Small Engines (Lawn Mowers, etc.): MTD Chipper Model#246 645b352 Serail#1j306b30077-5hp B&S Engine, impeller, spacers

Question
B&S 5hp Model#135212,Type0140 o1,Code961024yb.You Said You Would Find Out What Type Shaft Is Holding The Impeller On.Weather It Is Tapered,Keyed,Or What Ever.THANKS For All Your Help.Joe

Answer
Are there any holes drilled in the center of the impeller?  Can you see any spacers behind the impeller?  Can you take a picture of the impeller?
Let me know.
Eric