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2003 Ignition

kentfrmca

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I've got an 2003 CB750SC that I bought new in 2004. It's got 64,000 trouble free miles and I've been riding it almost daily since new. I've owned many bikes and have been riding continuously since 1969 and am pretty familiar with motorcycle mechanics in general. I've done all service religiously since new. A week or so ago, it decided not to fire up. It turns over fine but it just seems as if the kill switch was left in the off position. I see it employs an igniter or some call them spark boxes and was wondering if they have a habit of packing it in. Some Honda's are notorious for this, some not. What say the collective mind here?
 
Spark box good. Found out it was the ignition pulse generator. Ordered a new one. While waiting for it's delivery a fellow mech. suggested cleaning it as he had had some success doing so. I did and BINGO! All is well. Now I have a new one hanging in the spares bin. There was a bit more oil near the sensor than I thought there should be and it definitely was a bit glazed
 
The airgap may have been too wide, oil should not affect them in the least. Look at the quality of your oil, metal dust in it can do that. Glazing should have zero effect on a mag impulse sensor, the magnetism goes right through anything there not metal.
 
The airgap may have been too wide, oil should not affect them in the least. Look at the quality of your oil, metal dust in it can do that. Glazing should have zero effect on a mag impulse sensor, the magnetism goes right through anything there not metal.

You are correct of course. And I did bend it closer just a smidge. And I also di lectric greased connections to the spark box brain, freshened grounds etc. So clearly as mud I can say "I fixed it" with little certainty what actually I fixed. Sometimes Luck beats good.
 
Those impulses are typically very low volt and on automotive applications they often use shielded wires there. The pulses can be low enough to be affected by any voltage corona on them like the wires passing near a high volt source or like that, so anything you do to make signal stronger is better.
 
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