Maybe a Solution

Video Link: CHT Diagnostics

I'm frustrated with the COVID resurgence. Tampa seems to be in full bloom and I can only hope that it will die out once this latest resurgence is over. Sally and I have been doing some maintenance so we can be ready for students if/when the pandemic subsides.

CHT 1 Hot: I rechecked all of the obvious and still found nothing amiss. Certus volunteered a used radiator (fluid cooler) to try. I removed the old, then gave the system a bath. I used a water hose on inlets and outlets and let it flush the system completely. I lightly washed the whole engine removing any grime and ran water through the used radiator for a few minutes. The shock mounts would not come off the old radiator so I ordered some new from Amazon (here). I did a taxi test and saw some improvement. With Florida temperatures reaching triple digits I called it a day.

Early the next morning I rechecked all of my previous work, added about a cup of coolant and took her for a test flight. It turned into another record breaking hot Florida day but my results still showed a major improvement over previous attempts.

Rule: No training flights if OAT exceeds 90° F.

Next: Investigate the Oil Cooler.

Note: Maybe Sally would look good with a P51 scoop.

CHT 1 High

Video: CHT 1 Test

Cylinder Head Temperature. The Rotax engine uses a fluid to cool the four cylinder heads.

I'm still struggling with this. A suggestion from Ronin5573: "The awos said 26deg cel or about 76 deg f. Not a hot day. I would have to agree that the problem is still there. Your CHT are coming up much faster then your oil.  I don't think you plane has the coolant thermostat but that would be my first guess. Considering you just changed the coolant I would suspect maybe replacing the radiator cap on the tank.  Make sure its the 1.2 bar or 17.4 psi. Also when you remove the cap look into the tank and that first  inner lip, make sure its clean.  Sometimes you will see some black residue from the seal from the cap. If you do get some light sandpaper and remove that.  Could also be a bad spring on the cap.  I have herd that if there is a small leak,  or better way of putting it is if the cap allows air to pass then it messes up the flow of the coolant and almost stops the flow. Kind of like having air in the system.  they are about 80-to 90 bucks to replace.  Just a suggestion" ~http://www.scflier.com/topic/1362-cht-high/

All good suggestions but unfortunately all tried. Perhaps its time to replace the oil cooler or water cooler?

It really gets hot in Florida. I need to find a solution.