Honda CBX550 motorcycle '82 model. I purchased this bike recently and it had been sitting under a cover for nine years. I cleaned the carbies (three times now), changed the plugs, spark plug leads, main battery cables and more recently the ignition switch which died dramatically. I have put in a fuel tank liner and also an inline filter as the tank had some rust and leaks in it. I have also cleaned the petcock twice and the diaphragm appears OK. It has always had the intermittent problem of being difficult to start first up. Sometimes it will start without problem, run for 30 seconds and then stop. It will then be kick over but not fire. If left for a minute or so it might fire and run for one second or so but not restart. If left half an hour it will often start first kick and run no problems. Once running and on riding the bike it is usually flawless with 63 to 65mpg. It will start first kick once fully warm and even if it has been left for a while. Honda checked it over and fixed a problem in the kill switch wiring from the switchblock. They said the pulser was fine and coils were fine. I also cleaned the contacts on the main fuse which were slightly oxidised and the same with all the contacts and earths on the coils. Sometimes after trying to start without success if you turn the ignition on and off quickly a few times there will be backfire from a discharge to the spark plugs. I don't know if this is usual or not but it appears to be some kind of electrical problem. Today it stopped after running for 20 or 30 second three consecutive times and it's now officially driving me crazy. Can you please help Thanks Davydd