TOPIC:

sharpo wrote:

After a couple of 30 mile rides with the temp guage up in the RED I have decided to leave it in the garage until I get round to looking at it properly.

I'm going to buy a new sender anyway but I wonder if the thermostat could be faulty, if the thermostat doesn't open would the coolant flow through the radiators ? the fans weren't working with the guage in the red so maybe it is just the sender, because the fans have worked before I assume the fan switch is ok and would close when the hi temperature was reached.

If it were overheating it would blow water out of the rad into the expansion bottle, so you can almost be sure its the sender telling porkies
John

if you have an Multimeter you can check the resistance of the sender

If it's ok, it should have about 850 Ohm at 20 degrees.

If the problem is your sender you may read something lower.
Let's say about 200 Ohm.

BTW what did your gauge show when you switch on ignition with cold eingine?

ciao Joachim

Fitted the new sender and it's fine now, needle straight up even after a good thrashing.

I compared the two senders, cold (15+-)they read very close to 1Kohm, I put them in boiling water and tested them as soon as they came out and they both were around 140 ohm and rising quickly.

The needle starts at the bottom when I first turn the ignition on.

Good news