Small Engines (Lawn Mowers, etc.): follow up ---rider mower, crankshaft pulley, pulley bolt

Question
---Eric
      I have found the information you require  my machine has a rear engine and the model number is 502.255050      I  hope you can help
         L/Cole----------------------
Followup To
Question -
Eric
    A few days ago I wrote you that my 10 hp Sears rider jumps fiercely when the clutch is let out.
 On your advise I have now inspected pulleys,idler wheel.and belt all seems to be ok.
  The same thing happens even if the blade is not engaged. Is there anything more I can do to alleviate this problem
 Any suggestion would be appreciated
    Tecumseh engine          L.Cole
   
Answer -
Is this mower a rear engine mower?

Could you please send me the mower model number?
Eric

Answer
Has the belt recently been replaced?  If not, this is the first item I would start with.  Since it is a rear engine tractor the only other item in the drive train that has a bearing is the ilder.  I would remove the idler pulley and check it throughly.

I looked at your transmission and based on past experience your transmission rarely fails.

I would replace the belt, check the idler pulley, the engine crankshaft pulley bolt and engine mounting bolts.  We have found engine bolts, crankshaft pulley bolts to loosen and cause your problem.  Also, check the transmission mounting bolts.

Let me know what your find.
Eric