On Mon, 21 Nov 2011 17:41:59 -0500, Bob Engelhardt
wrote:

The engine on my leaf vac wouldn't start & I diagnosed low compression.
It's a 5HP B&S. Here's a picture of the exhaust valve seat (after
lapping):
http://home.comcast.net/~bobengelhardt/ValveSeat.jpg

Does it (the seat) need to be replaced? The B&S Repair Manual says that
after replacing a seat, it needs to be cut. How important is the
cutting? I'm not about to buy a cutter & I'll take the engine to a
repairman instead.

Thanks,
Bob

If you cut the valve seat or even just lap it in you reduce the valve
clearance. The end of the valve stem then needs to be ground off,
(flat and square), to get the proper valve lash. I don't remember the
spec.

The farther down you cut the valve seat the lower the compression
goes. Same goes for cutting the valve.

When you put it away for winter, a quick squirt of WD-40 in the carb
or spark plug hole is a good thing. Then slowly pull the starter rope
until you feel compression. Put it away like this, both valves are
closed and the combustuion chamber is sealed from moisture and rust.

Like the other poster said a wire brush and quick lap job shopuld get
you going for now.

Remove 333 to reply.
Randy