Onan Marquis 7000 Generator Starter Revs But No Action

The top part of the housing may have to come off I can't remember. Or the wire mesh from the bottom by the muffler. If its to hard to turn the valves may need setting so the top has to come off anyway. If its real hard to turn pull both spark plugs out and the turn it to see how hard it is if its easy to turn with the plugs out you will have to set the valves to spec. I took my gen out its to hard to work on in the trailer.