Stihl backpack blower crankcase air leak?

I have an older(07'?) Stihl B 500 backpack blower; it wouldn't keep running after start and warm up, when I hit the throttle it would die but re-start with the same results. Brought it to a dealer who put a new ignition module, carb primer(said it was cracked) new air filter . Says the problem is the crankcase is leaking air and needs to be split and repaired with RTV. Big $ Never heard of this- any small engine mechs out there want to weigh in?

I get a strong feeling the kid doing the...

Stihl backpack blower crankcase air leak?