Yeah that hose into the float bowl to check the float level has been used for half a century or more by mechanics.. I've been using it for more than a half century.. haha. It's a toss up whether it's best to check for fuel flow right through the carby first, or whether it's best to check it's getting to the carby as a first step. Either way we have to go on and continue looking for good flow or blockages if there is anything not right. I always suggest to people that they do the easy things first, (even if the easy thing seems unlikely, it's best to eliminate it before going for the complex stuff). Mostly, even on the side of the track, we can pull the fuel hose off and check for fuel. It's the "simple" that people need to have in their mind when they do find themselves broken down and wondering what to do. And... for Spr or anyone else reading this that is not used to diagnosis.. when we diagnose things there are two things we need to consider, the symptoms, and the circumstances.. If someone says their car makes a rumbling noise it means nearly nothing, it's just a symptom alone, but if they say it makes a rumbling noise when they go around corners, it tells a whole lot more, and if they say it's only doing it around left hand corners, then it's getting real clear what things we should be looking at. If a bike stops running at the track, that is an entirely different scenario to a bike that has sat for a week and now won't start, or a bike that sat in a shed for ten years and now won't start. So we need to know if it manifests the problem hot, cold, after a long sit, after a long or short ride, cornering, decelerating or braking, when it's wet, at part throttle or full throttle. . As far as symptoms go, we need to look for every symptom our senses can detect, visual symptoms, sound, smell, vibration or heat, even sometimes a taste we get in our mouth from certain things (no, don't go tasting things). Every symptom, and every circumstance can help diagnose a problem, and if we look really diligently for a symptom or a circumstance and it's not there, that allows us to ascertain the problem through a process of elimination.. The symptom or condition that's not manifesting can rule some things out. That's why we need the full history Spr.. Haha.