<HTML>I have a 1976 Garelli eureka flex and i found with that and my other mopeds venting exhaust more quickly and efficently can increase horsepower and aceleration remarkably. The easiest way to do this is to drill a small hole(s) in any restriction in the exaust tube or to remove the baffle located inside the muffler.
Warning: DO NOT drill the holes too close to the engine or it could cause reed valve and fuel line damage or cause the engine to over heat. This is NOT a good idea for older motobecanes with the aluminum head gaskets. You must also be careful not to over rev the engine as it will now have more power than it was design to have. </HTML>