1970 Johnson 1.5 hp won't start HELP:)

Joined
Nov 14, 2019
Messages
6
my little 1970 1.5 hp Johnson won't start. It has 90 psi compression, a new coil with an ignition module (I replaced the points & condenser), new plug wire, new plug boot & clip, It has what looks to be great spark. The ground strap wire that joins the mag plate to the power head exhaust plate was broken so I replaced it too. The carb was opened and cleaned. It has the original cork float, the brass tube in the carb is clean but I did not notice a tiny hole on the side of the tube like I'm used to seeing on these carbs....I looked it over several times but can't see a side hole....tried new gas in it and put some in the carb and the cylinder. No sir it won't even cough. Doesn't make sense to me. I figured it would run like a top.

anyone have one of these and can offer some useful advice?
Cheers

Jason
 

boobie

Supreme Mariner
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Nov 5, 2009
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20,826
Is that ignition module that you installed timed right with the motor ?? How large of an open air gap will the spark jump ??
 
Joined
Nov 14, 2019
Messages
6
Gap is 0.025”
can’t adjust the timing on it like you can with a points system. It’s got a very bright crisp spark. I did notice a slight rub on the aftermarket coil to the flywheel. That might be the issue
 

tomhath

Master Chief Petty Officer
Joined
Dec 5, 2007
Messages
814
I have the Evinrude version of that motor, it's always easy to start.

What does the spark plug look like after you try to start it? It might be flooding, those old cork floats don't get along with ethanol gas.
 

JohnnyGuy

Petty Officer 2nd Class
Joined
Aug 24, 2017
Messages
195
Gap is 0.025”
can’t adjust the timing on it like you can with a points system. It’s got a very bright crisp spark. I did notice a slight rub on the aftermarket coil to the flywheel. That might be the issue

I believe boobie is asking how large of an open air gap will the spark jump (ignition spark tester device like a Lisle 50850).
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,888
Well----" great spark "---Means very little.----Does spark jump a gap of 5/16", yes or no.----That would be near the maximum voltage that the system can produce.----If you put a few gasoline drops in the cylinder then you should get some action if you truly had spark.
 
Joined
Nov 14, 2019
Messages
6
got it. come to find out the ground clip that joins the ground wire the power head exhaust plate was loose. runs great now.
 
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