MZ/MuZ Riders

Just bought a 2002 MV 125 SM w 2500 miles on it. The motor oil has water in it. Kinda looks like creamer for your coffee. Drained it and put in some Kerosene heater fuel to clean and flush it out . Took off the radiator cap and had no visible coolant in it.
Now What?
The bike is very clean and only has mild scratches on it from boots and one rear blinker stock that is bent.
Where is the coolant pump?
How do I get to it?
Where can I order parts for it?
How do you drain the coolant system?
Is there an online owners manual and parts manual?
Any thing else I should be looking at?
Thanks for any help, Rob in Walla Walla, WA USA

Here is a spare part catalogue.

Have the same problem with a 2003 RT125. Have not gotten into it,yet.Pump access is through the right side cover and not looking forward to removing all the stuff in the way. Never encountered this problem in 10 years, and I have lots of MZ 125's. I will message you, have a repair manual.---Steve

Thanks for the repair manual Guesi. Big help. Anyone have a link to the owner's manual? thanks, Rob

So yesterday I tore into it, Basically drain water and motor oil
take clutch RH side cover off. Be careful and try not to tare clutch cover gasket. I did. RTV sealer is my friend .
Unscrew the 2 allen head screws holding pump on.
Pump pulls straight out. But the 2 O Rings will bind and not let go by hand so I gently used a prybar to work it out. Sprayed some lube in between pump flange and engine case when I pried on it to get the O Rings to let go. Be very careful as the mounting flange for the pump is not very thick. gently pried on the pump gear to work it out.
The two external O Rings looked like they could be the cause. The smaller one in particular as it looked like it got sheared alittle on the sharp corner of the water pump cavity. I took a scraper and emery cloth and made a radius on the sharp part on the case. Once pump is out, run your finger in and out where the O Rings enter the cavity and you will feel the sharp corner that I believe messed up the O Ring.
Put back together and Filled oil and coolant back up and now trying to get it started. Spark but no go???

if its not run in a while you will have problems with the carb being dry
try a prime hose through the carb and just a bit of gas pull hose out and crank
with throttle closed
if it tries to run thats good as it will draw enough to get the carb going

i have found letting mine set is its worst enemy as the carb looses its prime after about 4 days or less
dave

So I shot some starting fluid in air box and it fired and ran for a bit. I'm thinking the carb priming thing is happening .
So I took carb apart and definitely has little holes plugged so trying to clean them out and ran into a question. Between the main jet and pilot air screw there is a slotted head screw idol jet??? that has a bunch of tiny cross holes in it that were partially plugged . I thought I remember on other carbs that this jet had a small hole going all the way thru it length wise. This one either does not have a hole all the way thru or it is really plugged up.
Can you tell me if it should have a hole up the center or not? I can
drill a hole in it but don't know the size? Thanks Rob

Can someone tell me about the side stand switch? I see the switch but looks like the wires have been broken off. I'm having a hard time finding the other end of them. I think they should be colored brown and brown/white??? Do they need to be separated or wire nutted together for bike to run? thanks

it is really plugged up.

this is what happens with ethanol in them and then they set not used

see my pm in your mail box

thanks Dave, reading about relay 19, 30 now. Will take carb off tomorrow and reclean again. The idle jet one with the cross holes but no center hole was plugged. I took a very small drill and put it in a pin vise and worked it thru the center and pulled out some of the gack stuck in there . didn't see any brass chips so I hope I didn't ruin it. Would a ultrasonic cleaner get the hardened crude out of the little holes in the body of the carb. I think some of them are still plugged.

give the ultrasonic cleaner a try with some sea foam
may take a bit of time like hours or days
set the whole mess outside so if there are any fumes you or the shed are not at risk

one of the big problems with mine is bad fuel

Replaced fuel with non ethanol and changed out both relays. fired right up in no time and idled and reved up . AMAZAZINGZING. going to go ride it around and get oil and coolant good and hot then change oil to get rest of water out . May take a few changes. I'll watch oil and coolant to see if coolant drops and gets in oil . I don't have new oil filters yet so I am running it wo any oil filter. Will that be a problem? Thanks for all your help everyone, rob

k and n 151
hi flo 151
rotax 500cc uses same filter

and get one back in there before a piece of trash kills some thing

good trail bike shop should have one the recent BMW small 300cc bikes and one of the 650 cc bikes used it also

dave

this is a great running bike get it fixed and be good to it and it will return the love

Put 63 miles on it , Ran great but a little stubborn to restart when hot.
Temp light never came on. Only thing I need to fix is a coolant leak up on top somewhere. Also after I stop coolant comes out radiator overflow tube. There isn't a recovery bottle on it ? Should it have one?

hh
Has an annoyingly after market loud muffler on it.
Anyone have a stock muffler they want to sell? Mine has "M4" decal on it. More like a glass pack then muffler.

look for a bad hose or clamps
its 16 years old
recovery bottle maybe for a while you work on it
antifreeze on tires is slick and dangerous
but never seen a bottle on one
when you get the leaks stopped there is a water additive for bikes that make them cool better
also test your fan

and put a stock pipe back on it if you can find one
trying to get to get them to go faster just screws them up