Small Engines (Lawn Mowers, etc.): 20hp engine rebuild, exhaust stroke, cam shaft

Question
I am rebuilding a 20 hp twin cyclinder B & S engine where I replaced a broken connecting rod and oil sump. I did not take note of where the timing mark for the crank and cam should be. Does Briggs offset the timing mark. The engine turns terrible hard even without the plugs

Thanks  

Answer
I haven't ever read where they offset the timing marks.  The only time I found them offset was during a factory course I attended...this was a lesson and not a production engine.

Is the engine completely back together?  If it is, then you might want to start taking it apart, checking rotation as each part comes off.  I have never found a bent cam shaft, but it's possible.

You can also follow the engine strokes to check the timing...this was the lesson they taught us.  Just start with the intake stroke and follow it through the exhaust stroke.

Let me know what you find.
Eric