Hi, A friend asked me to look at his mower after some relatives had borrowed it-say no more. It had a broken shear pin and I repaired that. Now it starts easily but every few moments it will make a "popping" noise from the exhaust. I think it might be an exhaust valve in need of some service. I have tried another carby, cleaned out the old one and replaced diaphragm and gasket without improvement. The problem is not a major one and I tested the mower on a patch of my own lawn and it seems to go alright but to my "professional" pride it just isn't right. It is a Briggs and stratton sprinter engine on a Victa Vantage mower. Do you think the exhaust valve is the likely culprit. Any other ideas? I've attached a photo of the carby and the broken shear pin. [Linked Image]
[Linked Image]