Help! I need advice about my exhaust system

[bagpipe]

I have a Hovercraft with a Robin EC44 432cc 2 stroke twin. I am changing the exhaust system. The old one is very old. Now, if I put a exhaust pipe, with expansion chamber and racing muffler from a 250 cc Polaris ATV, am I in danger of damaging the motor?
Is there a significant difference in air flow between exhaust systems for different motor sizes? In this case my 432 cc vs a 250 cc.
Please let me know. Thanks
Andrew

[Smokin'Gun]

ur not gonna damage the motor but it will probably run like a piece of liquid cow crap running down a cornfield. Well wait i take that back if its a twin cylinder youll need 2 expansion chambers right? Its still not going to run to its full potential. If its a Y pipe into 1 expainsion chamber try a pipe from a newer 440cc snowmobile.

[badazz250]

I would ask more people about that one