Newbie Q&A - 125SM

[witttom]

Glad to see some familiar faces (err... names) around here!

I have recently acquired a 2002 MZ 125SM (dealer demo) as part of a trade involving my 2001 MZ Skorpion Traveller. I've been riding the SM whenever I get the chance over the past couple weeks and am loving it more and more I ride it.



I do have some newbie questions concerning the 125SM though, so please forgive me. I looked around briefly, but didn't find answers to my questions.

Where do I get sprockets? I'm considering going up a tooth or two in the rear to gain a little bit more low end grunt (I can't pull top RPMs in 6th anyway).

Where do I go for aftermakert exhaust options?

I've seen pics of OTHER 125SM's and see that the rear fender has two holes arranged to accomidate a US license plate. Mine rear fender has two holes arrangege vertically, and as such, I have mounted my license plate that way too (which either looks kinda cool, or dorky, depending on your opinion! Hehe). Do people drill these holes themselves, or are there different versions?

I've been enjoying my SM on the street so much, that I have been considering racing it in a local YSR league (it falls within the guidelines/rules of a couple classes). While I have seen some reports of the SM being somewhat heavy, I believe it could actually be fairly competitive if placed in the right class. I'm troubled with this decision though, as I just don't know if I want to take such a sweet street bike and tear it up on the track.

[ptong]

Hi,

I have an RT 125 same engine different setup. There are aftermarket exhausts by Supertrapp on their website, and I am sure you can get a sprocket from an MZ dealer online too. They also have 150 kits, and other items. I would recommend having a look at the 125 posts for cam timing... this is a kit you can get also that was apparently developed by a dude in California who races the SM's.

anyway hope that maybe helps. I don't have the addresses on hand as I am switching to a new computer.

[witttom]

I have an RT 125 same engine different setup. There are aftermarket exhausts by Supertrapp on their website, and I am sure you can get a sprocket from an MZ dealer online too. They also have 150 kits, and other items. I would recommend having a look at the 125 posts for cam timing... this is a kit you can get also that was apparently developed by a dude in California who races the SM's.

anyway hope that maybe helps. I don't have the addresses on hand as I am switching to a new computer.

I poked around on the SuperTrapp website, but didn't see anything. I also inquired with the somewhat-local MZ dealership from whom I acquired the SM, but have not heard anything back yet. I think I am probably going to hold off any any major performance work, as sprocket changes and a better flowing exhaust may satisified my wants/needs without getting too radical.

[witttom]

Oh... another newbie question about my 125SM. I noticed recently, that I have some very small cracks/chips in the paint near the back left side panel. Under the super glossy black paint, appears to be TEAL plastic. ...is this normal or have I got my hands on a SM that was previously teal in color?

I am technically the original owner for my SM (I had the first title made from the Certificate of Origin), but the dealer used this bike as a demo. It only had 428km on it when I got it. I would find it odd that he would have painted a new bike.

[micheleen]

My yellow SM is green under the flaked paintwork of the seat/rear bodywork, I think they're all the same colour for that moulding.
For exhaust and rear sprockets try Ksports

Cheers, Mike

[witttom]

For exhaust and rear sprockets try Ksports

Awesome. Thanks for the tips!

[jbthumper]

my "used to be"yellow SM had teal coating underneath...but black plastic...

i guess they've got various under-coats..hehehe
what ever turns you on MZ....


witttom,IMHO,when getting a supertrapp,make sure you're ready for the morning rumble...could be too loud for some....

check-out powroll.com too...

[witttom]

witttom,IMHO,when getting a supertrapp,make sure you're ready for the morning rumble...could be too loud for some....

I don't mind loud exhaust, as long as it has a good tone. I've owneed some bikes and have seen plenty of others with SuperTrapps, and I have to say that they nomrally (but not always) tend to have a bit of a harsh raspy sound to them. If I had a choice between a soft sounding stock exhaust and a raspy exhaust that breathed much better, I think I would still go with the raspy exhaust.

check-out powroll.com too...

I'll check that out too! Thanks!

[witttom]

check-out powroll.com too...

Powroll has the Supertrapp IDS2. It is $280 for the RT125 (shown below) or $291 for the SM/SX (which includes the "S" pipe).



They say this is an aggressive/torquey sounding muffler that increases HP by 15% or more.

Anyone know where I can get a better deal?

[witttom]

For exhaust and rear sprockets try Ksports

KsportMotorcycles.com has the Alien DMC slipon for $199. I've never heard of this exhaust. Anyone have any expereience with it?




They claim an extra pony.

Rear sprockets (45T to 60T) are $49/ea.

[DAVID THOMPSON]

hello tom
i have a rt125
and the only issue i have is be careful about doing something
that stalls the motor i have broken the starter freewheel
twice on mine
do a search on freewheel or starter clutch in the search menu on this site
this part i recomend for your personal spairs
it will be 2 weeks friday since i ordered one
the part numbers on request

my total down time in 3 years because of this part is approching 50 days
3rd one to be installed as soon as it gets here

i have a 52 tooth from an sx on the rear 69mph is flat out top speed
but it sure does hills in southeastern ohio very nicely
and motor needs about 4000 miles on it before it rev's freely
and with 16/52 65mph =9700rpm yes 9700rpm in top gear
and i run it at 60 to 65 for 5 or 6 hours on trips
need it meet you some where in southeastern ohio some time and
shoot the bull

[witttom]

hello tom
i have a rt125
and the only issue i have is be careful about doing something
that stalls the motor i have broken the starter freewheel
twice on mine
do a search on freewheel or starter clutch in the search menu on this site
this part i recomend for your personal spairs
it will be 2 weeks friday since i ordered one
the part numbers on request

my total down time in 3 years because of this part is approching 50 days
3rd one to be installed as soon as it gets here

Hi Dave! (yes Dave, it's me Tom from SW Ohio! )

I recall seeing you posting this on the MZOG on YahooGroups a short while back. I remember seeing something about stalling and rolling backwards, but I'm still not quite clear on the actual cause. What happens to cause it to break?

Just curious (I've not tried it yet) but how difficult is it to push start these?

Went riding this evening with an SV650 friend. I think I may have pissed him off, because I pretty much maintained one speed. 55mph in the straights, 55mph in the sweepers, and 55mph in the tight turns. Hehe... He would easily catch me in the straights but drop back in the tighter stuff. After a 1/2 hour of that, he broke off and went home. He doesn't have a great deal of miles under his belt yet this year, so I think it may have been a little too much for him.

I had a GPS with me this evening too and discovered that the speedo appears to be roughly 5% off. I'm not surprised, as most motorcycle speedometers are optimistic, but I had hoped it would be dead nuts accurate like my Skorpion was (well, it was only off about 1%). My top speed this evening on a flat straight surface (as shown by the GPS) was 69.6mph. I probably could have squeezed out a couple more by dropping down into 5th!

[DAVID THOMPSON]

it trys to run the starter backwards and it just blows up from the pressure
before you can get the clutch pulled in

[bdalameda]

I have a DMC Alien Exhaust on two of my Mz125's. They are really loud. Also due to the reduced backpressure the engine runs better with a 3-5 degree advance on the intake cam. Basically this is the K&S Mod. I built my own baffle insert and added the DMC spark arrestor. This quieted things down a bit but still improves the power output. I would really consider using the Powroll exhaust as I think it is better tuned than the DMC.

As to the Freewheel. I had experienced two freewheel failures previously. After looking at the e-start mechanism I discovered that the reducer gear has a slip type clutch in it that is kept in tension by a wave washer. This is designed to give the system some slip to prevent the freewheel from being over torqued. I took apart the slip clutch and noticed that the two mating surfaces of the clutch were gouged. This was preventing the clutch from slipping and kept the starter drive system directly coupled to the motor when the freewheel clutch was engaged. I polished the mating surfaces and relieved some of the tension on the wave washer which allows the slip clutch to slip easier. I haven't had a problem since even with the 150 kit installed, it has been over a year now. The only difference I notice is that the slip cluch slips slightly when the engine is cold and I engage the starter. This doesn't prevent the engine from starting but it definitely protects the freewheel from being damaged.

[DAVID THOMPSON]

hi thanks for the input i was looking at that part
comments? on how much to back it off
ar dave

As to the Freewheel. I had experienced two freewheel failures previously. After looking at the e-start mechanism I discovered that the reducer gear has a slip type clutch in it that is kept in tension by a wave washer. This is designed to give the system some slip to prevent the freewheel from being over torqued. I took apart the slip clutch and noticed that the two mating surfaces of the clutch were gouged. This was preventing the clutch from slipping and kept the starter drive system directly coupled to the motor when the freewheel clutch was engaged. I polished the mating surfaces and relieved some of the tension on the wave washer which allows the slip clutch to slip easier. I haven't had a problem since even with the 150 kit installed, it has been over a year now. The only difference I notice is that the slip cluch slips slightly when the engine is cold and I engage the starter. This doesn't prevent the engine from starting but it definitely protects the freewheel from being damaged.