Hi, would appreciate some help. Cannot get Evinrude 1974 4HP (Mod No 44B36R) to run. Have a similar 1979 motor and have proved carb and magneto by exchanging on other motor. I have good equal compression on both cylinders (105psi), I have a good spark and sometimes get an occasional fire. Plugs do not appear to get very wet. I have removed reed valves and they appear to be fine. I get the feel there is not alot of crankcase vacuum, not much 'sucking' noise from the reed valves. Don't think the top crankshaft seal has gone as its very clean under magneto, there does not appear to be a bottom seal according to the manuals I have? Don't know how to check for crankcase vacuum without opening and checking seal. Has anyone got any ideas.