912is High Coolant Temp - Fan?

Another thought was doing my taxi on Lane A only.   Lane B off should cause the engine to run in full rich; in theory will cool the engine more?

When I get to the run up get both lanes on for takeoff.

Well, that explains why you can not point into the wind. Thanks!

As Glen stated, this is more of an Airframe problem than an engine problem.

What Aircraft Model are we talking about???

Shawn Britton wrote:

Am I better have a 50/50 mix with water or not?

if there is a mix and it still overheats / boils that’s a big problem.

if it’s concentrate then I have a higher boil point.

right?

50/50 is recommended for the best heat transfer capability.

Not quite right.

  Water is the best fluid for heat transfer. However pure water causes corrosion problems and it can freeze and crack the engine. The temp increase in boiling point is mainly to do with the pressure increase. Most coolant systems recommend a 50/50 mix of water and coolant.

Coolant is normally just glycol and a few corrosion inhibitors it is primarily to stop freezing, not boiling.

There are stupendous claims from some coolant companies and I have probably just started an argument....

But I would suggest a good quality coolant brand and follow their dilution recommendations ....more is NOT always better.

Glenn is right about heat transfer and the Rotax Install manual section  75-00-00 pages 5 and 6 recommendation is a 50/50 mix as the best trade off between heat transfer and freezing and corrosion protection. My distributor sells Castrol anti freeze concentrate and also told me to use distilled water (eg supermarket distilled water for steam irons) as the mixer to avoid possible contamination. Rotax prohibits the use of water free long life coolants.

I think your quickest and cheapest action would be to change the coolant to be sure of the mix before anymore troubleshooting.

My CH750 temp sits on 100C at idle on a 30C day. It has also been suggested somewhere, (I can’t ffind the reference just now) that if the temperature climbs you should INCREASE idle speed to provide more cooling.