These old rover mulchers have fairly big design limitations. They are as they say a Mulcher, not a wood chipper. Also blades are stupidly expensive to get a hold of. I know from experience throwing a larger branch in just stalls it and shears the flywheel key. Depending on you're intended use I would be looking for something a bit more modern. I have one for my collection but that's about it.
The early briggs 5hp had an aluminium cylinder, no liner, so with a lack of oil the piston picks up on the bore. There are still plenty of proper 5's out there, just have to find them.
