Small Engines (Lawn Mowers, etc.): Engine miss and backfire, toro wheelhorse, valve clearance

Question
QUESTION: Have a Toro Wheelhorse 212H ID#32-12OE01 with engine E125V-N10964B which is a 12.5 hp Onan. Has a recent new mag coil and new carb.  It runs fine at full throttle, but when you back the throttle off it starts to miss and will backfire.  Does not want to idle either.  Any suggestions?

ANSWER: Hello Neil:

This is Usually a Sign of the Valves Requiring the Valve Clearance Being Reset or Reseating the Valves. What is the Compression? If the Compression is Below 80PSI, this can Cause the Idling Problems you Described. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. 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 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John

---------- FOLLOW-UP ----------

QUESTION: Compression is around 90. Do you know what the specs are for the valve clearance or where I would find it for this model?

Thanks again.

Answer
Hello Again Neil:

The Valve Clearance is .006in - .008in Exhaust and .004in - .006in Intake. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. 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 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John