Ok... need some more help here.
Bearings were gone in my old Austrian VT49.
Pulled it down, put in new bearings, reassembled no prob. Ran like a top. Quickly developed a slight rattle (grind) in the air. Brought it in and got no noise out of it on the ground at WOT. Not sure about it at this point so flew again. This time, catastophic faliure.
Seems it popped a tooth off the lower timing gear. Lower end beat to a pulp but maybe salvageable.
1st question...
Did I miss some kind of clearance issue in reassembly? The timing shaft had no discernable fore/aft play or wear. The lower case half only bolts into one position sooo.... Im puzzled by this. One piece of info... the shim under the upper housing gear had worn out completely and had come out.
2nd question...
It appears the timing gears are pressed on that shaft. Since I busted one of the gears, can they be removed/replaced? Looks to me like clearance in that area might require a factory jig or some exacting tolerances.
This is a tired ole motor, however, internal inspection revealed a very satisfactory condition in general, ring, piston, shims, valve, etc were in very good condition.
Look forward to your reply!
Shane