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Mz 125 Rt 2002 isn’t warming up properly!

PostPosted: Fri Jan 06, 2023 1:08 pm
by berkay_0618
Hi there! I have problem with my MuZ RT 125 2002. It isn’t warming up. It stays on 60 degrees and I think it’s because of the thermostat. So my question is can the thermostat be replaced or I need a whole housing. Can it be replaced with thermostat from other brand because there in Bulgaria I can’t find any parts for this motorcycle.

Re: Mz 125 Rt 2002 isn’t warming up properly!

PostPosted: Fri Jan 06, 2023 7:46 pm
by DAVID THOMPSON
muz.de for parts book to see where located and a cooling fluid replacement
show old one to parts guy at local shop its used in many bikes

Re: Mz 125 Rt 2002 isn’t warming up properly!

PostPosted: Sat Jan 27, 2024 5:30 pm
by nkko
Hello,
This is now a year later, and I apologize for bringing this up again.
Have you found a solution to your problem?

I am currently facing the same problem on my 2003 MZ 125 SM, which is exactly the same bike, just with different fairings.
My Coolant-Temp won’t exceed 65 Degrees Celsius, my oil never 45.

Best regards, nkko

Additional Information:
-Coolant recently changed
-Oil / Coolant level is correct
-Checked Thermostat in Boiling Pot, does open one Millimeter about 5–10 degrees earlier. Is this enough, to cause this?
-The water (Pump) flow seems ok

Re: Mz 125 Rt 2002 isn’t warming up properly!

PostPosted: Sat Jan 27, 2024 8:27 pm
by DAVID THOMPSON
drill a tiny hole in thermostat air is trapped behind it and it is not getting water to where it needs to be to open
it correct
less than .75mm
oops
this works on cars where the temp not controlled by the cap
the motor cycle caps are rated in BAR thats times 14.7 pounds

Re: Mz 125 Rt 2002 isn’t warming up properly!

PostPosted: Sun Jan 28, 2024 5:59 am
by breakwellmz
You both seem to have the opposite symptoms of a failed thermostat to my mind.
They generally fail by NOT opening, so not allowing water to the radiator making the engine overheat. Not heard of one stuck open when cold.
You can run a system without a thermostat, it just takes the engine longer to get up to temperature, but it will get there.
Not familiar with the gauges you have, how are you measuring oil and water temperatures?
Perhaps they are just over cooled, try blanking of the radiator(s)