My special thanks to both grumpy and Rodeobob for their inputs. I will look up the Queensland lemon laws to see what gives.
The 2 year warranty on the engine expires on 14 th May 2012. The engine model is 445877 - 0135 - B1, powering a Greenfield Model 34 Fastcut Ride On Mower. I am pretty sure that it is an Intek-badged unit.
My downloaded B&S parts list for the 445800 series engines does not indentify valve guides as separate parts. My local B&S repairer indicated to me that B&S supply new heads and valves as complete asemblies in cases like mine.
Regarding prices, I purchased the Ride On Mower new - they were listed at $7500 RRP, but I traded in so that I paid less than that in May 2010. Of that price, roughly how much would have been the engine cost - about $2000?
Anyway, onward and upward.
Regards,
mustang