Mike,
I'm not sure how much preasure is in that part of the motor, so I don't know if a silicone type sealer would be necessary.
I am sure that Rich (MOB) or Steve (SISF) could be a better source of info. My personal take, any thin couting is better then nothing, if for expansion and contraction alone.
Hold out to see if MOB or SISF see this and pine in, they know their stuff.
Good luck, and ride safe.
Greg