D6 9U What Kind of Oil?

The other day gas went down into the crankcas of the pony motor. Some how it made it's way into the clutch assembly that engages and disengages the main engine. I drained out the gas/oil. Can someone tell me what kind of oil is supposed to go in there? Could someone also tell me if Delo 400 30 weight is good oil for the main engine?
Thanks

Use just regular oil in the starting engine crankcase and clutch and if the Delo is high detergent oil which I think it is then that,s good for the diesel crankcase.Never leave the gas turned on for the starting engine but shut the gas off and let it stall out by using up the gas in the carb.after the diesel starts, don,t shut the kill switch off to stop it.If it keeps running with it in the shutoff position then the shutoff valve is bad so change it.This is how gas usually gets into the crankcase is by letting the gas turned on and running the tractor.