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The petite MZ...

I asked a question on the MZOG • MZ Owners Group if I should call my bike an MZ or a MuZ. I got some very informative replies. One reply was emailed to me with a link to Wikipedia MZ entry.

What really caught my eye on this webpage was this very petite MZ 125 4 stroke water cooled single.

This is what was said about this bike… “MZ currently manufactures a line of 125cc 4-stroke motorcycles using a new and powerful engine designed in-house. The current MZ 125 produces 15 crank-horsepower (11 kW) and almost 10 lbf·ft (14 N·m) of torque. It is a liquid-cooled pressure-lubricated dual-overhead-cam design with 4 valves, high-voltage electronic ignition and an 11000 rpm ignition cut-off. This is officially the most powerful 125cc 4-stroke engine mass-manufactured and has also proved highly reliable. This engine is used in 4 models of motorcycle, all of which share a common frame. The frame is a tube-steel backbone with the engine as a stressed bottom member. Changes in the suspension, facia, gearing, and equipment make the four models relatively distinct, despite the shared platform. All four bikes feature a 6-speed transmission and dual disc brakes.
The RT-125 is a mini naked sport bike with tasteful chrome accents and aggressive looks and handling.
The 125-SM is a Super-motard style bike with taller street tuned suspension, tallish gearing, and reduced weight.
The 125-SX features the same appearance as the SM but has a suspension tuned more for off-road use, enduro-style tires, and slightly lower gear ratios.
The 125 FunX is a minimalist light-duty moto-cross bike.
All four 125s are capable of speeds over 65 mph (105 km/h), with the fastest being the RT and SM, both of which are capable of 75 mph (120 km/h) sustained speeds. This makes the MZ 125s amongst the fastest sub-250cc bikes available.”

If you are reading this an own one of these please leave a comment and tell us about your MZ 125.

Here is a link to the Offical MZ site and the page for this bike...


  1. Hi!
    I was reading your blog after searching MZ Scorpion, and noticed this entry about the MZ125.

    Our company did a project with MZ back when these bikes were first being introduced to the US market.

    We did tons of testing and created some kits for them - however, MZ was sold before the project was completed. Here's some of what we found out about the little bikes.

    1. We're not sure what dyno they used to get that 15 crank hp number, but the real numbers at the rear wheel were way less than 10 hp.

    2. A standard Honda SL125 will outrun an MZ125 by at least 5 bike lengths in 1/2 mile.

    3. The engine is hugely overbuilt, leaving so much space that we were able to create a 220cc bore kit without sacrificing reliability.

    4. The bike weighs alot.

    5. There is no way in the world that a stock model could reach 65mph. With a lightweight rider, fully tucked, we achieved 59 mph. Though, on the dyno, the bike will show 65mph without wind resistance.

    6. The FunX (with it's streetbike chassis and uber-tall suspension) was the most ill-handling dirt bike I've ever ridden.

    7. The MZ 125cc water cooled engine had tons of potential - this could have easily been made into a very fast 250, with bullet-proof reliability, right from the factory.

    Pam F.

  2. Hi, i have an MZ RT 125 over in the UK. And i have to say, what an amazing bike. I have the 14.6bhp 2003 model which has been on several dyno tests now. And when i first got it, it did 70mph with ease. It now does in excess of 85mph which is nice for what is a still learner legal requirements over in the UK.

    It also runs and sounds lovely. And the handling is superb. Never had any problems except the sprag clutch which is a common MZ fault apparently. But now MZ make the replacement part at cost as its one of the only known fault woth the bike.

    An amazing bike all round, i would recomend it anyday of the week.

  3. Hi there, I have the 04 RT 125 and love it to pieces, the latter part of that sentence becoming more true every day it seems.
    I dont know or claim to know much about bikes so if jon could give me some pointers to hitting higher speeds with my bike that would be great! The real question I want to ask is where I could find a manual for the bike or at least an engine layout and or diagram?
    Any help with this would be greatly appreciated if someone could e-mail me at and I will also check back here for answers...

    To be helpful as well, i've never had problems with the bike and it's great fun to zip around the city with reasonable power and great handling, the bike goes suprisingly far over considering it's weight and appearance. I would recommend this bike but have had problems around norwich sourcing parts.

  4. Hello Fellow MZ 125 Owners,,

    I have a 2003 SM with less that 5k miles on it..
    Im currently looking for a big bore kit and found a few on German Ebay..
    Ive had over 70mph out of mine and no issues at all with her..
    Im in the uk and use for parts..
    Any questions email me on

  5. Had one of these bikes. It rides and handles well. I was easily able to get 130Kmh. I've ridden many 125 models. this is deffinately one of the best. The only bike i enjoyed more due to its handling would be the Honda CBR.

  6. Hi I have an 06 plate mz sx 125 very heavy bike wont lift up with out full revs and dumping clutch.. Ride is smooth power is plenty just needa more ooooomph to get it on back wheel easier... Over all a greay bike love the kawasaki green colour to... Im a uk rider aswell...


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