MZ/MuZ Riders

Hello all. On my 96 Skorpion when ignition switch is on, the overheat warning light does not come on. Is this normal and would it light up in the event the Engine does overheat, or should it light up as you switch on the ignition just like most other vehicles for a few seconds then go out, which means it needs a new bulb ?. Thanks in advance.

if it's the same as a baghira,then it only works at high temp point only, along with the fan at the same time.think mine has only came on once in about 10 mths and as soon as i got out of the heavy rush hour all was normal again.

Hi Mishko.

In short, no. The light only illuminates when one of the overheat temperature sensor switch mounted in the radiator header tank, and on the left side, turns 'ON'.

If you want to test the warning light bulb (and the fan(s)), all you need to do is short out the 2 terminals across each switch in turn with the ignition on. This will duplicate the conditions in place when the switches turn 'ON' under normal running conditions due to heat buildup.

One switch will turn on the fans and is rated at a lower temperature than the other. The higher rated switch (the inner of the two on my Skorpion) will turn on the overheat warning light.

Thank you both very much.

the ignition does not need to be turned on for the fans. The fans are connected thru the 15amp fuse directly to the battery and are not turned on or off by the key.
The warning light is.
The two thermal switches have different temperatures: the fans turn on at 85-90º C, the warning light at 105ºC so, no, they do come on at the same time.
Both thermal switches connect to ground, the fans thru their own separate fuse. To check the fans, connect the two shoes at the switch together with a piece of wire. you will also have to check that separate fuse if they do not run. Depending on year, that fuse is in different places: early models have a glass fuse holder directly above the radiator- hard to get at - and this has in many cases "fused" together due to the heat there, since it is also directly above the exhaust headers. This is very often (almost always) the reason the fans do not work. Later models have a blade fuse under the seat for the fans. Replace this fuse with an inline blade fuse holder under the seat and new wire directly connected to ground if you have one of those models.
If the fans do work when shorted, chances are either your engine never gets too hot, or the thermal switch is a dud. Both are possible. If the warning light does work but never comes on, the it is very probable that the motor never does get too hot since it is highly improbable that both thermal switches are duds. You can check the switches by removing them and heating them while connected to a multimeter set to measure resistance (or to beep). it will go to zero (or beep) if the switch cuts on. The switches do go bad and are standard automotive units with standardized threads. Obviously you need the correct heat range and thread.
Except in hot summer city driving, the fans never run - or shouldn't. On the contrary, the Skorpion has more of a problem of not getting hot enuf.
Some people install a thermometer instead of that useless clock and a toggle switch to turn the fans on as necessary. Except in Cairo and Santa Fee, there is no reason to have two fans at all. Many also have only one fan, keeping the other as a replacement when (inevitable!) the fan goes bad. that way they last twice as long.

Bill, Thank you for all your help. The Fans do come on occasionaly in traffic, I still have to see the light come on though, I will test it using your method and see if it is indeed working.

my rt125 fan has came on 2 times in 6 1/2 years both were on very hot days...
i stopped to bs with a fellow i know and did not shut it down and set to long....
i checked how it was wired and test run it 2 or 3 times a year so i know it works
dave

My fans come on after five minutes stationary idle in Perth,
.
.

.
.
.
.
.
.
.
at 40 degrees Celsius in the shade, and there ain't some!

Hi,
Does anyone have a part number for a suitable replacement for the fan switch other than the OEM part?
The OEM part (number 9013017000) is priced at £36.89 from Grahams.
The warning light on my Skorpion came on today, but the fans did not.
I would like an alternative part number just in case the switch is faulty. I'm going to check the fuse and fans first.
Thanks,

David.

any thermo switch set at 85º C. (185ºF) with a M10x1mm thread works.

djsbriscoe wrote:The warning light on my Skorpion came on today, but the fans did not.

Hi David,

I'm a bit concerned that your warning light came on in March .......... Skorp's run pretty cold - they are well over-engineered, especially in the cooling department. I caned mine last 'summer' and the fans didn't come on - even in traffic in August.

To have an overheat warning at this time of year in the UK is a bit surprising - can I respectfully suggest you think of looking at other possibilities as well - possibly a malfunctioning temp warning switch?

Had overheat light come on twice, both times the fuse had blown,Reason? Replaced fuse,problem fixed,I always carry a complete set of spare fuses. Never had a problem with the fans, run a least a couple of times a day when in traffic and I give them a squirt of WD40 at each service.

Linegeist wrote:

djsbriscoe wrote:The warning light on my Skorpion came on today, but the fans did not.

Hi David,

I'm a bit concerned that your warning light came on in March .......... Skorp's run pretty cold - they are well over-engineered, especially in the cooling department. I caned mine last 'summer' and the fans didn't come on - even in traffic in August.

To have an overheat warning at this time of year in the UK is a bit surprising - can I respectfully suggest you think of looking at other possibilities as well - possibly a malfunctioning temp warning switch?

Hi,
It was probably because I was riding the bike around my local streets in first gear only I haven't adjusted the gear change lever so I couldn't get the toe of my left boot under the lever to change gear.
I didn't travel very far and I wasn' t going very fast as it was my first ride on the bike.
Hopefully no lasting damage done. The radiator was very hot so the warning light was probably working OK. The first thing I checked when I got back home was the coolant level, it was OK. Anyway the fans arent working. Hopefully this readiness to overheat is not a sign of a more serious problem.

David.

Hi all,
I've tested the fan circuit and the fans work OK. So it looks like the thermal switch will need to be replaced.
In order to replace this switch do I
a/ Have to drain ALL the water from the radiator or just sufficient to lower the water level below the switch mounting hole?
b/ The thread appears to have some kind of sealant on it, what kind of sealant do I apply to the threads when fitting a new switch?

Any advice welcomed.
Thanks,

David.

David,
The last post on this thread by Bill Jurgenson is another site that you can go to where he offers some great information on loctites product line. At the bottem of his last post note; cembalobill.blogspot
Regards,
Robert
PS Thanks Bill...