Author Topic: BTH Magneto spark problem  (Read 2820 times)

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Offline alexd912

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BTH Magneto spark problem
« on: 16 Jul 2014 at 16:09 »
Hi there

So I have a strange problem with my reconditioning Magneto on my 600 OVH.

When the magneto is on the table it produces a great spark but when I fit it to the engine it will not spark??

When I move the mag way from the from the timing gear on the engine so i can spin the mag it sparks again (mag is still on top of the engine).

It appears to me that when the magneto is fully home in the engine it wont work. It makes no difference if its secured with bolts or not.

The magnet did work before reconditioning and the only other change is the advance/retard housing has been changed.

Best regards

Alex



Best regards
Alex
1930 Douglas G31

Offline eddie

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Re: BTH Magneto spark problem
« Reply #1 on: 16 Jul 2014 at 17:31 »
Alex,
        Which magneto is it that you are having problems with - is it the magneto in the top photo or the one in the other two?
 If it is the one in the second photo, and that is photographed on the engine, then I would guess that it is timed too far advanced if the arrow on the flywheel denotes TDC. From memory, the spark should be timed about 36 degrees before TDC. The easiest way to find this figure is to mark the flywheel for TDC, then put another mark ahead of this by a distance one tenth of the circumference of the flywheel. With this mark lined up to the reference point on the engine, set the advance/retard to the slack wire position, then time the mag up so that the points are just about to open. When they are over advanced, OHV Dougs can be a sod to get started, and if the engine is trying to kick back, the crank may be turning too slow to get a good spark.
  Regards,
               Eddie.

Offline desmobikes

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Re: BTH Magneto spark problem
« Reply #2 on: 16 Jul 2014 at 22:29 »
Make sure when the the advance housing was changed that the correct handed points were installed, the points may be running backwards when connected.

Offline alexd912

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Re: BTH Magneto spark problem
« Reply #3 on: 21 Jul 2014 at 21:29 »
Thanks everyone,

Tomorrow I will get back to this and try and get my dougie running..

I very much appreciate all the help everyone is giving me.

Ill keep you posted.

Alex
Best regards
Alex
1930 Douglas G31

 

motorcycle