Background: Homelite chainsaw runs, but it's not oiling the chain. The oiler seems to require pressure from the engine, which (1) pressurizes the oil reservoir and (2) operates a diaphram pump.
The pressure for these actions seems to come from a port drilled into the crankcase. From my vague knowledge of 2-cycles, I think there would sometimes be pressure there (during the exhaust stroke?) - that's why it needs reed valves?
My question is, if there is crankcase pressure, would that be affected by whether the spark plug was installed or not? When I spin the engine with a drill (plug removed), I do get some action on the pump diaphram, but not very much. I'm wondering if this is part of the problem, or just a symptom of cranking with the plug out.
Thanks, George