new to me 1972 Evinrude 18hp spark problem

Jhansen

Recruit
Joined
Apr 27, 2014
Messages
1
Main problem is it only runs on the lower cylinder. Can barely see weak spark if I basically hold my spark testing screwdriver to ground. Prior to this, it sheared the flywheel key about 60 seconds into my first run with it. During those 60 seconds it ran well and planed the boat. I pulled flywheel, cleaned everything, lapped flywheel to crank, torqued it back down and went to the river. Fired right up and idled fine tried to get power and it would not plane the boat. The only thing that makes sense to me is to have some of the broken woodruff key material in the points area but I cleaned those up and used a dollar bill to file the point contacts. Would like this to be reliable enough to go down river and not worrying about the return trip. Thinking coils points and condensers just to cover the whole thing unless anyone has ran into this before. Also my tilt pin broke, I replaced that with a threaded rod and double nutted it on each side. Cant see spending $50 on a new one if this sounds acceptable. Also serial number starts 18202r, from what I've gathered that makes it a 1972. Thanks for the help.
 

geoffwga1

Petty Officer 1st Class
Joined
Aug 8, 2010
Messages
394
Re: new to me 1972 Evinrude 18hp spark problem

First of all it is important that the new key be a genuine omc key and not one from the local hardware store,they are just not up to it.You need to test your spark with a proper spark tester(about $10 at the local Autozone or you can make your own with a couple of nails in a block of wood,you just bend the nails to set the gap.Your spark must jump at least a 1/4 inch gap with a nice blue zap.Also retorque your flywheel to 45-50 ft lbs or you'll shear another key.Your problem is unlikely to be from bits of key(but of course,nothing is impossible).Assuming your coils are good and not damaged ,clean thoroughly and gap your points to 0.020,make sure your HT leads are not chafing anywhere and you should be good to go.good luck,someone else may have more ideas.
 

whitejd12

Petty Officer 2nd Class
Joined
May 31, 2013
Messages
155
Re: new to me 1972 Evinrude 18hp spark problem

I have that exact same motor. 18202r = '72 Evinrude 18hp. Good luck fixing. Lots of great guys on here and great info. Google Leeroys Ramblings, great info there. I just did a complete restoration on mine, plus converted it to electric start.
 

kfa4303

Banned
Joined
Sep 17, 2010
Messages
6,094
Re: new to me 1972 Evinrude 18hp spark problem

These may help. Aside from cleaning and resetting the points, makes sure that the spark plug wires are firmly seating onto the coil post. They can sometimes wiggle free overtime, causing intermittent spark. You should be able to get any of the ignition components such as the coils, points & condensers, etc.... right here at iboats for about $25 each.

3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967 (great step-by-step igniton rebuild link for OMC "universal magnetos" which were used on virtually all models from 3hp - 35hp)

Maintaining Johnson E & FD Serie
 
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