I have a Briggs and Stratton model 17AC2ACG055, 21 hp intex engine that I’m suspecting needs a camshaft. It was cranking and running great then suddenly it was hard to start. The engine would barely turn over, sometimes it would act as though the engine was locked up. I’m guessing this is due to the compression not being properly released. I am going to check the valves first but if it is the camshaft what is the part number for an oem b&s camshaft ? I’ve looked it up but seem to be coming up with several different numbers. Thanks for any help and advice.