[Phil Waterman]

Hi Peter

With my HUP it wasn't that the muffler was plugged it was that the little critters had loaded it with acorns. That burned like charcoal with the force draft of the engine, which still had enough oxygen for the muffler to glow merrily a couple of inches from the fuel tank. Out of the exhaust pipe came the fall smell of burning oak leaves. Shoving a hose up the tail pipe and turning on the water resulted in an explosive cloud of steam. Fire was out but the muffler was ruined with the seam split.

But back to your problem if you have a IR thermometer checking the exhaust manifold and along the pipe should show a steady drop in temperature. I'll check my engine test notes get some temperature numbers at particular RPM to compare to. I us my IR gun to check manifold port temperatures, good check for intake leaks which can cause high exhaust temps.

Cheers Phil