Small Engines (Lawn Mowers, etc.): kohler ch18 blowing compression through the intake, blown head gasket, question pool

Question
i have a kohler ch18 that lost power but ran. found out one cylinder wasnt firing all the time. after playing around with it finally it started firing consistently. started mowing the next yard and about an hour of running great it just lost all power and died.  pulled spark plug from cylinder that was acting up earlier and it would start without the plug in off the other cylinder but with the plug in it just coughed through the muffler and carb.  proceeded to look into all things i saw on this site. checked flywheel key, it was fine. carb was a little loose took it off and cleaned it. with it off checked compression on cylinders. running cylinder 125psi, non running cylinder 115psi. but noticed every revolution air pushed back through intake from the side of the bad cylinder. i dont know what else to do to get it to stop blowing back into the carb. blow head gasket or cracked head come to mind but didnt want to go that far without a second opinion. thanks

Answer
Hello Matt:

>>Sorry for the Delay. This Question was Located in the Question Pool and I can Only Answer Questions from the Question Pool when I am Not Answering Questions here or at the Other Site I Answer Questions at.
>>It may be a Sticking or Burnt Intake Valve or Valve Seat as well as a Blown Head Gasket.
>>From your Description, I am Leaning towards a Burnt/Sticking Intake Valve or a Frozen Valve Tappet/Lifter.
>>Remove the Cylinder Head on the Cylinder with the Low Compression and Inspect the Valves and Valve Seats for Damage and the Head Gasket for being Blown between the Push Tube Galley and the Cylinder.
>>You can View a Breakdown of the Engine at this Site Addy; http://www.kohlerplus.com/login.asp (IE5 or Higher Required) and Select Enter as Guest. Now Select the Thumbnail of the Engine Catalog you Wish to View. You can Download this Service/Shop Manual (# TP-2428-C) to your PC also for Viewing at a Later Date.
>>A View of and a Description of How the Valves and Seats should Look are Shown in the Online Manual in Section 10 on page 189 of 232.
>>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. Have a Happy Holiday Season and May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 3 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. Follow Up Questions are Received Anytime. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John