I just purchased a new Toro Proline (not KAI) 21" Commercial mower which has been a bit of a disappointment due to the problems I have been having with it. I have used the mower only for 2 days and have been experiencing a few problems right from the 1st use: black smoke on starting and under load, carbon build up on mufler (can be seen in the pic), and low power (blade doesn't sound like it is up to speed and low self-propelled speed). Currently the mower starts but stalls when blades or self-propel is engaged. I wanted to see if anyone has any ideas what might be causing these issues so I can determine if this is an easy fix that I could do myself or if I need to take the mower back to the dealer. Thanks for any help.