59' evinrude 50 hp magneto probs

gralyn

Recruit
Joined
Jul 15, 2004
Messages
3
hey <br />having problems with the spark <br />magneto has plenty of spark, with cap off will jump the jap from the post to the frame about 1 1/2"<br />cap has condinuity from spring to the carbon that rides on the rotor <br /><br />yet when i put the cap in position there is no spark can actually hold on to the lead <br /><br />i'm turning it over fast enough because got it hooked to a drill?<br />what seems to be the prob why am i unable to get the spark to the plugs?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: 59' evinrude 50 hp magneto probs

Have you tried a new lead.As you add components you increase resistance if there is a weak conductor, crack,corrision etc the spark will take the easiest route and you may not see an ark.<br />Check for traces made by a short on the rotor or cap.<br />The plug leads are screwed into the cap.Have you checked for corrosion there.
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: 59' evinrude 50 hp magneto probs

Do you have the correct rotor? The magneto rotor has a wide blade on it, and the distributor rotor used in later years electric shift motors had about a 1/4" blade. I don't have the part numbers handy, but if your rotor blade is about 1/4", you have the wrong one.<br /><br />A hairline crack or carbon trail on a rotor can cause the voltage to short to the grounded rotor shaft.
 

rwise

Captain
Joined
Jul 5, 2001
Messages
3,205
Re: 59' evinrude 50 hp magneto probs

I have seen roters short out, that would explain why you have no spark. Correct parts of course. Also (I have a '58 50 hp rude) I took the mag unit apart and found the bearings in it dry! I think it would be a good idea for you to disassemble and lub yours. I'll bet no one has done it since it was new! Made mine run much smoother, much!<br /><br />Welcome to the board!
 

gralyn

Recruit
Joined
Jul 15, 2004
Messages
3
Re: 59' evinrude 50 hp magneto probs

thanks guys<br />the problem started as i was out at full throttle it died so i thought it was fuel related so i switched tanks it restarted then went another 5 min died again did it 1 more time then died for good, every thing was working fine before,haven't replaced any parts yet any idea how much a cap and rotor would be for this ancient?
 

gralyn

Recruit
Joined
Jul 15, 2004
Messages
3
Re: 59' evinrude 50 hp magneto probs

found the prob <br /><br />RWISE you were right the rotor is shorting out to the shaft looks like a pin hole, to find it i put a piece elec tape between shaft and rotor and it actually burned through it in a couple of revolutions <br />in store for a new cap, rotor and wires ,look like the origanals
 

rwise

Captain
Joined
Jul 5, 2001
Messages
3,205
Re: 59' evinrude 50 hp magneto probs

Great, now back to fishing!
 
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