Coil and Solenoid

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jasperastro

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Have Johnson 85 etlr78 ,<br />Question, Solenoid...tried to replace with automotive solenoid, new from auto parts place. <br />1978 Ford 302 solenoid for car engine identical to one on boat motor. Hooked up and wont even click, have power, can cross jump and it will work, but nothing from a key start at all.<br />Any diagnoses on what might be the problem? Ground and all wires hooked up. Even tried another solenoid thought it might be bad, same result. Put old one back on and it clicks but will not work.<br />Question #2, Pulled plug wires off plugs while running motor to find possible coil problems, all but one will make the motor try to quit or act like its running erratic. Does this indicate a coil problem? When you disconnect this one wire the motor runs fine, no sputter, and continues to idle just fine.<br />Just chasing the ghost on to why i have no pick up when i try to get the motor to run into plane speed, just boggs out. <br />Cleaned fuel sytem, carbs, and pots, would the one coil be bad, and could this be the power problem?<br />Does anybody know where i could find a used coil, for this model? 85etlr78.<br />Thanks....jas... :eek:
 
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Paul Moir

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Re: Coil and Solenoid

Yeah, they're the same but different.<br />On the marine solenoid, one of the two small posts gets 12v from the keyswitch, while the other post grounds the solenoid's coil, often through a safety switch on the gear selector and/or throttle.<br />The car solenoid is grounded through the case, and the second small post (the "ignition coil" post as opposed to the "key switch" post) has no purpose on a boat.<br />Marine solenoids are also sparkproof, which keeps the gasoline explosions to a minimum.<br /><br />Problem 2 sounds like your getting no power from that cylinder. Are you getting spark? It should be strong and jump a good 1/2" gap. If you got spark, what's the compression like on that cylinder? How does it compare to the others?<br />Did you disassemble, clean, and rebuild the carbs?<br /><br />Good luck!
 
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Hooty

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Re: Coil and Solenoid

You can get a new coil for that engine at NAPA but before you replace it, swap it with another coil and see if the miss follows it.<br />How many small posts on the Ford solenoid?<br /><br />c/6<br />Hooty
 
J

jasperastro

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Re: Coil and Solenoid

That explains the solenoid problem,better to get a marine solenoid then, tried to save a little money.<br />The compession on that cylinder is 109.<br />The others are 110,115,115.<br />The 109 is on the bottom left cylinder.<br />There was spark coming off the plug, slight tapping sound, but when disconnected compleatly from the plug it did not even phase the motor.<br />While the others did make the motor start to gag when disconnected one at a time.<br />Would a new coil remedy this? <br />Thanks for your help....jas....
 
J

jasperastro

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Re: Coil and Solenoid

Solenoid has two small posts, it is identical to the one off the boat, except for the mounting bracket. This was removed prior to hooking up. <br />Ground wire off boat was mounted into boat bracket holding new solenoid to motor.<br />I did cross jump and it did engage the starter, so i did have power and ground, it just would not work off the key switch. <br />Napa carries this kind of coil?, cant find a number on it anywere to match up.<br />Thanks for your help....jas
 
S

Solittle

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Re: Coil and Solenoid

Before you jump to buy a coil you need to rule out the spark plug and the spark plug wire - by swapping with another cylinder.
 
J

jasperastro

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Re: Coil and Solenoid

I will try that in the morning. I have done everything else i can think of.<br />Compression is ok on all four cylinders, and i do have spark coming off the plug which is brand new.Perhaps the wire may be bad, i will check it, <br />Thanks alot....jas....
 
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Paul Moir

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Re: Coil and Solenoid

The coil is NAPA part number 18-5176 for your '78 engine, if that's what it turns out to be. You order them out of their Marine Parts catalog. Sometimes they don't know they have it.<br />There's four of them on your engine, so swap it around like Hooty said and see if the problem follows before you go replacing good (and $expensive$) parts.<br />Solenoid 18-5808 is the marine solenoid your looking for. But the 302 one ought to work if you connect one small lead to the "key/start" post, and the other small lead to the casing, and nothing to the "ignition/run" post. As long as it's not where gas fumes would collect.
 
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jasperastro

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Re: Coil and Solenoid

Update.....<br />Replaced solenoid, with one specified in previous reply, works great. Napa had it here in town. <br />Swapped around coil, top to bottom, bottom to top, coils are connected to same wire lead, just swapped around. This time when running the motor at idle, pulling plug wire from plug on both top and bottom, one at a time, it does not phase the engine, just keeps running ok...When i swap the coils back to there original spots, it only does this on one...the lower left coil, just like before. <br />After swapping around it seems i have the problem on both coils instead of one. When hooked up to original position its just one.<br />I have spark coming off plug to wire, i can see it and hear it. When i disconnect the wire from the other plugs the motor wants to die out. But when i disconnect it from this plug, it just keeps running. Confused about the swapping around, this made both coils bad instead of one.<br />Note the coils for this model are for a 1977, the 1978 for which the motor is tagged are not the right coil. It seems this motor was made in 1977 and tagged a 1978. <br />I have ordered a coil, will be here tuesday.<br />Will it hurt to splice into the lead wire that connects into the harness connector?<br />Two coils connected together to lead harness, would have to splice new coil into system.<br />Thanks for any help......making progress.....jas...
 
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Paul Moir

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Re: Coil and Solenoid

Just a thought Jasperato - <br />Mabey when the (bad) coil was hooked to the first spark plug, the plug got soaked by gas/oil since it wasn't firing. Then when you swapped coils, the coil on the first plug was good, but the plug was fouled, causing it not to spark?<br />How do the plugs look anyway?<br /><br />Get some heatshrink for your splices and do them up really good (solder them), and you should be good. If you really want to do a great job, put a little hot melt glue on the connecton before running the heat shrink up. When you heat the heatshrink, it'll melt the glue and make a nice watertight connection.<br />Always remember when wiring for the water - if it's not really classy, it won't work long.
 
J

jasperastro

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Nov 5, 2003
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Re: Coil and Solenoid

The plugs look real good, what i dont understand is that when i swapped the coils around and disconnected the wires from the plugs with engine running, neither had any impact on the motor, it just kept running. When i swapped it back to its original plug, only one acted as above, both with the swap, strange. <br />All the three others made the motor try to quit,when i put the coils back on the original plugs.<br />I will keep on trying, maybe the new coil will make the trip.<br />I will get a kit to fuse the wires together.<br />Is it normal to have a 78 motor with 77 parts in it?.<br />Napa had the coil for the 78 motor, and it did not look anything like the ones on this motor.<br />The 77 coil was a match as for the picture in the catalog.<br />Thanks for your help, i have vacation coming up and plan on being on the water!!!....jas....
 
J

jasperastro

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Nov 5, 2003
Messages
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Re: Coil and Solenoid

UPDATE<br />Connected new coil, have same problem. Have alot more spark off the plug now, but disconnecting the boot from the plug with engine running has no effect on the engine. Disconnecting the other three plugs one at a time does have a substantial effect on the engine running. Back to square one.<br />Power pack?...blue box on either side of motor, would this be bad? Wires of the coils lead to these boxes. Running out of options.<br />Also installed a inline fuel filter, connections are good, ball is hard no leaks..motor runs good,<br />Question....is a air bubble normal in a inline filter?, you can see it through the glass.<br />Any help on these matters is remedied through your advise...thanks...jas.....
 
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