Just thought I would share this with you all. It might be useful information for someone. I had an ongoing problem with plugs fouling. No matter what I did the plugs were always sooty. A bike that has always been reliable started to become an erratic starter, and a snap throttle opening would cause it to pop and bang. Sometimes it would spit back through the card as well. Quite by chance I discovered that the tank lining was breaking down due to ethanol. The tank has now been relined with ethanol proof tank liner. I also stripped the carburettor and found that the idle circuit was full of muck and debris. I had checked and cleaned the jets several times, and they always seemed to be clear but there was little if any improvement after doing this. Anyway, I got the tank back from the guy that put the new liner in and I stripped the carb completely and gave it a good blast through with brake cleaner. This was followed by clean a further clean up in my cheapo Aldi ultrasonic cleaning tank (IMS and distilled water). What a result! The bike is back to reliable starting. One or two kicks hot or cold (first kick mostly) and it pulls like a train. It revs freely and smoothly, and idles reliably. In fact it has never run so well. And the plugs? A beautiful tan colour they do not even get sooty after idling.It has been running like this for a few weeks now. I am one happy bunney.
John