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EGT gauge question
Posted: Thu Oct 23, 2014 9:51 pm
by alanscottj
I have finally had the probe fixed to my exhaust, got it welded. The gauge back light is connected and I have connected the wires to power the needle. The problem is that the needle just shoots straight off the scale as soon as I start the engine! The gauge I have is from McGill Motorsport. Anyone on here fitted one of these? Many thanks in advance!
Re: EGT gauge question
Posted: Tue Nov 04, 2014 10:30 pm
by alanscottj
ANYONE???
Re: EGT gauge question
Posted: Tue Nov 04, 2014 10:52 pm
by jonashford
Sensor fooked
Re: EGT gauge question
Posted: Tue Nov 04, 2014 10:55 pm
by YAMLAM
have you tried reversing the wires ? think i had this problem to start off with
Re: EGT gauge question
Posted: Thu Nov 06, 2014 9:07 am
by Rich_T
is the gauge powered from a battery, through the scooter battery or off the scooter wiring harness with no battery ?
Re: EGT gauge question
Posted: Thu Nov 06, 2014 10:51 am
by ForemanBob
Was the probe the matched probe that came with the EGT?
Re: EGT gauge question
Posted: Thu Nov 06, 2014 9:21 pm
by Monty
That gauge needs 12V DC so will not run on AC from the bike. As has been said swap the leads around If I remember mine its not red to red as would be obvious, tis the other way round, Good gauge for the price but the sensor seems prone to breaking at the pivot point on the exit of the probe. I have had the original and another one from McGill. They seem to last a season but have just fitted a right angle bent one from China via ebay for a few quid. Seems very well made and the temperature is very responsive.
Re: EGT gauge question
Posted: Fri Nov 07, 2014 12:52 am
by alanscottj
Monty wrote:That gauge needs 12V DC so will not run on AC from the bike. As has been said swap the leads around If I remember mine its not red to red as would be obvious, tis the other way round, Good gauge for the price but the sensor seems prone to breaking at the pivot point on the exit of the probe. I have had the original and another one from McGill. They seem to last a season but have just fitted a right angle bent one from China via ebay for a few quid. Seems very well made and the temperature is very responsive.
When you say reverse the wires - which ones? The wires on the sensor to the gauge or the wires from the gauge to the wiring loom for power for the needle?
Thanks everyone for the help

Re: EGT gauge question
Posted: Fri Nov 07, 2014 1:26 am
by coaster
He means the wires from the sensor but that won't be the cause. If the wires are crossed the needle will just go anti-clockwise just past zero. The voltage is tiny and is generated by the interaction of 2 dissimilar metals when they get hot. My CHT has no backlight and no other electrical connections for it to work but my EHT which sounds like yours but came from a microlight place needs a couple of DC + feeds (one through the ignition) and an earth as well as the 2 sensor wires. It won't work at all if BOTH DC feeds are connected.
I agree with Monty about the right angled probes, Mine lasted for a few thousand miles and only failed when I accidentally stretched the cable

Re: EGT gauge question
Posted: Fri Nov 21, 2014 6:09 pm
by alanscottj
Ok, swapped the wires around that power the needle and the needle now acts like a rev counter, goes up and down pretty much in line with the revs! Any thoughts chaps? Cheers
