A friend has a beta 38 engine and the Manual says it should run at 80 deg C. but he's never seen it above 70 deg C. Running engines cooler than optimum may cause problems in the long term ?
In general, what views are there on running engines at lower temperatures?
Assuming that the gauge is correct, the main issue is that you may use a bit more fuel at the lower temp and the engine wont run as lean as desired but 70 degrees C is still very acceptable and I suggest that you dont worry about it.