again and runs (toward the dock this time) and conks again. One more start and we make it back. The next day I removed and inspected the fuel pump, with an audience, and found no problems. I started it and ran for five minutes. Came back later for an evening cruise and the battery was totally dead.

What caused this? Some say coil, some battery, some fuel filter, etc. I wish to add that my ammeter has been a little off lately, showing a slight charge even when the ignition is off. The battery is three years old. Any ideas?

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mbigpops
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Location: Eastern Massachusetts

Re: Mystery Aliment bedevils my KLC

Post by mbigpops » Tue Aug 07, 2018 11:13 am

Did you happen to see the ammeter when you were running ?
1953 CC Rocket Runabout "Rocket Man"

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Bilge Rat
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Re: Mystery Aliment bedevils my KLC

Post by Bilge Rat » Tue Aug 07, 2018 12:17 pm

Troubleshooting is always way better with an audience. Makes you want to charge admission.

If the ammeter is functioning correctly, the indication of charge even when not running suggests something is wrong. If you disconnect the battery and the meter now reads center line - no charging indication, then you have a problem to investigate. You could have a faulty generator cut-off relay (assuming you are using the original generator) and it's causing the battery to feed back into the generator when off. That would not explain the conking out when running though. You will need to measure battery voltage at the battery when not running, starting and also when running at idle and speed to see if your battery, battery cables and charging circuit are functioning correctly. There was a bad lot of imported cut-off relays and they could actually short out and cause serious problems.

Intermittent coil is always a chance for conking out and restarting later. Cheap and easy to replace for testing. I always carry 2 spares with me to save the day (been there).

Are you running at 6 volts or 12 volts?
1966 Lyman Cruisette 25 foot "Serenity Now!"
1953 Chris Craft Sportsman 22 foot "Summerwind"

Moosemeat
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Re: Mystery Aliment bedevils my KLC

Post by Moosemeat » Wed Aug 08, 2018 8:13 am

My generator is a 12 volt rebuilt unit on a three wire external regulator.

My distributor has electronic spark. I know that low voltage would stop the spark and the engine, but then why would it restart
and run a few moments later?

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Bilge Rat
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Re: Mystery Aliment bedevils my KLC

Post by Bilge Rat » Wed Aug 08, 2018 12:22 pm

The 3 wire generator (actually 2 + ground) and regulator is a marked improvement over the old cut-off relay that just connects and disconnects the battery from the generator. The regulator uses resistors and sensitive relays to gauge when to charge and although it is billed as "temperature compensated", it should not be mounted on top of the generator as it will get hot enough there to affect charging cycles.

From where I sit, it looks like you have more than one problem going on. One commonality in all this may be the quality of the ground connection from the battery to the engine block, starter, distributor and the rest of the engine running/charging circuits. A poor or corroded connection adds resistance to the circuit. The Ohms Law thing shows that if resistance is added in series to a circuit, current limiting (and therefore voltage limiting) will occur. This could easily affect your electronic ignition. You may want to replace the battery cables since that should be a relatively cheap thing to try. You should purchase factory made cables or if you have the capability, fabricate your own from at least #2 gauge copper battery cable with crimped terminals. Make sure all connections are clean and tight. The use of NOALOX which is electrical grease helps in keeping corrosion away. This is available at places like Home Depot.

You could also measure voltage between battery negative and the engine block when problems occur. If all is good, there should be 0 volts. Any resistance there will show a voltage of some value on a meter, indicating a poor connection.
1966 Lyman Cruisette 25 foot "Serenity Now!"
1953 Chris Craft Sportsman 22 foot "Summerwind"

Moosemeat
Posts: 67
Joined: Thu Oct 15, 2009 10:31 am

Re: Mystery Aliment bedevils my KLC

Post by Moosemeat » Fri Aug 10, 2018 5:17 pm

I have solved part of the mystery. In the process of replacing the fuel filter, I dumped the contents of the old filter into a coffee can. At first the gas appeared to have mixed with leftover coffee grounds, but spose tells me that she washed the can out before giving it to me. What a mess! I bought a load of crap gas somewhere. Little black and brown bits were on the bottom. I will now carry a spare fuel filter.
The battery has been on the charger since 2PM and has only reached 55% charge. Replacement seems likely.
The ammeter needle is still showing a slight charge, even though the battery is disconnected. I hesitate to open this thing, but hope to find that the needle is just stuck on a spiderweb or something like that. I need a beer.

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