Originally Posted by nova_niek
Over the past years, I've been doing quite a few motorbike engine overhauls. Same problem with leaky sumps (yes even on Jap bikes). Most people try to overcome this using lots of cheapo silicone sealant or comparable stuff and doing up the sump bolts to the point where they nearly break. Doesn't always work.
Best cure against drippage is to (indeed) thoroughly clean all mating surfaces, use proper gaskets (not sure which ones are best for XE sumps) and tighten all sump bolts to the specified torque. And yes, a thin film of Würth Silikon Speciale 250 (German stuff) works a treat,
Hope this helps,
Niek