115hp Johnson no spark on 3 of 4 cylinders

AGrau

Recruit
Joined
May 25, 2009
Messages
1
Looking for some help please. Purchased a 1975 Johnson 115 hp outboard motor (model #115ESL75E) and boat. Previous owner had it sitting for 3+ years with gas in it. I have overhauled both carbs and thought I was ready to go. Come to find out, what I thought was good spark is only good spark in the #1 sparkplug; 2, 3 & 4 have no spark. Replaced spark plugs, wires look ok and grounds look good. I tested the kill switch. Switch is open in ?normal ? running position? and connects or closes a circuit in the ?tripped or fallout? position. I am pretty good with mechanical and OK with electrical things (i.e., I know how to use a volt and ohm meter) I have the manual but don?t have a neon tester (I don?t even know what that is) and at this point am kind of at a loss as to what to do next other than take it to a marine shop ? any help would be greatly appreciated.
 

sjenson1

Cadet
Joined
May 13, 2009
Messages
10
Re: 115hp Johnson no spark on 3 of 4 cylinders

I just got a '72 125 hp and had no spark on 1 of the four cylinders. I ended up having to pull the flyweel and sand the contacts on the distributor.....and I reset the gap on the optical sensor. Really easy to do. I now have spark on all cylinders, but still weak on #3. Pretty sure i'm gonna need a new distributor, but maybe it will work for you.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: 115hp Johnson no spark on 3 of 4 cylinders

The motor requires a fully charged, powerful bettery to fire the ignition. The RPM must reach 300 to work.

Test for spark with all plugs out, gap set at 3/8 minimum; if you see fire, you are probably not turning fastr enough under load with the plugs in.
 

MikDee

Banned
Joined
Jun 6, 2007
Messages
4,745
Re: 115hp Johnson no spark on 3 of 4 cylinders

I just got a '72 125 hp and had no spark on 1 of the four cylinders. I ended up having to pull the flyweel and sand the contacts on the distributor.....and I reset the gap on the optical sensor. Really easy to do. I now have spark on all cylinders, but still weak on #3. Pretty sure i'm gonna need a new distributor, but maybe it will work for you.

Been there, Done that! ;)
 
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