Wednesday, 28 July 2010

Another bike, another problem

Apologies for not posting since I came back from holiday but there's been not much happening, I've got the post holiday blues now, mainly due to the poor weather. Since I came back there has been almost constant clouds with little sun really, the temperature has gone from an AVERAGE 35Deg C on holiday to a Scottish summer average 18 ish! No wonder we are classed as Dour Scots (Miserable) its because of the Dour weather! On the bright side the holiday trip was fantastic and the memories will keep me going at least until we go off to the Begonia rally in Belgium at the end of August.
A few days before I left on holiday I bought yet another Commando, a very nice 750 Commando from a very nice man in North Yorkshire (thanks David), of course there are always some things to sort out when you buy a Norton (normally) and this one was no exception, the right hand inlet valve was stuck wide open, actually more open than its possible to get with normal valve operation.

This is the bike about to be operated on

And this is the problem, note the spring seems coil bound!

After removing the head the valve took some force to return to its seat so I could remove it, the valve was (exepctedly) bent where it had touched the piston and was very tight to get out of the guide. Investigation showed that the guide in question (a relatively new Bronze guide) had a tight spot (possibly caused by the valve being bent) but the guide didn't have sufficient valve - guide clearance, a check of the others showed them to be OK. So it was a trip round to see Alex in his very well equipped workshop where we first reamed the guide out to slightly undersize then used a hone to carefully remove enough material to restore clearance, new valve and seal fitted so hopefully thats it! I think the sequence of events has been, valve sticks in tight guide which allowed the pushrod to jump out of the rocker ball and catch it on the side where it pushed the valve further into the cylinder, bending it and jamming it with the coil binding. Rebuild hopefully tomorrow so I'll keep you posted.

More boring than holiday pics so I'll post the best of these soon!

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