Small Engines (Lawn Mowers, etc.): john deere RX73 variable drive belt adjustment, variable drive, shift lever

Question
Hello, I need to adjust the variable drive belt but can't find any adjustment. If you push and hold shift lever forward and push down hard it will go faster. I only get up to 4th speed out of 7. Can you hlp me ? I've worked on auto and any thing with a motor for 20 years bit this one has me stomped.  

Answer
 Hello Steve:

 Check the Linkage for Wear or Bent Components. Check the Mounting Bolts for the Transaxle. Check the Frame Where the Transaxle Sets for Breaks or Cracks. There is no Adjustment for the Belt. Hope this Helps. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John