Small Engines (Lawn Mowers, etc.): murray riding mower, double pulley, traction drive

Question
I recently bought a murray riding mower used. However I didn't get a manual, The mower drive belt(not the deck belt) came off. I have been trying to figure out all day the way the belt goes around the pullies. I know the differense between idlers and pullies but still can't figure it out. All I know is it is a murray ultra 18.5 h.p. twin/42" widebody. Any info would be greatly appreciated.  
                           Thanks
                                jim

Answer
There should be a double pulley on the engine.  The traction drive belt is almost always the top belt closest to the engine.  When the brake/clutch is depressed it should move an idler away from the belt and loosen in.  

So that said there are 2 types of idle pulleys,flat and V.  Flat run on the outside of the belt and V on the engine.  Usually the tension or idles spring pulls the idler into the belt.  Put the belt on the transmission.  Then put it on the engine pulley.  The belt will almost always go from the engine to the transmission with no idlers on that side and the idler is usually on the return side.  

Do this with the deck off.  Have someone look under the tractor and have someone depress the brake/clutch.  What moves.  What idlers are in the belt path? Remember the bet guides.  They are very important.  There is usually one on the engine.  and on each pulley.  They should be bent close enough to keep the belt on but not rub on it when engaged.   Hope this helps.