Small Engines (Lawn Mowers, etc.): how to split the crankcase on a Honda GX31, honda fg100, honda gx31

Question

Honda GX31   QUESTION: Hello - I am attempting to replace the piston rings on a Honda GX31 engine from a Honda FG100 rototiller. I have removed the engine from the tiller and have partially dismantled it but am now stuck.  I cannot open the crankcase.  I have removed the flywheel and the starter pulley. I have also removed 6 screws that hold the crankcase together, but cannot pull it apart. Please help! How do I split the crankcase? Thanks for whatever advice you can offer.
Jane

ANSWER: If you have as the crankcase bolts out you can use a dead blow hammer and gently tap on the lower case housing to see if it will start to separate.  It is probably just stuck by the dasher sealer.

Eric

---------- FOLLOW-UP ----------

QUESTION: Thanks for your reply.  Can you pinpoint exactly where on the housing to tap?  The housing is aluminum and very soft.  I don't want to do any damage by tapping in the wrong place.  
Thanks
Jane

Answer
I would start on the lower housing.  Use a dead blow hammer or a regular hammer and a brass punch.  DO NOT hit with a regular hammer or you can break the lower case.

As you tap you should be able to hear a hollowish sound.  If you hear a "thump or thug" there may still be a retainer holding the case.

Eric