BS 14hp drops a cylinder under load, idles great!
I have a BS 400707 14hp 2-cylinder engine on my Craftsman GT6000 44" mower. The engine starts & idles great but when you open up the throttle it misses badly. Engage the deck clutch & it misses even worse. Try to mow my back yard & it completely stops firing on the left cylinder. The right cylinder is thumping right along but the left goes dead at 50% or more throttle under a load. The spark on both cylinders at idle is strong & blue (they both lit me up around the end of the plug boot)
-Rebuilt the carburator & fuel pump. Used plenty of compressed air on everything.
-Replaced & gapped the sparkplugs to .030"
-Checked ALL the wiring, especially magneto wiring.
-Even check the keyswitch to see if it was grounding the mag (it isn't).
-Replaced intake manifold to carb gasket.
-Replaced fuel lines & fuel filter
-Drained & flushed fuel tank
-Adjusted carb per BS 400000 series manual.
I bought this mower a month ago & it missed at high speed then too. Now it won't even hardly mow because it runs on one cylinder under a load! The "dead" sparkplug is clean (little soot, wet with fuel) while the firing plug is a little bit sooty for normal. Could my valves be out of adjustment? I have zero history on this engine but it has good compression & starts easy. Please let me know what I can try to get this thing mowing again. Thanks.