Thanks, Okiepc.  I just bought the SRX75 Saturday.  The ad said "$175, needs some work."  Today I tinkered with it a little.  You are right --- it is the Kawasaki engine, 9hp (code FC290V-CS10).  I drained the oil.  It had lots of gasoline in it.  I figured the needle and seat failed causing that.  Can I just get a new needle and seat?  Or, do I have to get the expensive carburetor rebuild kit from JD?    Another question:  I'm puzzled why I can't see the oil level on the dipstick to come up to normal.  I put in one fresh quart, then kept adding and checking.  After two quarts were put in, the dipstick still showed only about a quarter inch.  Could the previous owner have badly damaged something by running it with gas in the oil?  

    He said it started smoking, and he turned it off immediately.  I know nothing about this mower.  :confused2:   I need an owners manual and a factory service manual --- was hoping I could download them in the form of a pdf online, but I haven't been able to find them.   ..... Found hundreds of pages of Lawn Boy data, though.  Old two cycle Lawn Boys are fantastic little machines that last a long, long time.