Water temp drop

[Sad-Ham]

I noticed on saturday when I got back from a flight that if I switched off my left mag the needle on the water gauge dropped around 10 deg. I switched it back on and switched off the right mag , needle satyed exactly where it was. I have a blue top 582.
Anyone got any idea what could cause this?

[Morph]

Was it an instant drop, i.e. flick the switch and the needle drops or was it as a result of cooling down?

[Sad-Ham]

Instant drop...... switch mag off and it instantly drops about 10 degrees , switch mag back on and it goes back up again

[Morph]

That is definately electrical

[Duck Rogers]

Who's Morph..?

[John Boucher]

Mooooooooorph....... welcome back!

[V]

Hi Sad-Ham, as Morph says, if the drop is instant and your water temperature gauge is electrical, then the problem is electric. Water can't change temperature that quick. Often, electrical problems like this have something to do with the grounding. The mag switches ground the ignition, so that's another pointer in the same direction. As a first step I would check the gauge's connection to the ground. Second, the engine's ground.

Hope you come right.

Cheers,

V.

[Sad-Ham]

Thanks to all for the advice...... the problem was electrical. Re-grounded the guage and the problem was solved.