We have at our farm a very old Yazoo mower which has a replacement Honda engine which is itself probably about 20 years old. It quit running recently while my brother was mowing. I tried to start it but couldn’t. I verified it was getting fuel and spark and had a very vigorous compression, so I suspected the timing or valve train. Since it was an OHV, it was easy to pull the valve cover. Upon doing that I discovered that it had a bent exhaust push rod, and I am unable to press the exhaust valve open with my thumb, while I can manually open the intake. I assume something is causing the exhaust valve to stick, but I am not familiar with OHV small single-cylinder engines. My only experience in the past has been rebuilding older flat-heads. I would like to remove the cylinder head. I see 4 bolts which seem to be head bolts, but I do not see any seam where the block and head separates. Are the heads usually removable from the cylinder? I am uncertain of the model number. The following is what I was able to find stamped on the engine case: either QA** or OA** followed by GX140-92363. I would like to find a service manual or at least an exploded view of this engine. Does anyone have any suggestions? Thanks
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