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

That seat needs to be cut and probably you need a new valve as well.
I would take it in, have the seats done and new guides as well as new
valves.
Plus I'd have them check the bore and probably have it bored to the
first oversize possible.

Look at it this way, if you do it right it will last at least as long as
it did the first time. I have a few small engines around here
that are 50 years old+. As they turn from nice running engines into
mosquito foggers they get rebuilt back to factory spec.

Like I told one guy who brought in an old iron Kohler, As long as the
block is not broken in half the rest is reparable.
You can usually find a good crank (and some interchange up to current
numbers). Bore worn and they tell you that the pistons are no longer
available? Bore it out and sleeve it back to stock or to a common size.

--
Steve W.