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Engine runs fine then dies

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buzzard

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older gas inboard runs fine th

older gas inboard runs fine then just inexplicably dies ..no sputter just dies.easily restarts and then runs fine for as long as a week.but problem has been happening with more frequency and the last time she did not restart.when it runs it runs good but when it dies.....it's dead
 
How old is the boat? Ignition

How old is the boat? Ignition key switches act like that when they are really old. New ones are about $20. When you install the new one be sure the drain hole is pointed down. A weak coil can act like that. Coils are rarely a problem but when they don't go out completely what you are describing is a coil symtom. In old ignitions that have condensers I'd replace the condenser.
 
"have same problem with my bro

"have same problem with my brothers boat. had voltage to coil, to dist. none to plugs. changed coil,points,condenser,rotor. cap, plug wires, plugs still no spark. any suggestions"
 
mmmmm? i think my case may be

mmmmm? i think my case may be different but if you're getting spark everywhere but at plugs it would seem your problem may lie in the distributor which ain't distributin'...could there be a problem with the contact points grounding out?or dist not grounded..just grabbing at straws here... but the points cannot hit inside of dist housing
 
You might simply have water in

You might simply have water in the gas. Those marinas (and some gas stations) love to sell $3.00 a gallon water!

Jeff
 
"jeff, if the previous items d

"jeff, if the previous items don't get it, there is a possibility, if you have a wet cell battery, that there is built up sediment on the bottom intermitantly shorting out between two plates as the boat rocks."
 
"Exactly, Fastjeff. That is wh

"Exactly, Fastjeff. That is why I mentioned it as a second thought after investigating more common trouble spots."
 
"the battey is new. changed co

"the battey is new. changed coil because i wasn't any spark out secondary windings (coil wire to dist. ) after put new coil in , then found bad cap(where rotor rubs center of cap. still no spark to plugs. susspecting cap and rotor not right for application (used auto. type for boat, not good idea)my thought anyway. i suspect water in tank to,been sitting 2 plus yrs. rebuilt carb. yesterday, found alot of sediment in bowl. i think there is alot of problems,causing it not to start and run right. just trying to get some ideas."
 
Water condensation in fuel tan

Water condensation in fuel tanks is a big problem. You should have a water seperating fuel filter in line and keep it changed regularly. Keeping fuel topped off between uses will help reduce condensation.
 
"i think that sediment in carb

"i think that sediment in carb. and in filter con fump, plus water(condensation)in tank caused not to idle and get about 1/2 speed it should have. the boat is 35 yrs. old (71). it has just sat most of it's life. it does have a faily new engine and outdrive. i think i or he(brother) needs to pull tank and try to clean it or put in a new one (30 gal.). any more thoughts out there."
 
"i seem to have missed somethi

"i seem to have missed something here,i inquired about my boat that runs fine then the engine dies!NO SPUTTER Ie, not fuel related ...how did we ge from somebody's brothers boat with no spark and then an engine not running because of bad fuel??? help me out here??"
 
"Sorrrry, jeff. You're rig

"Sorrrry, jeff. You're right. Your problem does sound like an ignition problem. Getting mixed up between you and tom f."
 
"sorry fellows i should have s

"sorry fellows i should have started new thread for my problems. i do have two problems (no spark and not running right) i did change everything as dicribed above and still no spark,also trying to fix top end /idle problem. sorry"
 
"okay ,thanks that explains wh

"okay ,thanks that explains why /how we got to where we did with the various problems...back to my engine just shutting down .i am trying to avoid informing all of what changes i made since problem first occured because i'm not sure if it has been corrected.needless to say i have changed a lot of parts trying to figure out what the heck would make an engine just die. i will say dist and guts are all new including coil and ballast resistor and ign. switch but i will leave the rest up to forum members on what they think could be causing this weird phenomenon.any help appreciated"
 
yes !it has points and they ar

yes !it has points and they are young and do not come in contact with the housing inside so they aren't shorting out...during my numerous communications with mallory ignition tech. they have insisted that this is the way to go for a boat that goes offshore reckoning that points will miss before they quit entirely.. meaning you can get home by readjustment or filing them.other people i have spoken with are firm believers in electronic ignitions(if they break you better have another complete distributor setup ready.
 
Did you try another new conden

Did you try another new condenser?
I like points myself in a boat. Many people mistakenly think that electronic ignitions are bullet proof or that they get greater performance than is realistic.
 
"tom f, Do you have a points d

"tom f, Do you have a points distributor? Can you remove the fuel tank?
Continue on new thread."
 
"eddie, look in mercruiser lin

"eddie, look in mercruiser link thats where my new thread will be."
 
"eddie, i have changed the con

"eddie, i have changed the condenser.the problem happened with the old one so i putin new, it still happened so i put the old one back in.mallory has told me that i am getting too much power to the coil.but i have never "burned" up a set of points (single). the ballast resistor is supposed to knock voltage down to 11 or less. When i check the voltage coming to the purple (ign)wire with engine running it says 14+-and 12+- after resistor..tried to new alternators both pre tested so i'd have to say batteries are not fully charged. now when you remove alt.the #s are within specs..but i don't know what the heck that's got to do with shutting the down.could it be a tachometer malfunction ?or faulty ammeter gauge or connection that is making this engine just die after running fine?also i have a noise filter (newmar)connected to alternator for sound suppression for the radio who knows if it works i mean when i turn on a handheld i can hear the engine .could that be the culpprit???"
 
"Jeff, good thinking putting t

"Jeff, good thinking putting the old condenser back in. Once in a while condensers are bad, brand new right out of the box, but I guess thats not it. You did get the right coil, one that requires external ballast? How old is your battery? Check battery connections and clean connection of ground cable to engine block."
 
"Eddie thanks..i did get the p

"Eddie thanks..i did get the proper coil.. ALL mallory ignition parts ('cept the condenser).I have two deep cycle Rolls/Surrette batteries.they may have been down low late last fall but either one could spin engine strong and would charge up good after a run.my battery cables are old.but lugs look o.k. i do have a "burndy" buried beneath some tape connecting two negative cables but when i touch the main ground to the engine block (via the heat exchanger bracket 'cause that's as far as cables can comfortably reach) i get a good spark ....so, could any part of that cause the engine to suddenly die ???"
 
"Old batteries sometimes have

"Old batteries sometimes have enough sediment on the bottom to short across the bottom of the plates. Movement shifts the sedement hence a sudden short. As my esteemed colleague, Fastjeff, said "that's a stretch". I agree, but at this point I start checking out things like that. Are the battery cables marine grade? Even solid copper cables that are not marine grade can corode away in time. Good maintainace rules for cars sometimes aren't good enough for boats."
 
"i would hardly call batteries

"i would hardly call batteries that are two years of age,old .these are the most respected, longest lasting servicable marine batteries available ..i highly doubt that could be the problem especially not with both of 'em!..yes, the cables are all tinned wire .all wiring on the boat is tinned except for the engine harness,most of which is original but looks to be o.k. but i'll bet marine engine harnesses from the factory are not tinned and where would i find a harness that was..probably have to make it myself"
 
Did you briten the spot where

Did you briten the spot where the ground cable attaches to the engine block?
 
sounds like something groundin

sounds like something grounding out somewhere(wire) just a thought.
 
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