High CHT (260 degrees) in a Rotax 912, RV-12

by David Conrad in 912 / 914 Technical Questions 13 years ago

I am trouble shooting high CHT readings in a RV-12 installation for a friend. Dynon D-180 Instrumentation. I believe it is an indication problem and the engine is NOT overheating. The aircraft has been flown once around the pattern five separate times in a one year period. All parts are supplied by Van's. Could the CHT thermocouples be not compatiable with the Dynon? or might there be Dynon programing that is required. Might getting thermocouples from Dynon fix the problem? The carb's have been mechanically & pneumatically synchronized. DexCool coolant.
Looking for answers.

Re: High CHT (260 degrees) in a Rotax 912, RV-12

by Roger Lee » 13 years ago

Roger Lee

131 5.38k 5.44k

Hi David,

To answer your question about incompatibility the answer is yes that's possible. Did Vans supply both the Dynon and sensors?
The setup in the Dynon may be wrong, the prop pitch and rpm may cause this too. Too course a pitch will easily cause that temp. Find out what the WOT rpm is flat and level. It should be around the 5500-5600 mark and not down in the 5200 range. Check for coolant lines for kinks and oil lines. Who knows it may be an air flow problem too. The temps could be right.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Thank you said by: David Conrad

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Re: High CHT (260 degrees) in a Rotax 912, RV-12

by SSN » 2 years ago

SSN

1 2 3

Hi I have a Pipistrel SW80 with 912ULS A engines. Ever since I switched to 100LL fuel from Mogas 95, I have been. getting lower max rpm at take off. (5100 as compared to 5300 in MoGas 95). Also, my CT has been increasing rapidly while I am taxing out. Couple of occasions CT reached close to 120degree C and the max RPM dropped even further at take-off roll. I tried checking everything but the issue remains. Request if you can help identify the problem. The engine is cleared for both types of fuel.

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