Small Engines (Lawn Mowers, etc.): 14.5 backfire, compression release, valve clearance

Question
just rebuilt briggs 28707 14.5 ohv. now backfires at 1st cold start crank again then starts and runs fine. exhuast valve may be a little on the tight side about .006 or.007.but runs well and starts fine hot thanks for any input. oh it has antibackfire valve but didn't think it would affect at start up.

Answer
Hello Mike:

The Anti Diesel Valve will Not Effect the Engine During Start Up. The Exhaust Valve is Way to Close. Open ithe Clearance to .008in - .010in. The Backfire is Cause by the Compression Release Keeping the Exhaust Valve Open to Long During the Initial Start Up Pull. If the Valve Clearance is Too Tight the Exhaust Valve will Burn Out Also. 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

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Respectfully

John