Plugs can sometimes fail suddenly. I had one go on the strimmer last weekend, had been roaring away at 3/4 throttle for ages (about 30 min non stop) and it just stopped dead. After a lot of messing around I eventually discovered that the plug was a dead short internally. It wasn't due to carbon buildup as it had been running flat out, I don't really know what suddenly killed it but a new plug fixed it.
A Boat is a hole in the water, surrounded by fibreglass, into which you throw money...
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