Hi again guys, this time I have a question on a Kubota Self Propelled push mower. It's and older 5hp model with the single bar blade. On start up and very slow idle there is a knocking noise, i've narrowed it down to the blade boss underneath. There is a single bar blade, a plastic fan that is held in by 4 bolts and when this is removed exposes the blade boss which is roughly200mm in dianeter. This is held in by a central bolt, and behind the blade boss and over the shaft is a rather large spring, similar to a coil spring in a car, I assume its purpose is to keep tension on the blade boss. When you hold the flywheel at the top securely with one hand and then grab the circular blade boss with the other hand and move these in opposite directions there is freeplay, but the flywheel and the shaft do not move, the movement seems to be coming from the blade boss moving slightly sideways when the crankshaft is held secure. Without accurate photos it's hard to diagnose I know, but my concern is that if I remove the blade boss to investigate the spring could have that much tension on it that I may find it difficult to get in back on. I have enclosed a picture of the underneath. Maybe that free play is normal for an older one of these Kubotas, I don't know. The circular fan has roughly 5 to 6mm freeplay when turning it in a circular direction on the shaft. Thought please.
Hi - great mower with an idiosyncratic clutch mechanism to prevent damage to the engine should the blade hit a solid object at operating speed.....They all show some freeplay and will rattle! Good luck getting bits, they are a great mower, though.
