I am working on a 64 sporty that belongs to my buddy. It has no spark. The Mag looks like new inside and was built by Bomar. Points look new, spark plugs wires check good. Is it likely the Magnets are weak from sitting for 15 years.
The bike is complete and near to stock with the exception of seat and 6 inch over forks and handlebars. Its a cool old bike
Any ideas on getting the mag to light up?
After it runs time for minor restore and local rides on this classic.

T

 

I have never seen a Bomar Magneto, I would like to. I assume it must be built on the same platform as the Fairbanks. I have heard they are better.
I had some difficulty with mine in the past and I got to a point were I was questioning the magnets and talking to some old Tractor guys convinced me that recharging the magnets was the way to go...however, I was lucky enough to have and old harley guy at the dealership I support. He told me he has never seen or heard of a harley magneto needing a recharge. So, I replaced everything in the magneto without any luck...it turned out to be the insolator on the post was worn and it was grounding itself.

I have since talked to other old bikers and have been repeatedly told the charge in the magneto will out last me. I expect yours is the same and there is simply a short in it somewhere that is grounding the unit.

 

Check the points for a grounded state somewhere in the circuit. Recharging magnets is a good thing to do, but even if weak will give some sort of spark. Recharging mine changed the starting routine from a 45 minute ordeal to a couple of kicks. Morris Magneto charged my rotor for $25 - money well spent IMO.

 

Like these guys have already said, check to make sure that the primary circuit is not grounded. If the primary circuit is grounded, the magneto is completely dead. Taking the ground off of the primary makes the magneto come alive.

 

are the points 15years old..even if they look good they can be coroded,and the spring gets weak,clean or replace them and a new condensor is cheap and easy enough..if that doesnt work,there is a short or bad conection somewhere..

 

just my 2 cents worth but it is advisable to FLASH the field coils whenever wires have been removed from regulator, or after generator or battery has been removed and is reinstalled. This is done by momentarily touching a jumperwire between BAT terminal and GEN terminal on regulator,after the wires have been connected and before starting the bike . On bikes without a battery, connect negative lead from a battery to generator frame and flash positive lead to generator 'A' terminal. the momentary surge will correctly polarize the generator. I ran a 69 sporty for longer than i can remember hope this will help

 

bikes with magneto ignition will run without a working battery, regulator and generator.

All the other points are good advice though. For the cost of everything you might as well just replace internals and start fresh...the coil is the most expensive part...so just put it on a meter to check it and replace if necessary.

 

Here is page with lot's of info about magnetos

http://www.oldengine.org/members/die.../Petrolmag.htm

 

send it to joe hunt for repair JMMHO

 

I'd like to know how that works for you. I did entertain that idea in the past...but I was a little nervous about putting my mag at the mercy of the Post.

s