OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Freakshow on February 01, 2011, 10:38:11 pm

Title: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: Freakshow on February 01, 2011, 10:38:11 pm

Pulling a gearbox down and im not sure its what it is supposed to be or not.

do any of you Yam guru's are the 125 ratios in the box the same in the mx and the yz ? i know they changed little parts and like the paint but not what was changed altogether.

does anyone have the number of teeth from the gearwheel somewhere from a 125yzA ?

the gears on this main shaft are as follows, unless im a shit counter which is also possible there were are as follows

30T - 22T - 26t - 24T -22T and the idler 25T 

cant be fugged trying to count the other set, but should be able to get close to an answer from these if anyone knows even if the top of you head if they sound right would help.

cheers

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: Nathan S on February 01, 2011, 11:06:15 pm

YZ125A gearset is closer ratio than MX125A.

The MX shares one gear with the DT125A (3rd?) and the YZ shares one gear with the MX (1st?).

I've got the numbers somewhere - can't recall where right now, though.

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: Davey Crocket on February 01, 2011, 11:27:30 pm

I can look in my parts book toomorow Freaky.

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: Freakshow on February 01, 2011, 11:33:37 pm

thanx.  i just dont want to put this motor back together like this, if i have the wrong box in it, be a bit pointless.

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: YZB 500 on February 02, 2011, 06:29:47 pm

Freakshow is a YZ125C 1976 motor any go to you?

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: crossedup2 on February 03, 2011, 09:50:41 pm

Alright Freaky

After much digging in the shed I found the Clymer Piston Port book whick includes the YZ125A and MX125A.
So according to them;

       YZ125A                    MX125A
1:     34/12                       34/12
2:     31/15                       30/16
3:     29/18                       26/19
4:     25/19                       24/22
5:     24/21                       22/23

Primary is the same for both.

For what it's worth the AT2MX has the same ratios as the MXA. Your numbers look more like the MX set then the YZ with maybe a cog  from the YZ thrown in for good measure.

Regards
Peter B

 

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: Freakshow on February 03, 2011, 10:01:40 pm

Ok so what your saying if the book is right is i have been sold a bunny.............. doh

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: Freakshow on February 03, 2011, 10:06:03 pm

Quote from: YZB 500 on February 02, 2011, 06:29:47 pm

Freakshow is a YZ125C 1976 motor any go to you?

sorry nope, checked the shed, seems i put one in there already. also found a spare frame too.  you interested in the spare ?(http://i33.photobucket.com/albums/d88/munchboxlive/RIMG0531-2.jpg)

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: crossedup2 on February 03, 2011, 10:16:31 pm

Don't known about a bunny, looks more like a pup?
Just to compare;

30T - 22T - 26t - 24T -22T and the idler 25T 

       YZ125A                    MX125A
1:     34/12                       34/12
2:     31/15          30          30/16
3:     29/18          26          26/19
4:     25/19          24          24/22
5:     24/21          22          22/23

What about the rest of the motor? Case numbers and barrel etc?
Is there anything that identifys the the rest of the motor as ZY?

Regards

Peter B

Title: Re: trainspotters whats the gear sets teeth on the YZ125A ? anyone got it handy
Post by: Freakshow on February 03, 2011, 10:45:37 pm

case numbers - possibly restamped.  At least i know now what gear set they used, ill swap it out to a YZ set.  Having to rebuild the rest of the motor anyway now, so may as well do it propally i guess and get it all right.
cheers for the numbers i may have counted that #22 twice, but i was just looking for a rought direction and you confirmed it any.
thanx