The temperature guage on my 40hp perkins diesel engine flickers when I increase revs over 8000 rpm. This makes the temp difficult to check. Can anyone help me solve this problem?
If its steady up to the stated revs then its possibly just a vibration disturbing the sensor connection, which should be down on the engine block. Try taking the connection off and cleaning the contacts, then ensure it fits back firmly.
or praps if that doesn't work, the damping on the gauage has had it. Get the model number and hawk around for a new one? Generally, I find that they 'gines either run at correct temp, or if they don't they fly off the scale very quickly, at which point stop engine...
It needs more info, are the guages electrical or capillary?
If electric then the vast majority use a bi-metallic strip which is heated by the current which is driven from the sensor.
In this case the damping is done by the bi-metallic strip type movement.
These guages are the ones that move slowly when switched on.
The only thing that would make the needles vibrate is vibration itself.
To test the temp guage remove the lead that goes to the sender and
earth it too the block, the guage should slowly go to full scale without vibrating,
if it does this then the vibration is another source, possibly damping excessive vibration etc.
Have you ever had a british motobike? These always flickered. If they flicker around a certain point on the dial, then they are vaguly readble. So stuff it.