Thanks all
If you have time to read the many pages under the heading Comet Smoking after
Rebore as specified above - ignoring the bits about reaming oil pumps and bike stands which have nothing to do with the topic - you will see that the oil hole is correctly drilled on my Comet, but in fact I blanked it off many years ago and it did not change the smokiness at all. It is OK to blank it with a disc in the timing cover on a Comet but not on a twin because the cam would be left unlubricated.
Most owners, including some of those who race do not use the cylinder feed holes and have no problems when using modern oils.
Other suggestions include- oil pooling round the inlet valve guide, worn valve guides, non-circular piston rings, oil pump not scavenging, blocked return pipe to the oil tank causing over lubrication to the rockers, mistimed or blocked breather, glazed bore caused by running in too slowly, porous head allowing oil into the inlet tract etc.
I have checked most of these possible causes of smoking exhaust with the exception of the porous head which if damaged could be fixed with impregnation of resin in a vacuum.
When I have done around 1000 miles or so in a couple of weeks to allow things to settle down I will see if the oil consumption is reasonable - say around 300 miles per pint, and if so carry on as I have been, using a bit of oil for the last 59 years!!!
Matty
If you have time to read the many pages under the heading Comet Smoking after
Rebore as specified above - ignoring the bits about reaming oil pumps and bike stands which have nothing to do with the topic - you will see that the oil hole is correctly drilled on my Comet, but in fact I blanked it off many years ago and it did not change the smokiness at all. It is OK to blank it with a disc in the timing cover on a Comet but not on a twin because the cam would be left unlubricated.
Most owners, including some of those who race do not use the cylinder feed holes and have no problems when using modern oils.
Other suggestions include- oil pooling round the inlet valve guide, worn valve guides, non-circular piston rings, oil pump not scavenging, blocked return pipe to the oil tank causing over lubrication to the rockers, mistimed or blocked breather, glazed bore caused by running in too slowly, porous head allowing oil into the inlet tract etc.
I have checked most of these possible causes of smoking exhaust with the exception of the porous head which if damaged could be fixed with impregnation of resin in a vacuum.
When I have done around 1000 miles or so in a couple of weeks to allow things to settle down I will see if the oil consumption is reasonable - say around 300 miles per pint, and if so carry on as I have been, using a bit of oil for the last 59 years!!!
Matty