Small Engines (Lawn Mowers, etc.): JD L120 Black Dust on Mowing Deck, black dust, odd noises

Question
Hi John-

I have a JD L120 mower with 69 hours on the clock.  I don't know the service history since I bought it used.  After my past two mowings, I have noticed an accumulation of black dust on the mowing deck and under carriage of the tractor.  I do not notice any odd noises or behavior.  Could this be the sings of belt wear? or possible PTO Clutch going bad?  I removed the mowing deck between mowing to check pullys and spindles, all seemed fine.  The belt looks normal to me but I have nothing to compare it to.

On a side note, after I was done mowing I shut down the engine, a few minutes later started it up again and a rather large puff of blue smoke came from the exhaust.  I have never seen that before and don't think it is related.  I checked the oil (changed in spring) level and it is fine.

Thanks,
Steve  

Answer
Hello Steve:

Usually when there is a "Black Dust" like Substance on the Deck it is From a Belt Rubbing a belt Guard; Unless the Belts are Old and Dried Out. Then the Belts can Leave the "Dust" Just from Normal Operation. I Suggest you Remove the Spark Plug and then Tension the Deck Belt. Carefully Rotate the Blades and Watch the Belt. Correct Any Rubbing on the Guards you May See. Look at the Guards and Pulleys for Rubbing by the Belt. You can View a Breakdown/IPL of the Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers and Click Find. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John