Continued thanks AVB and Norm,
I'm just the kind of guy to not let go of this problem until proven irreparable. Hence I'm prepared to entertain the idea of a repair, particularly as I can access lathes and operators at a reasonable cost and sympathetic to repairing rather than throwing out. Having said that, we are nearing the end of this Briggs adventure.
I haven't fully checked out the governor gear unit but understand that there are two parts to the shaft, allowing sliding to occur, effecting a change in position of the pivoting counterweights.
I have refitted the governor gear unit in top case to assess hole enlarging. It is certainly loose, sliding in and out freely, in fact with no resistance. Having said that, with the shaft fully inserted the play at the end of the shaft (bottom of shaft protruding below gear) is less than 2mm I would have thought. That would equate to less than 1mm (approx) of play at the opening of the hole.
Would knurling have a chance of picking up 0.5mm all around the shaft?
Would the gear apparatus need to be taken apart (I suppose counterweight pins would need to be ground off) for any machining to be done?
If and when the enlarged hole is made uniform by drilling out, I'm wondering what sort of tolerances need to be thought about when considering gear engagement. I would hope that it might be possible to drill out carefully, with the new hole being centred well enough for those tolerances to be at least not an immediate problem. Tight gears would obviously be a problem. Is suppose this strikes at the heart of whether or not that part of any attempted repair can happen without further stripping of the motor. That would be it for me.
As always, thank you for your advice and opinions. I have learnt a lot, and at least tried to avoid being part of the throw away society in which I live. Sharing knowledge and experience online is a great thing. I hope this thread can be of value to others.
