G'day Dave,

I like the idea of having a spare too. What did you do with the red RTV, did you pull the thermister out or just put it around the wires ?
What I'm going to do is, I've ordered the correct one for up near the oil pump but since the other is already there in the sump I will repair it using Lowell's method. I have some of that JB weld which is a two part epoxy, I thought I'd give that a try although maybe that RTV would be more resilient to temperature changes. I'll put some small bullet connectors or such on both senders so I can easily swap from one to the other. It will be interesting to see how different the temperature readings are on the two senders. I'm guessing quite a bit as I think the one next to the pump is after it's been through the cooler but before the engine and what Rotax intended when specifying operating parameters. The other is obviuosly after it's been through the engine but before cooling.
I wonder if using different products to secure the thermister and wires would give slightly different readings because of the different makeup of the individual products or whether it all ends up the same temperature anyway....