Hall effect sensors can do this. The good news is that they are cheap to replace if you are detecting these kinds of problems. I'm not sure how the dyna is packaged, but they could be epoxy filled, so access might be a problem. This is why i'm all for a reluctor setup which i believe the boyer may be. If i were designing it (and i may very well do so one day), it will be reluctor based. Its a hot environment under there and electronics, no matter how good, *will* have a limited lifespan regardless of component ratings. The idea here is for the manufacturer to over-engineer the design such that it can at least give the customer a useful servicable life for the product.
Just like your computer will die on you one day, so will your hall sensor, or power transistors, or your points and condensors for that matter. The question, how long is reasonable? 10,000kms is unacceptable and shows a clear lack of testing in a real world environment when perhaps new parts were introduced into that package, especially when so many units have come back. Either they got a truck load of iffy sensors, or it was just a bean-counter exercise.
I have a pamco, & if it ever does this, then it would be fairly easy to fix, so no worries there. I have cars in the past had the exact same symptoms. Works cold, then once warmed up, misfires then stalls. Happened on a 3 lane highway one day. I swap out the distributer with another and it all comes good. So its probably a $3 sensor thats gone nutter at the end of the day.
As for the points vs electronic debate, i'm not sure why people bother debating this. Both work, so its whatever tickles your fancy. A great combo is what Hondaman has done, so take a look into that as well.
I think the initial post is good. Not to discredit dyna, because many have had them for years and are running just fine, but more to let others know of what they might expect if they experience these symptoms.
