Yamaha RX/RS125 parts

[chrisc]

Hey guys
Does anyone have any Yamaha RX125 or RS125 parts kicking around they don't want anymore?
Particularly after some engine parts, maybe a cylinder or head, and some front forks (later model ones).

I figure some bucket racers would have torn them up at some point.

Cheers

http://motorbike-search-engine.co.uk/classic-bikes-2/1976-rs125.jpg

[FastFred]

What are you looking for?

[chrisc]

Firstly, the Yamaha RX125 and the RS125 look incredibly similar. Can anyone confirm the interchangeability of the engine parts?
I wouldn't mind a head and cylinder for it. It's a friends street legal run around that I want to give a bit of tickle :bash:

The factory RS125 (70s version with a drum up front) forks have cageless bearings in the steering head and the forks are pretty trash too. We're looking at swapping in a slightly newer/larger pair of forks for it. Open to options on this if anyone has any ideas.

[Pumba]

Yep RS and RX are the same engine mate. Not familiar wit the frames at all because and the differences between the two as the one I was playing with was in an odd ball frame.

I think they switched at some stage between points and CDI ignitions. mine was points and I grafted a AG100 ignition and flywheel on. It made hell of a difference, and reliable.

[husaberg]

Firstly, the Yamaha RX125 and the RS125 look incredibly similar. Can anyone confirm the interchangeability of the engine parts?
I wouldn't mind a head and cylinder for it. It's a friends street legal run around that I want to give a bit of tickle :bash:

The factory RS125 (70s version with a drum up front) forks have cageless bearings in the steering head and the forks are pretty trash too. We're looking at swapping in a slightly newer/larger pair of forks for it. Open to options on this if anyone has any ideas.

I have posted a lot of steering head bearing sizes and fork sizes
I can't remember where? but on the ese thread I think Rob has a link on pg 1000
I think I have posted a MX special porting map that was for a MX100/DT100 (ot sure if they are the same stroke or not)I think that was on a page for either drew or white trash


can you not find an 125 air cooled?

Oh well if the price was right. I will have a look for a RD Yam reed Valve and reed Rubber unless you have you got any. MY RD stuff is at the old mans but i think there is only plastic ones there though you really need alloy ones as they are ment to be better.

I have a map of the Porting for the GYT kit somewhere I think. no clymer

The mx100 had a closer ratio box from memory.yes it did


DT100A MX100

1 3.18 2.83
2 2.00 1.88
3 1.37 1.37
4 1.00 1.09
5 0.80 0.96

Turns out it is a clymer hot up but i will post it anyway it is old but a start. The MX100 has a 26mm carb vs the DT100 22mm
The thing with Yamaha's is better parts from the hotter models can be fitted, but more so for the 125cc bikes.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250368&d=1320829362

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250367&d=1320829362

[chrisc]

Thanks guys!

[husaberg]

Thanks guys!

If you can find a set of forks for a RD250/350 (one of the early ones pre mag wheels) they had the opposed piston calliper and were the same as the TZ's, much better than any of the later stuff. they changed so they didn't have to pay the paternt fees
It would look right as well.
From memory the early wire spoked hubs ones also accept the big floating yam disks in 280 300 320mm if you want to go the 4 pot calliper way for a bit of bling.
They have likely got the small reed valve as well the RD one would probably bolt on.

[chrisc]

If you can find a set of forks for a RD250/350 (one of the early ones pre mag wheels) they had the opposed piston calliper and were the same as the TZ's, much better than any of the later stuff. they changed so they didn't have to pay the paternt fees
It would look right as well.
From memory the early wire spoked hubs ones also accept the big floating yam disks in 280 300 320mm if you want to go the 4 pot calliper way for a bit of bling.
They have likely got the small reed valve as well the RD one would probably bolt on.

Cheers.
56 x 50 bore stroke on the RX/RS btw

[husaberg]

Cheers.
56 x 50 bore stroke on the RX/RS btw

So it is more likely to be based on the Dt125/175 series? that opens up some opportunities.
I have only ever seen pics the ones I remember seemed to be a bit more angular tank more coffin shaped I guess they followed the RD styling.

[chrisc]

So it is more likely to be based on the Dt125/175 series? that opens up some opportunities.
I have only ever seen pics the ones I remember seemed to be a bit more angular tank more coffin shaped I guess they followed the RD styling.

Well there was a RX125 twin which looked like a RD but I don't know if NZ got these:

http://www.kaskus.co.id/thread/50a0adf12775b4156e000142/dijual-motor-yamaha-rx-125-twin-1977

https://farm4.staticflickr.com/3651/3578352497_4d35da4bcc_s.jpg (https://flic.kr/p/6scZwH)Yamaha RX 125 Twin 1975 (https://flic.kr/p/6scZwH) by wimpy kimpy (https://www.flickr.com/people/38856174@N03/), on Flickr

[husaberg]

Well there was a RX125 twin which looked like a RD but I don't know if NZ got these:

http://www.kaskus.co.id/thread/50a0adf12775b4156e000142/dijual-motor-yamaha-rx-125-twin-1977

https://farm4.staticflickr.com/3651/3578352497_4d35da4bcc_s.jpg (https://flic.kr/p/6scZwH)Yamaha RX 125 Twin 1975 (https://flic.kr/p/6scZwH) by wimpy kimpy (https://www.flickr.com/people/38856174@N03/), on Flickr

Ya going out make me get out a mag now aren't you...
they were all over MCM mags in the 70's.

Never seen that twin plenty of RD125's though.

Google is easier than walking upstairs
http://motoprofi.com/bikephoto/2396/yamaha_rs_100_1979_1.jpg

looks like it is based on the 125/175

http://www.yammy100.com/project-175-t26.html

http://www.yammy100.com/will-yamaha-dt-175-motor-fit-in-a-rs100-frame-t1685.html

[F5 Dave]

Well there was a RX125 twin which looked like a RD but I don't know if NZ got these:

http://www.kaskus.co.id/thread/50a0adf12775b4156e000142/dijual-motor-yamaha-rx-125-twin-1977

https://farm4.staticflickr.com/3651/3578352497_4d35da4bcc_s.jpg (https://flic.kr/p/6scZwH)Yamaha RX 125 Twin 1975 (https://flic.kr/p/6scZwH) by wimpy kimpy (https://www.flickr.com/people/38856174@N03/), on Flickr
Well that's clearly an RD engine. Paintwork looks pretty homespun too.

[Grumph]

i've got a DT125 barrel here surplus. was going to graft it onto an MB but Kev went and sold the good spare cases to Dave.....

If anyone local to you is coming to the BoB it could be picked up at modest cost.

[F5 Dave]

Must ask him if he has spare clutch basket bits. Cases gone to good use as has a barrel that I'll bring down.

[husaberg]

Must ask him if he has spare clutch basket bits. Cases gone to good use as has a barrel that I'll bring down.

From memory Dave the other Hondas 4 stroke single clucth bits are pretty interchangeable other than the pressed in center and the pressure plate (they have a alloy one with a larger bearing) they have a wider basket too.
I think that some of them even had the same number of teeth.......

[F5 Dave]

Largely the centre I want as the pressed bit is sloppy on the shaft.

Besides, couldn't be right using 4stroke parts inside my beloved Honda engine