[Dave Box]

Hello ChubbB,
The worn seal on the crankshaft will not cause low compression but it will eventually stop the engine from running. As you probably know a 2 cycle engine needs a sealed crankcase to generate the pressure to run the fuel pump and transfer fuel from the carburetor to the crankcase and then to the cylinder.
The low compression is almost certainly caused by worn piston rings and so my diagnosis is that you simply have a tired old 2PG engine. The good news is that all the parts are available and for ~ $200 you could have a handy little cart with an engine that flies. You don't need to be an engineer to do this but you should know your way around a wrench. You will have to buy a cheap two arm steering wheel puller and buy (or make) a tool to pull the clutch off. You should also be aware that as the engine is Japanese all the fittings are metric.

Dave