Walt Conner, are you there?
I'm a new member on GardenWEB with my 1st post a week ago with a subject "Weak Running Engine.
I read many posts regarding the 42A707 18HP.
A fellow named Walt Conner seems very close with these and other Briggs engines. I've also seen his postings on other sites. The discussions that relate to my problem talk about hard starting followed by erratic running, as if on one cylinder. Some folks point to the compression release mechanism, if indeed there is one on my machine.
What I've done:
Rebuilt the carb & 3-bolt fuel pump with a Briggs kit.
Cleaned EVERY carb passage with a .012" spring steel wire then fluid & air. New plugs, too.
Hoses are new, clean tank & fuel filter with fresh gas.
Pulled the flywheel to clean & inspect. All good.
Choke plate closes & opens fully.
I keep a clean engine, good fuel & regular oil changes, etc.
Cooling fins & shrouds are always kept clear.
At this point it starts hard, will run at an idle but won't tach up on full throttle, then dies. Choking doesn't help, only to start. This condition occurred suddenly, however, this season it did seem to be slow to rev up (about 2-3 seconds) once it started. Sounds (and smells) like it's running rich.
Still a hard start and sounds like it's running on one cylinder, however when I pull either plug wire it dies, then a loud pop. Engine will not develop enough power to engage blades or hydrostatic drive.
Today I checked valve clearances and found they are within .001" of tolerance limits. (No means of adjustment on my 42A707.) Also did a compression test with my thumb. Crude, but I believe at least 80 psi on both sides.
Hope there is a simple fix that I've overlooked.
I'd appreciate the forum's help on this one.
Particularly Walt, if the good man is still with us.