717 running hot

[ozoneranger]

engine runs hot (sensor sounds) when idling but ok when running at cruise speed...would burning 93 octane or too rich a mixture cause carbon build up and clog exhaust water lines?..what is recommended oil:gas mixture and octane grade for SBT engine (717)..

[Bill O'Neal2]

That is usually caused by a worn out wear ring/bad impellor or both. It just isn't making enough water pressure a low idle speeds to push water through the motor with worn pump parts.

[ozoneranger]

after replacing a broken o-ring (head gasket) the engine ran fine...#1 piston must have been compressing hot gases into the water jacket...