MZ/MuZ Riders

hello.
is the 2002 RT125 restricted?
if so how can i de-restrict it?
also is there any productes i can get that will increase the performance?

regards
Si

some are and some are not

the restricted ones have a sensor unit on the rear wheel
near the disk brake and a wire that runs up the frame to the
cdi box
the cdi box must be changed to up grade it

i think the restriction sensor can be bypass which we can removed it.... if it cant be removed then we can try to use frequency converter which can cheat the CDI... if not mistaken the sensor is run on pulse... the restriction can be over come by removing the sensor or put a magnet or a metal at the sensor so that it will be in a "NC" bypass mode. By removing it it should be in "NO" mode.

that is just my logic idea.... dont take it too serious hehehe...

DAVID THOMPSON wrote:some are and some are not

the restricted ones have a sensor unit on the rear wheel
near the disk brake and a wire that runs up the frame to the
cdi box
the cdi box must be changed to up grade it

here is a link on sprocket changes

http://www.mzriders.com/viewtopic.php?t=49


and some more useful info
http://www.mzriders.com/viewtopic.php?t=804

DAVID THOMPSON wrote:some are and some are not

the restricted ones have a sensor unit on the rear wheel
near the disk brake and a wire that runs up the frame to the
cdi box
the cdi box must be changed to up grade it

How would I go about de-restricting my SM125?

is this a lenthy procedure.

Or just a case of finding the restricter and removing it?


(I have a friend who has been riding his SM for two years now, and he thinks the bike just de-restricts itself after 2000 miles.
as he is now getting an extra 20mph, does that sound likly to you?)

P.S. Thanks for all your help trying to fix my idle problem but it just fixed itself after I refueled.

heheh i think after 2000 miles the sensor went kaput. .. when the sensor kaput which gives the bike no restrictions... u may try to remove it

herbalist wrote:

DAVID THOMPSON wrote:some are and some are not

the restricted ones have a sensor unit on the rear wheel
near the disk brake and a wire that runs up the frame to the
cdi box
the cdi box must be changed to up grade it

How would I go about de-restricting my SM125?

is this a lenthy procedure.

Or just a case of finding the restricter and removing it?


(I have a friend who has been riding his SM for two years now, and he thinks the bike just de-restricts itself after 2000 miles.
as he is now getting an extra 20mph, does that sound likly to you?)

P.S. Thanks for all your help trying to fix my idle problem but it just fixed itself after I refueled.

is there anywhere that i can order a new exhaust from

btw - thats a better / louder exhaust, not the box standard one

simon wrote:is there anywhere that i can order a new exhaust from

btw - thats a better / louder exhaust, not the box standard one

You can try to see if there is a dealer for M4 exhausts there. I have one and it sounds great (braaap).

I'll try to get pictures up of my bike. The can is scratched a little from racing, but you can see how nice it looks on the bike.

DAVID THOMPSON wrote:some are and some are not

the restricted ones have a sensor unit on the rear wheel
near the disk brake and a wire that runs up the frame to the
cdi box
the cdi box must be changed to up grade it

Sorry to bump an old thread, but my SM does not have a sensor unit near the back break or a wire.

can I still de-restrict it?

if so how???

if your sm does over 55 mph it is de restricted
i think the restricted models all were for germany
you must add a rear wheel speed sensor and different cdi box to make it a restricted bike

people think these things are restricted for 2 reasons
used to a 2 cycle bike with 5 or 6 more HP

or there riding one that is not broken in ...
mine had a very tight engine and it was almost 3500 miles before it got
loose and would wind up
this thing is a moped between 2,000 and 5,500 rpm ....6,000 to 10,500 rpm its a motorcycle

mine is geared 16x52 and does 69mph flat out at 10,500 rpm
original gearing was 16x49 and some where between 75and 80 was the top speed i saw from it

DAVID THOMPSON wrote:if your sm does over 55 mph it is de restricted
i think the restricted models all were for germany
you must add a rear wheel speed sensor and different cdi box to make it a restricted bike

people think these things are restricted for 2 reasons
used to a 2 cycle bike with 5 or 6 more HP

or there riding one that is not broken in ...
mine had a very tight engine and it was almost 3500 miles before it got
loose and would wind up
this thing is a moped between 2,000 and 5,500 rpm ....6,000 to 10,500 rpm its a motorcycle

mine is geared 16x52 and does 69mph flat out at 10,500 rpm
original gearing was 16x49 and some where between 75and 80 was the top speed i saw from it

Thanks for the info.

This is my first motor cycle, I went straight from cycles and mountain bikes to my beautiful SM125.

My bike will just about hit 60mph if I rev the shit out of it through all the gears but sometimes just seems to cut out at the highest rev's, literally like the throtle is switched off .... it could be the way I am riding it im not sure.

I was instructed by the guy at the bike shop to really rev it through the gears to get the most out of the bike.

You are totally right about the engine being tight, I have done almost 3000 miles and it does feel quicker, and the sound from the engine and exhust is different also, more throaty. less tinny.

How do I find out what my gearing is? and what would be the best gearing setup for my bike, bearing in mind I only use it to commute through London.

I am a novice here but I understand the principles, a rear gear with fewer teeth would give more top speed but less power in the lower gears, right?

I also heard someone mention that the stock exhust could be restricting the power of my bike, do you know anything about this?

My first time there. I've also got a SM125 all standard (fantastic first bike, 95mpg) nearly 4000km on clock, just starting to get bit more speed out of it!! Max speed seems to be in 5th.
Does anyone find the choke a little temperamental?

Top tip: I use 'Plexus' on the plastics it's the best thing ever!!!

first the engine is tight when new 4000 plus miles before it will rev free
mine has a tachometer and 10,500 is red line on it
at rpm below 6000 it is sort of like a nice moped above 6000 it runs like a motorcycle should...
i get 60 to 70 mpg per us gallon... english gallon is 1 and 1/8 us gallons

stock gearing on a sm is 16 tooth front 49 rear i find mine runs better
with a 52 on the rear it is the stock sprocket for the sx
the sprockets are an odd size center hole ESJOT of germany is the only company listing them i think the front is same as a yamaha ya6 from 1966 but can not cunfirm that
phil at BSA in the UK may be able to get a better selection of sprockets than i can here in the USA
if yours has alloy wheels i can send info on how to adapt a sprocket
to it
the 52 tooth runs much better but knocks gas mileage a bit

the speed limits where i live are 55mph and lower except 2 roads which i do not need to use very often
i have been doing some experments with the air filter and every thing i do seems to lower the power and make bike slower so for now i recomend the stock filter
and donot store any thing in the space under the seat close to the air intake as it interfers with air flow to the air box

if you can find a tach for the sm get one if you can afford it
this motor wakes up at 7000rpm and pulls well to over 10.000
the choke is hard to work because of the control on the handle bar
same thing as my saxon tour and it is not to user friendly
start bike with choke on and ride away do not set and idle ....you should have it off after going about 1/4 mile
keep battery in good shape mine blew out the voltage reg because the original battery was junk from setting on dealers floor to long
ar dave

They did two versions of the rt 125 engine. engine version = a or b type.
the A is around 12bhp i think.
the B is 14.6bhp (legal max for people riding on CBTs)
Its stamped on the front of the engine, behind the radiator