Since my last posts in this matter, I sent the machine in to a local authorised B&S repairer who advised me that the valve guides are worn to the point that intermittent misses are occurring on both cylinders once the engine warms up. He has contacted B&S in the USA regarding a warranty claim for remedial works and they have agreed to replace with new all defective parts.
(I might have been a little lucky in all of this as the machine is at the end of its 2 year warranty period this month.)
However, as it has done only 102 hours since new, and had a governor failure at ~ 50 hours I am wondering if I have a lemon, or maybe current B&S engines of this type are not what they are cracked up to be.
I do not know which particular alloys B&S use for their valve guides in these engines, but I do know that with air-cooled engines it is necessary to know what you are doing in this area, particularly in relation to the exhaust valves and guides which are exposed to very high temperatures. I understand that these working temperatures can range from around 600 to 700 deg C.
Funnily enough, the reason I purchased this current engine was because of the great performance I have experienced in the past with previous B&S single cylinder machines of various sizes.
Such appears to be life.
Any thoughts, anyone?
Regards,
mustang
