1968 6HP Johnson magneto - how does it look??

[Swell]

Here's 3 photos of the magneto from my recently bought Johnson 6HP from 1968. The coils look to be in bad shape.

I'm trying to sort out poor starting, intermittent cutting out of one cylinder (especially when warm) and lack of idle. Carburettor's been serviced and I'm in the process of fixing a sheared head bolt & replacing the head gasket. So now I'm looking at ignition and I suspect it's at fault.

Points & condensers look ok but hard to tell if they really are.

If anyone can let me know their thoughts from looking at the pics below that would be very much appreciated. I read in another post that poor coils can get worse when warm.

 

[Daviet]

Re: 1968 6HP Johnson magneto - how does it look??

Coils are junk, replace them both. The points are probably just as old, you may be able to clean and reset them, but it might not hurt to replace the points and condensers also.

 

[bktheking]

Re: 1968 6HP Johnson magneto - how does it look??

Points look good (but hard to tell since I can't see the surface of them) the coils are paperweights, put new wires on it too if they are old.

 

[Swell]

Re: 1968 6HP Johnson magneto - how does it look??

Is there any way to test the wires, points and condenser without a full ignition tester?

 

[Chinewalker]

Re: 1968 6HP Johnson magneto - how does it look??

Just replace them - cheap insurance! You can replace everything on the plate for less than $70.00 if you shop around a bit. Then it'll all be new and you shouldn't have to worry about it for years...

 

[Swell]

Re: 1968 6HP Johnson magneto - how does it look??

I get your thinking on that one! Will do.

 

[lindy46]

Re: 1968 6HP Johnson magneto - how does it look??

Points and condensers are about 20 bucks. I'd just replace them with the coils. The aggravation of having to re-pull the flywheel when you find there is a bad set of points just isn't worth the $20.

 

[Swell]

Re: 1968 6HP Johnson magneto - how does it look??

I ordered a full set of ignition parts today but the spark plug HT wires were listed as obsolete. Is there anywhere which stocks these or can the wires be made up using the correct cable type and caps?

 

[Daviet]

Re: 1968 6HP Johnson magneto - how does it look??

You can make the wires, check with your local auto parts store for SOILD core wire, usually sells by the foot.

 

[cajuncook1]

Re: 1968 6HP Johnson magneto - how does it look??

Here is a nice read about your motor....machinist does an excellent job.

http://www.sschapterpsa.com/ramblings/OMC_6hp.htm

 

[Swell]

Re: 1968 6HP Johnson magneto - how does it look??

Cheers for that - I came across that page a while back and at one point even emailed the author with a question and he was more than helpful. It's a great article and captures what it is to own and work on an old motor.

 

[Swell]

Re: 1968 6HP Johnson magneto - how does it look??

One more question - actually 3! I've ordered replacement coils but do they typically come mounted on the lamination mount? If not, is it an easy enough job to remove the old coil without damaging the lamination and also how easy to fit the new coils? ALSO....how easy is it to attach the HT wires to the coils?

 

[lindy46]

Re: 1968 6HP Johnson magneto - how does it look??

3 bolts hold the coil on. Remove old coil and bolt new coil in place. Wires just push into a pin on the side of the coil. Sometime the pin is like a small screw - just twist the wire into the pin on the coil. Check continuity.

 

[cajuncook1]

Re: 1968 6HP Johnson magneto - how does it look??

One more question - actually 3! I've ordered replacement coils but do they typically come mounted on the lamination mount? If not, is it an easy enough job to remove the old coil without damaging the lamination and also how easy to fit the new coils? ALSO....how easy is it to attach the HT wires to the coils?

Here is a link supplied by Iboats in the Johnson/Evinrude Repair section that we are in now. It is a sticky at the top of the page listed as Secret Files. (There is a bunch of really good stuff in there.)

http://forums.iboats.com/showthread.php?t=294072

Remember when you go to adjust and set the new points. Remove the spark plugs from the motor. This will make turning the crank shaft much easier and prevent accidental starting of the motor.

Also when go to gap the points, only one set of points can be set at one time. To set the other, the crank shaft has to turned clockwise (put the flywheel nut on and turn the crank with a wrench or shock wrench) until the point shoes riding along the cam open the opposite set of points (the other set of points are now closed).

Good luck and I hope you get her running soon!!

 

[EricJRW]

Re: 1968 6HP Johnson magneto - how does it look??

Well I realize it's too late, but when I had this sort of problem I was told to measure the resistance of the magneto. The range I was given was 3K to 20K ohms, and mine turned out to be 5K (2HP Suzuki). In your case, if the resistance on both was the same, I'd be tempted to call them good... But on a 68 you really can't go wrong replacing all the ignition parts.

 

[learningasIgo]

Re: 1968 6HP Johnson magneto - how does it look??

Here is a link supplied by Iboats in the Johnson/Evinrude Repair section that we are in now. It is a sticky at the top of the page listed as Secret Files. (There is a bunch of really good stuff in there.)

http://forums.iboats.com/showthread.php?t=294072

Remember when you go to adjust and set the new points. Remove the spark plugs from the motor. This will make turning the crank shaft much easier and prevent accidental starting of the motor.

Also when go to gap the points, only one set of points can be set at one time. To set the other, the crank shaft has to turned clockwise (put the flywheel nut on and turn the crank with a wrench or shock wrench) until the point shoes riding along the cam open the opposite set of points (the other set of points are now closed).

Good luck and I hope you get her running soon!!

So glad I read around a little before asking my stupid questions!!! Haha. I am trying to diagnose (I started another thread) my problem on my 1961 18 hp Johnson FD-15, and couldn't figure out why one side of the points wouldn't gap at all when I turned the screw!! Now I know why. Thanks for posting this.

(This little side note should be added to the "top secret" file on points - it will be helpful to many)

 

[Swell]

Re: 1968 6HP Johnson magneto - how does it look??

Some great feedback on this one - very much appreciated!! More than enough info to sort it all out.

I'll post again when I've fitted and tested the parts. I have other stuff to fix too e.g. a sheared cylinder head bolt, so it may be a while!