20th Apr 2011, 12:54

Try cleaning your carb and checking the top end; it might have a huge carbon deposit in it. Check for worn rings or piston too...

24th Apr 2011, 00:19

Stock pipe better for long distance or top speed.. chamber best for less than 1km only. Cannot go more than 1km..

12th Jun 2011, 09:30

Hello. I am interested in your post about your motor performance. I have done many things to make my Y125ZR run at the desired speed, but still failed. I sometimes feel psychologically down, using that Yamaha RXZ carburator, since there's been no changes to my 125ZR's performance. Maybe I should try your method to get things to change. Thanks.

26th Jun 2011, 02:47

What is the enduro piston?

29th Jun 2011, 10:26

Hi, I'm from Greece, and I want to ask why the Supersport Yamaha 125zr, and generally 2-stroke motorcycles, have not been on the market since 2002 in country. Please be patient and answer my question; I want to know the reason.

20th Sep 2011, 03:49

In my opinion, 2-stroke bikes usually produce more smoke compared to 4-strokes.

11th Mar 2012, 22:16

Try to use sprocket 15-35 415 SSS. My bike can reach 180 on the highway...

15th Mar 2012, 02:21

It's easy, use an RXZ carb and porting exhaust hole. Send it to an experienced foreman.

12th May 2012, 21:12

I have a problem... My 125z 2nd gear could reach 80km-100km.. But after a few months, 2nd gear can only reach 60km... What happened? Can anyone tell me?

26th Nov 2012, 10:56

I'm using all standard for my 125z... But if I used RXZ porting carb for my 125z, what is the main jet, air jet etc??

9th Feb 2013, 10:51

Hi! Does anyone know a shop that sells the disc rotor (disc brake) for the Y125? I have seen Yamaha/YYPang/Motul race bike JupiterZ that has the disc rotor on. It is a bit small, and I think it is a bit lighter weight than the 300mm disc rotor.

And one more thing, does anyone here know any e-mail address of Yamaha Thailand, because I'm trying to contact them and order some parts for my Yamaha X1/Lagenda 110/Jupiter Z, but the e-mail address on their website is not working.

Thanks a lot and ride safe!!!

Please e-mail me at: jrk_rt@yahoo.com

16th Sep 2013, 14:22

Yeah... I've got the same problem too... but my friend told me that all bikes will be like that when the engine is cold...

21st Sep 2013, 12:16

Hi, I would like to ask something about the 125z. I'm using a 32mm Uma racing carb, and my block was oversized to 2.0. I still want to know where can I find this kind of block and piston? My 4th gear can reach 150 to 160 easily. Please give me some comments on what I should install to make 200 km/hr.

26th Nov 2013, 18:28

Hi. Where is the workshop that did the modifications for your Y126Z? I wanna send my 125Z to your foreman too.

8th Dec 2013, 00:45

This is the method. Simple.

Sprocket set to 15-35. Pilot jet set to 29.5. Mainjet set to 300. AHM exhaust. Block rebore to 57mm using DT125 enduro piston. Then polish the block, skim the head and polish it. Using a standard clutch plate and also any racing spring will do. Change the CDI to Racing Bee.

So far my 125Z could hit 170+ in 4th gear. The rest I couldn't calculate due to the meter only reading up to 180 km/h. Try this and PM me again on xiao199220091@hotmail.com.

22nd Jan 2014, 11:07

What is the brand of your carburetor? Email me at saijin88@yahoo.com or Facebook musjikz@yahoo.com


28th Feb 2015, 14:29

What is your sprocket size?

18th May 2015, 03:57

Hello everyone, this post still exists? Maybe we can discuss more about the Y125zr?

11th Aug 2015, 06:00

What is the best carburetor for a Yamaha RX135, 5 speed, 2 stroke bike? Is UMA a good brand?? Please advise.

13th Dec 2015, 09:44

What carb do you use?

19th Jun 2016, 05:32

125z meter is 15-20km/hr lighter. So if you're at 80 on your meter, you're only riding at a speed of 60-65km/hr

25th Jul 2016, 18:59

The perr sound that you are describing is just normal if you are using a bigger carb, just let it pass 6,000 RPM and that "perr" sound will be gone and all you'll just hear is the furious sound of your exhaust... Remember, 6,000-9,000 is the powerband of the 125Z if you wanna have fun.

25th Jul 2016, 19:04

Overhauling your 125Z will cost 150-200 US dollars here in the Philippines.