Re: Help! no spark. '72 50hp johnson
The stock stators do get pretty hot and some people recommend replacing them just for that reason. I bought my ignition parts from a couple of sources, after shopping for price. Even though I try to support my local dealer, I don't recommend buying directly from OMC/BRP because their pricing is very high, and rumour has it that the parts are rebranded aftermarket parts anyway. I did make an exception on the coils (I replaced all three of mine) because they are the OMC part and I like the way they are made. They also aren't all that expensive. Be aware, however, that while I was able to buy three of the stock OMC coils, BRP appears to be selling aftermarket coils for the older motors too, so there may not be any value in paying a higher price at the dealer.
Sierra and CDI are your best bet and there any many retailers selling their parts. Some say CDI products are better, and I recommend that you surf the net for the best price, taking reseller reputation, longevity and credit card security into account. IBoats may be a source, as well as others.
If you have two bad sensors and a bad charge coil, you are going to have to replace both units. Unfortunately, they are also the two most expensive parts in the ignition system. The only alternative that I can offer you is to replace the sensors in the old timer base, if you can find a pair that are within spec. These sensors are no longer made and the new timer bases are sealed units, so finding serviceable sensors for the old, metal timer bases is difficult.