High discharge temp

[paul_h]

I went to an airwell package a while back that had fried the discharge thermistor.
I fitted a replacement today and test ran it. The discharge temp was 99C, which I thought was high for a maneurop recip mt80hp4a compressor.
But what do I know, I haven't works on a recip or maneurop for ages.
Suction was 6C, LP was 360kPa, HP was 1850kPa, liquid was 39C.
Condenser air (on/off) was 28/38C) Evap air (on/off) was 19.5/11.5C. The compressor cranckcase was cool.
Any ideas for the high discharge?
I tried adding refrigerant even though I could find no leaks, sp went up to 380kPa, st down to 5C, liquid, HP still the same. Discharge temp went up to 103C, but that could have just been because it was running for longer building up the heat.
Incondensibles perhaps? The system has been running for a long time and is a package unit so factory charged though.