Re: 72 Commando Stator

There should never be contact between the rotor and stator. Ideally there should be a clearance of 8 to 10 thou all the way round the stator. Yours looks like it has been touching and consequently damaged from overheating.

One thing people often don't realise is that you need to check the clearance with the central outer chaincase nut fitted and tightened using a spacer to simulate the cover being on. That's how it will be when you're riding it. There are shims behind the inner chaincase on the central stud to ensure that when the front of the inner chaincase is mounted on the crankcases tightening the outer cover doesn't distort it. Sometimes, if the shims aren't correct, tightening the outer cover does distort the chaincase and you lose your carefully adjusted clearance on the stator.

Ian

Dear mathew,

I've seen worse and they worked, when stator coils go to earth they generate lots of heat and outer coating chars black and powdery,

If you have a commando then you also need a multimeter!

But to test charge circuit you need to get engine running first as alternator has permenant magnets you can easily test output voltage with a headlamp bulb. If no output then check leads where they enter stator, they are well known for snapping or primary chain eating them. If broken you will need to carve into insulation surrounding coils till you get to good wire to solder to.

But engine needs to run before buying parts you might not need. My first suspect on a non charging commando would be rectifier (assuming you don't have a short to frame) If it is one of the original lucas multiplate jobs bin it in favour of one of the cube type they are only a fiver or less on a well known auction site.

Good luck with your investigations

Martin

Words of wisdom from Martin are pretty close to correct, but looking at the condition of your rotor as well as the stator I would recommend that you replace both very soon. Do remember that the bike can be got to run from the battery, and the lights will work ie everything will work except battery charging if you have a failed stator and/or rectifier.

Full test of the stator can be found on my web site A O Services.co.uk and you might note that I sell rectifiers. Don't forget the 8 thou gap and inner chain case alignment when you refit them.