Oil Pressure relief Valve

Willie · Jan 22, 2015

Could any of you more experienced 650 twin owners confirm the size of the spanner needed to remove the domed oil pressure relief valve. Mine has been somewhat abused over the years. I think it is probably a 11/16 A/F. It is rather difficult to get to and I will be trying with a deep socket. Any other advice welcomed.

crispey · Jan 22, 2015

stand by I will check mine tomorrow

Willie · Jan 23, 2015

Thanks Crispey, but I owe you an apology. The Domed nut I was seeing under the engine, I now know to be the Gearbox camplate plunger, not the oil pressure relief valve.

Serves me right by dashing in rather than reading the manual.

crispey · Jan 23, 2015

Hi Willie. No worries, I had a look at mine and the spanner size is a 3/8 Whitworth. I know your bike is post 1960 when whitworths were meant to have been fazed out but seemingly a few manufacturers carried on with them, using up old stock I guess. The part as described in the parts catalogue is Bush, gear gear control camplate plunger and has a part no. of T372. If yours is so rounded off it might be an idea to get a replacement and then once its arrived use molegrips on the old one. BTW you have a nice looking bike there. Hope this helps.