Mz sx125 gear shifting issue

SM, SX, RT, FunX, and models re-branded as ATK in U.S.

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Mz sx125 gear shifting issue

Postby DougieL » Wed Jul 06, 2016 1:33 pm

Hello everyone hope someone can help I have owned my sx125 for about 1year I've spent my well earned money on it replacing breather pipes,air connectors,indicator and yes uprated spray clutch,tyres,oil changes,carb cleaned and it's running near perfect but one issue I've always had is when I change up mainly between 4-5-6 gears I was getting false neutrals now and again ending in screaming revs until I manage to change gear .ive recently started holding the gear lever up until the bike drives somtimes I get a delay until the engine drives and the gear locates I was wondering if anybody else suffers this with the Mz 125's rt,sm or sx versions or do you have a suggestion cure what might be causing this problem thanx dougie
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Re: Mz sx125 gear shifting issue

Postby DAVID THOMPSON » Wed Jul 06, 2016 2:37 pm

check the clutch cable out and make sure it working OK and adjusted proper
check chain sprocket is it loose at the output and chain for proper tension not too tight or loose
change the oil and do not try shifting fast also make sure the lever is proper mounted on the shift rod
page at grahams
http://grahamsmotorcycles.com/web/125_Gear_Shift.htm

items 7 am 19 do the shifting if they are worn out
they may be the problem... there are little pins on 7 if worn they can be a problem
19 can also be worn
clutch basket may need removed to see
crank nut may have reverse thread
do not remember it's been since 2004 since i been there doing any of this
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
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Re: Mz sx125 gear shifting issue

Postby DougieL » Fri Jul 08, 2016 10:54 am

Thanx for the help but before I go drastic and start going all mechanic I have checked oil level and it looked below minimum had to add about 0.2 litre to get in between marks hope this might help also I have noticed when I engage 1 st gear without engine running with clutch fully disengaged /lever pulled fully back I'm suffering from slight clutch drag through all gears is this normal for Mz's
MORK CALLING DAVE COME IN DAVE MORK CALLING DAVE COME IN DAVE
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Re: Mz sx125 gear shifting issue

Postby DougieL » Fri Jul 08, 2016 12:36 pm

Thought I'd throw a picture up just as a legend lives on
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Last edited by DAVID THOMPSON on Fri Jul 08, 2016 2:15 pm, edited 2 times in total.
Reason: picture was up side down
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Re: Mz sx125 gear shifting issue

Postby stephendacosta » Tue Jul 12, 2016 8:08 am

It is not normal for the clutch to drag.
Stephen DaCosta
1995 Skorpion Sport; ten-MZ 125's;2009 BMW G650GS;1981 GS450 Suzuki Roadracer
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Re: Mz sx125 gear shifting issue

Postby DougieL » Tue Jul 12, 2016 11:48 am

Reckon clutch plates could be warped or can I adjust at the clutch inside the engine maybe sort it out ,also what oil do you lot use for best results I use mogul 15w-50 is this causing drag ,previous owner treated it terrible I think it was low mileage but I've had to alter ,clean everything takes the shine off it cause these are wicked bikes when working right
DougieL
 
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Re: Mz sx125 gear shifting issue

Postby DAVID THOMPSON » Tue Jul 12, 2016 12:13 pm

there is adjustment inside on the basket
if its off then the lever will not get a full pull
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
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DAVID THOMPSON
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Location: Parkersburg, West Virginia USA .questions answered MZ 95 up, BMW 1953 to 1979 and ham radio WD8CYV

Re: Mz sx125 gear shifting issue

Postby DougieL » Tue Jul 12, 2016 1:37 pm

Thanx for response worth its wait in gold this website ,gonna take it apart and check parts of gears for wear and then adjust clutch oil and filter change due anyway fingers crossed problems are obvious will get back when done in a couple of weeks
DougieL
 
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Re: Mz sx125 gear shifting issue

Postby DougieL » Sat Aug 06, 2016 1:18 pm

Alright everybody update sunny day in Birmingham uk ideal weather to attempt strip down and check gear selectors
Stripped it all down didn't look to bad but springs on fork selector felt a bit weak compared to a spare I had so swapped over ,added new oil pressure Spring while it was opened up ,put castrol racing 10w-40 oil in,Mahle oil filter on ,adjusted clutch away I went ran a dream so the moral is Dave you was right full stop.got hold of some spares really useful sump guard and scorpion exhaust will put on in 2weeks and see how it runs will throw picture up when complete thanx again
DougieL
 
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Re: Mz sx125 gear shifting issue

Postby DAVID THOMPSON » Sun Aug 07, 2016 11:42 am

you mention change in exhaust
the 125 bikes like the factory exhausts fine
the fuel use goes up on any pipe changes i have tried
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
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DAVID THOMPSON
Moderator
 
Posts: 5149
Joined: Sun Nov 23, 2003 11:01 am
Location: Parkersburg, West Virginia USA .questions answered MZ 95 up, BMW 1953 to 1979 and ham radio WD8CYV

Re: Mz sx125 gear shifting issue

Postby DougieL » Sun Aug 07, 2016 3:16 pm

You are right I have read previous posts where aftermarket exhausts have reaked havoc and caused running issues the guy I got it off said he just fitted and used it I might just try it and see if any problems occur if so will rip it straight back off it is a nice carbon scorpion exhaust .i have 2 weeks holiday mid August will try it then and let you know results ,I'm not gonna re jet or anything just fit and test thanx again for your help
DougieL
 
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Re: Mz sx125 gear shifting issue

Postby DAVID THOMPSON » Mon Aug 08, 2016 4:44 pm

the 125 runs very lean and in the USA
it hates the gas with the ethanol added

http://www.pure-gas.org/
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
User avatar
DAVID THOMPSON
Moderator
 
Posts: 5149
Joined: Sun Nov 23, 2003 11:01 am
Location: Parkersburg, West Virginia USA .questions answered MZ 95 up, BMW 1953 to 1979 and ham radio WD8CYV

Re: Mz sx125 gear shifting issue

Postby DougieL » Tue Aug 09, 2016 2:20 pm

I think I just want to here how it sounds on YouTube loads have aftermarket exhausts just curious I suppose maybe fit try then sell
DougieL
 
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Re: Mz sx125 gear shifting issue

Postby DougieL » Sun Aug 14, 2016 1:02 pm

Went for it Saturday sun was shining again got hold of some washers an exhaust clamp and fitted scorpion back box ,adapted second stage from an original exhaust ,fired it up and it roared .Decided to have a street run on it and surprisingly
It was fine ,I noticed the exhaust was running hotter than the original and boy it was louder even with the baffler in.abit too loud for me I think totally different sound ,tone than the original it felt like I had more grunt but I think I might of been more aggressive not sure sounds like a total dirt bike now ,also fitted sump guard
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Re: Mz sx125 gear shifting issue

Postby stephendacosta » Mon Aug 15, 2016 4:09 am

Don't forget to go up a size on the main jet. 105
Stephen DaCosta
1995 Skorpion Sport; ten-MZ 125's;2009 BMW G650GS;1981 GS450 Suzuki Roadracer
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