Expert: John C. Bridgers Sr. - 6/27/2007

Question
Model 28N707 Type 0173-01  Code 961107ZD
Had this lawn tractor a few years and now when starting black smoke. While cutting grass gets puffs of grey smoke.

Burns small amounts of oil.

Is it worth spending money to repair?  

Answer
Hello Andy:

What is the Cylinder Compression? The Head Gasket May be Blown Between the Valve Stems and the Compression Chamber. Turn the Idle Air Mixture Screw Clockwise 1/4 Turn. This May Cure the Black Smoke When Starting. The Grey Smoke would be from a Blown Head Gasket Between the Cylinder and the Valve Stems. When the Head Gasket Blows here it Sucks Oil From Around the Valve Stems an Into the Cylinder During Intake Stroke Causing the Grey Smoke when the Cylinder Fires. Grey Smoke is Gas with Just a Small Amount of Too Much Oil. Black Smoke is Too Much Gas and Whiteish Grey Smoke is Gas and an Excessive Amount of Oil Burning in the Cylinder on Compression Stroke. Usually the Whiteish Grey Smoke Happens when the Crankcase is Overfilled with Gas and Oil Mixed Due to the Carburetor Flooding when the Engine is Not in Use and the Crankcase Becomes Contaminated with Gas. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model Numbers 28N707-0173. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John