Posted by Greg Coffin [64.24.135.207] on Monday, September 15, 2014 at 20:39:02 :
On Saturday the boys and I were taking the WM300 into the mountains to cut some firewood. About 15 minutes into the trip the engine started running rough and lacking power. Soon after the exhaust started making a "chuffing" sound each firing cycle. We turned around a headed back home.
I checked a few things, and pulled off the spark plug wires one at a time while the engine was running. There was no change in the engine when I pulled either #5 or #6 plug wire, though there was a VERY strong spark - enough to zap me through a 24" piece of pine! I swapped out the plugs on #5 and #6, just in case both plugs went bad at the same time. Same results.
I'm going to borrow a compression gauge from a friend this week, but I strongly believe that the head gasket is blown. Or the cam got wiped on both cylinders at the same time, but I don't think that's very likely.
Is this a common issue on 251 engines? And is there a better head gasket to use, or technique with installation?
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