Questions? Looking for parts? Parts for sale? or just for a chat,

The WD Motorcycle forum

WD Motorcycle forum
Start a New Topic 
Author
Comment
Magneto problem.

Last weekend whilst my M20 was ticking over as I performed the opening and closing of the 5 bar gate at the rear of my property, the engine died and no amount of kicking would re-start it. So I had to push the thing back up the 50 yard gradient to my workshop.:face_with_thermometer:

On testing with different plugs, there was no spark. So I removed the mag and took it to my regular guy for scrutiny..... He had last restored it in 2006.

On his test bed it only started to spark at over about 2000 revs, and once he opened it up he discovered the culprit to be lots of oil around the armature, pickup, and earth brush.

Since there is no leak around the pinion oil seal and none inside the dynamo drive chamber.....Where the Hell has the oil come from??

I probably have oiled the adv/ret cable a couple of times with a screw type oiler but I can't believe that this amount of oil could have found its way from the cable and through the points block into the armature???? :thinking_face: Ron

email (option): ronpier@talk21.com

Re: Magneto problem.

UN-funnily enough, my new purchase Matchless G80CS also recently came to a halt after being an exemplary starter - mag clogged with grease.....but I think that was down to over-enthusiastic greasing of the drive chain case???

Re: Magneto problem.

Ron,

Perhaps the 'oil' was petrol that had dripped from a faulty petcock or carb, and evaporated to leave just an oily residue? I once had that problem with a B33 (I think it was). Amazingly there was no fire. I think the petrol dripped when the petcock was in the off position, leaking between runs rather than during use.

Just a thought.

Best wishes, Allan

email (option): allanmatchless@yahoo.com

Re: Magneto problem.

I have wondered the same thing Allan, but does evaporated petrol leave a clean looking oil residue? And still no sign of it in the dynamo drive compartment.???????

I can't remember when I ever last oiled the cable, but I will be extra careful about it in the future. Ron. Baffled!

email (option): ronpier@talk21.com

Re: Magneto problem.

If it's petrol you can smell it...Petrol contamination leading to mag failure is pretty common...Of the 500+ units that were refurbished when I offered a mag and dynamo rebuilding service it was a frequent problem...Ian

email (option): ian@wright52.plus.com

Re: Magneto problem.

After cleaning, is it working properly again, Ron ?

Nieuwe pagina 1