Tornado
VIP MEMBER
- Joined
- Dec 5, 2017
- Messages
- 4,956

Because you "drained the sump of a normal oil tank’s worth of oil, " means you were cranking the engine, with all the pressure the descending pistons create from non-compressible oil where there normally would be air. That pressure reaches the crankseal and could have forced oil into primary. Either by damaging the seal or just seeping past it.How did you come to the assumption that I’d over pressurised the sump etc. that you’ve just mentioned?
if you read all of the words, you will see I said I came back to a small oil deposit ie perhaps 3cc/4cc under the bike, then I drained the sump of a normal oil tank’s worth of oil, then I removed the chain-case and wiped up another 3cc/4cc.
It is quite clearly engine oil, coming from the front end of the engine and black. Unlike the clear gearbox oil that I filled it with only recently, the gearbox doesn’t leak.
Perhaps in order to allay any more fears, I will put it all back together, then refill the oil tank and go for a ride. If I think the bike won’t move for any length of time then I will drain the tank and/or remove the sump bung.
How else do you explain oil in a normally dry primary after a wet sump start?
Another problem with a fully wet sumped engine, there will be no oil in the tank above the oil screen, so little to no oil feeding to pump, so no or low pressure out of pump during initial cranks. Don't like that.