1978 Mercury model 200 (20 h.p.) not starting

imabrewer

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Jun 25, 2002
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10
I have a Mercury model 200 that will not start. I had the bowl on the carbeurator fixed last year because it had a leak, the choke is working fine, and it has brand new plugs, but it will still not start. About every 20 pulls on the cable it will backfire once, but nothing happens. <br /> I cleaned up the wire posts on the spark plug solenoids (coming from the electronic ignition) because they were really corroded. I'm assuming these are solenoids? They are orange and the spark plug wires plug into them. <br /><br />I've checked my kill switch to make sure it wasn't keeping the engine from starting. There are 2 wires from the ignition going up to the magneto, and 4 wires coming from the ignition going over to the spark plug solenoids....what is the safest way to check and make sure I'm getting a good spark? Is there a way to make sure the electronic ignition is working? or does anyone have an idea why this motor is not starting? I've also tried starting fluid to no avail.<br /><br />I should also mention that my fuel primer bulb does get hard, but if I pump too much on it I get gas coming out of a small slotted hole to the upper right of the carbuerator intake. I'm guessing this is an overflow port (I hope)? <br /><br />Thanks in advance for any help :)
 

Laddies

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Sep 10, 2004
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Re: 1978 Mercury model 200 (20 h.p.) not starting

It sound like a ign, problem use a spark plug with the ground electrode cut off if you don't have a spark tester pull it over and see if you have spark, if you do try new plugs, but I don't think you will have spark---Bob
 

imabrewer

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Jun 25, 2002
Messages
10
Re: 1978 Mercury model 200 (20 h.p.) not starting

Thanks for the ideas Bob...I figured this one out finally. On a whim, I switched my spark plug cables around since it's only a 2 cylinder engine. About 4 pulls into trying it, the thing fired right up!! I think last year when the guy worked on the carbeurator, he got the ignition wires to the spark plugs on backwards. <br /><br />Both wires are the same length, and the only reason I thought to try switching them was that one wire had a piece of tape wrapped around it that looked like it was there to keep the cowling from rubbing through the wire. The wire on the upper piston didn't even come close to the cowling. So....mystery solved for now! Thanks again.
 
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