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Rotax 912ULS too cool


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Iam not sure if anyone else has had the "too cool" problem with their Rotax 912S temps however this has been a problem with mine as you willsee from the engine log figures below.(where there have been two pick ups for a parameter, I have averaged the reading)<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />


Alt 5500 ft


RPM 4600 MP 810 FF 19.5 LPH OAT 8C TAS 115 EGT 770C CHT 75C OIL T 76C


Alt 4500 ft


RPM 4800 MP 860 FF 22LPH OAT 11C TAS 117 EGT 776C CHT 80C OIL T 81C


RPM 4670 MP 830 FF 19.5LPH OAT 11C TAS 115 EGT 790C CHT 80C OIL T 77C


RPM 4590 MP 830 FF 20LPH OAT 10C TAS 115 EGT 786C CHT 78C OIL T 75C


Alt 2500ft


RPM 4710 MP 910 FF 21LPH OAT 8C TAS 115 EGT 809 CHT 74C OIL T 70C


My CTsw came from the factory in May 06 with 50% BASF Glysantin Protect Plus coolant & 50% water.


I have just replaced the coolant at the first 25 hour service with Evans NPG+ (as recommended by Rotax in the 912S manual) and what a difference it has made! I flushed the system twice using the Evans prep fluid (4 litres in all) and then added the Evans NPG+ at 100% as recommended.


CHT's are now sitting around 107C and OIL temp at 90C during cruise...when you compare that to what I was getting previously....the change of coolant appears to have solved the problem.


Figures after Evans NPG+ added:-


Alt 5500 ft


RPM 4540 MP 824 FF 19.5 Lph OAT 15C TAS 115 EGT 746C CHT 107C OIL T 90C


Alt 4500 ft


RPM 4500 MP 850 FF 20 LPH OAT 17C TAS 115 EGT 765C CHT 108C OIL T 85C


Regards Dave.



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