OILFUL EXPERIENCE?
Regular problem finder Ed Hamley has reacted to the warmer weather by digging out his Norton Commando after a twoyear layup – but the joys of spring were dampened by finding that the kickstart is not turning the engine over.
“Zero compression!” he says. “Like when the splines wear out and the crank lever just slips down. In the old days a lash-up merchant like me would wrap bits of tin can round and bash the pedal back on! But the splines are fine!”
The most likely explanation I can think of is that the engine has wet-sumped and filled the crankcase with oil. Nortons have gear-type oil pumps which resist rather than prevent oil flowing backwards when the engine is stationary. If the oil level has raised above the crankshaft, oil could overflow into the clutch housing causing the clutch to start slipping. Meanwhile, having a sumpful of oil makes the engine much harder to turn over, partly due to oil drag and also because the oil creates a sort of crankcase compression against the pressure of the descending pistons. This will increase the likelihood of clutch slip – but might also make the kickstart splines slip where they didn’t before – it’s easy to tell, as the pedal won’t come back up as far as usual.
I advised Ed to drain the sump – and also the primary chaincase – and see how much oil comes out. If it’s overfull, the oil will gradually drain off the clutch – especially if Ed can get the bike started. If the splines have chosen to slip, tightening the bolt may help, but I’d remove the pedal for a look. If the pedal’s damaged, I’d replace it before the shaft suffers – or it’ll be back to the beer can!