Saracen exhaust running HOT

[Les Fisher]

Usually there is two main reasons for a hot exhaust. One is ignition timing and the other is a plugged exhaust.

[Phil Waterman]

Hi

Agree with Les, timing and plugged exhaust. Critters once loaded the muffler on my HUP with acorns which in a very short run had the muffler glowing red.

Cheers Phil

[colin jones]

Hi Peter, you may also want to check if your model has the reverse cooling system. If it does then that would certainly make it run hot.
Colin.

[peter clemmer]

Thanks for the replies. It does not have reverse cooling so we can rule that out.
I haven't taken the muffler off to check for plugging, but I suspect that is not the problem since the exhaust pressure seems to be ok, could be wrong though.
When I get some time will try to check it out.
Peter

[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

[Hans Mulder]

If it isn't timing it could be a blockage - put a few strips of masking tape along the length of the exhaust when cool. Fire it up and watch the tape as she idles...the masking tape will start discolouring/burning first in your problem spot.

[peter clemmer]

Thanks for the temperature information. I will try the IR thermometer and the tape trick.
Let you know what happens.
Peter