well I have not had a great day, I removed carbs and gave them a good clean, in fact they were not bad only a little sediment in the bowls, gave all the jets etc a clean with carb cleaner and blew them out with compressed air. Put them back on and started up but still not right it is spitting back through the carbs, then set fire to the airbox! All four cyls are firing and all exhausts are hot (know this as I burnt my arm on one!) The only thing I did before these symptoms was adjust the valve clearances so I checked them to make sure all had some play, I couldn't do them properly as the engine was warm but all seemed to have a little free play. Any advice gladly received!