# Briggs + Stratton 18 hp L Twin Valve Seat Loose



## marks57 (Jul 7, 2013)

I've got a '96 Wards Lawn Tractor (MTD) with an 18 hp B+S L twin motor that recently had a valve seat come loose. I suspect I let it overheat when it was clogged with grass clippings. Anyway it's been running on 1 cylinder so I pulled the left cylinder head and found the bottom (exhaust) valve seat had come loose and was jammed under the partially open valve. I was able to rotate the engine by hand and get the seat back into the cylinder. Nothing looked damaged and the seat and valve appeared ok. I then used the "punch / peen" method to fix the seat tight into the cylinder. Right away I noticed that the valve is not seating fully as I can rotate the valve when seated. Maybe a few thou clearance between the valve and the seat when closed.

Is there an easy way to remove the valve and set the proper clearance without tearing the motor down or removing it from the tractor?

http://s646.photobucket.com/user/mschmitz57/library/MTD Lawn Tractor?sort=3&page=1

Mark Schmitz


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## marks57 (Jul 7, 2013)

I should probably add that the right (good) cylinder reads 105 psi compression test while the left side still reads zero on the gauge, although I can feel some compression if I place my thumb over the spark plug hole.

I'll need to take some material off the valve stem to get the proper clearance.

Mark


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## Ed_GT5000 (Sep 30, 2003)

Lap the valve and see if it is putting a lap mark all the way around


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