Temperature Guage

Hello,

I just purchased a 1978 Ski Nautique and noticed that the temp. guage is not working. I wasn't sure on how to diagnose the problem, so I thought I would start by replacing the sending unit. However, I am having a very difficult time locating a new part.

So, my questions are:
1) Is it most likely the sending unit....or is there an easy way to test.
2) Is there a way to cross reference the sending unit to something that I may find at an auto parts store?
3) Any other suggestions as to where I could locate a new one?

I am paranoid that I am overheating the engine. I can feel water going through the manifolds, but they sure get hot to the touch! This is my first in-board so you will have to excuse my ignorance.

Thanks for any information.

Have you had it out on the water?

I've just been through this with the boat on the drive. In the end it turned out there was no stat fitted and with the constant feed of cold water from the hose and no load on the engine it just didn't get warm enough to move the needle.

After a new sender and lots of circuit testing a $10 part fixed it. At least I've got a spare sender now.

The manifolds even under regular temps will be very hot to the touch, question is whether they are to hot. Did you check to see how much water you were flowing out the exhaust. I check exhaust water flow first thing every time out. You don't want to warp the heads or burn your exhaust hose up.