Correct amc49. Compression test is next. You don't want to pay much attention to what the books and most people say about what the compression is supposed to be. The true compression reading is dependent upon many things. Such as, amount of charge in the battery (cranking speed), throttle position, miles on bike, and other factors. In this case you are trouble shooting a problem, so the compression check needs to be looked at as a comparison. All 4 cylinders need to be fairly close to each other in the amount that the gauge reads. If one cylinder is a lot lower then the others, that is a problem. Valve not seating properly, broken ring, gaulded piston, etc. If all cylinders measure within, i'd say. 10-15 lbs of each other, look elsewhere for the problem. Main thing is to have all spark plugs out when measuring the compression to avoid having the pressure cross from one cylinder to the other in the chance of a blown head gasket between the cylinders. If the compression on all cylinders is a little lower than book specs, not to worry, if all cylinders are a lot lower then book specs, worry! All this is assuming that whoever rebuilt the carbs knew what he was doing, they are tricky.