We have recently started seeing coolant levels dropping for no apparent reason, after having drained engine to change coolant, as recommended every 2 years. After filling, we bled air from the cylinder head, ran and topped up, 3 times so far.
Beta 60 with hot water heater. 1500 hrs
We have the red header tank sold by Beta NC mounted about 18" above the engine, vented outboard (so that if the engine boiled, no hazard)
Engine has not gone over 90 deg C, and no visible steam. The engine exhaust temperature is 45 C
Bilge is dead dry
We start with header tank half full, but level drops to zero in an hour of battery charging. Engine temp 90C
Can the header tank discharge water in such conditions?
We confirmed that the leak was in the heat exchanger, and after testing all the tubes, determined that the problem was the new O-rings at each end, These were new, from Beta dealer a few weeks ago. 3mm dia
When inspecting the rings that failed, we realised that the inside diameter was about 2mm more than the 55mm OD of the end of the tube bundle.
The original rings supplied to us by Beta England years ago, seemed to have started life as 3mm diameter, but are of course distorted with a couple of years use
New O-rings same size leaked. We could not find 4mm rings here in Guatemala, so installed 5mm dia, (i.e.55mm ID, 65mmOD) which seem to hold
If our getting the wrong O-rings from the Beta dealer is a simple error in lifting off the shelf, then no problem beyond our frustration. However if the Beta spares list has a mistake it should be fixed
What are the correct dimensions for these O-rings?
