Did I Find My Problem?

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bipolarnut

Cadet
Joined
Mar 26, 2008
Messages
19
I have no spark on my 1971 100hp Evinrude. I have no spark anywhere. I checked the voltage at the terminal with the key on and I get a little over 12volts. However when you engage the starter voltage drops to just a little over 10 volts. I think I remember reading on a post somewhere that this should stay at 12 volts but I can't seem to find it.

My question is: Could this be causing my no spark condition?

Thanks
 
david_r

david_r

Lieutenant Junior Grade
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Aug 11, 2008
Messages
1,118
Re: Did I Find My Problem?

have you tried another battery or a jump?

ive read these motors need to turn about 300 rpms for the ignition to work properly.
 
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bipolarnut

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Mar 26, 2008
Messages
19
Re: Did I Find My Problem?

No, I haven't tried another battery or a jump will do that in the AM. This battery cranks my 76 70hp rude just fine though
 
david_r

david_r

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Re: Did I Find My Problem?

i was just hoping that it was just a low charge in the battery.

i cant remember where i read about the 300 rpms but it stuck in my head.

ive read a lot of threads about no spark some are doosies to solve and none of them seem to be very cheap.

i hope it works for ya, goodluck!
 
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bipolarnut

Cadet
Joined
Mar 26, 2008
Messages
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Re: Did I Find My Problem?

It's not the battery. I am stumped. I saw a motor like mine that had been converted to a new type ignition but when I emailed the guy he said I had to be a mechanic to be able to do it. I also got an email from someone who converted the ignition to an auto type. Any ideas, I have done all the tests I know how to do that everyone has recommended.
 
david_r

david_r

Lieutenant Junior Grade
Joined
Aug 11, 2008
Messages
1,118
Re: Did I Find My Problem?

like i said i was hoping for something simple, but hang in there and im sure these guys will have you testing your ignition components in a systematic way. i couldnt tell you where to begin-ive been lucky and havent had any electrical probs.

good luck.
 
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cdoliver

Petty Officer 1st Class
Joined
Mar 18, 2008
Messages
211
Re: Did I Find My Problem?

check to see if your black with a yellow stripe wire in the big red plug isn't getting a ground all of the time. It should only get a ground when the key is off.
 
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cdoliver

Petty Officer 1st Class
Joined
Mar 18, 2008
Messages
211
Re: Did I Find My Problem?

I'm sorry I failed to read that it was a 1971. It sounds like you have a kill circuit problem. Find the wire that kills the ignition and problem solved (In the ones that have the red plug it's the black w/yellow). You could try unplugging that big plug and jumping the starter solinoid to see if the spark returns. If so the problem is probably the key.
 
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F_R

Supreme Mariner
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Jul 7, 2006
Messages
28,195
Re: Did I Find My Problem?

bipolarnut said:
I have no spark on my 1971 100hp Evinrude. I have no spark anywhere. I checked the voltage at the terminal with the key on and I get a little over 12volts. However when you engage the starter voltage drops to just a little over 10 volts. I think I remember reading on a post somewhere that this should stay at 12 volts but I can't seem to find it.

My question is: Could this be causing my no spark condition?

Thanks
Click to expand...

You don't say where you are reading the 12/10 volts. Anyway, yes it is normal for the voltage to drop while cranking. Around 10 probably is minimum. If you think that is the problem, crank it over with a rope and see if you have spark. The posts about 300 cranking rpm do not apply to your motor. And yes, you can start it with a rope.
 
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