RM125S or YZ125A Whats more sort after

[Nathan S]

Port the barrel on a mx the same as a yz, there would be no differents, read the test shoot out on both bikes, they favoured the little mx.

I'd rate the YZ's internal rotor ignition as the main point of difference - its definitely got better throttle response and the non-dead-straight ignition curve has to be part of the performance difference.
My YZ-A has an MX top end on it, and it is noticably faster than a stock MX-A.

Its academic if you're building a 2010 style VMX race bike because you can easily build a DT125A that blows the doors off a stock YZ125A, but there's more differences between a YZ-A and an MX-A than the tank. And for the purpose of this topic, there's zero doubt that the yZ125 is vast more desirable than the MX125A reardless of their similarities.

[suzuki27]

I had a mate who had a 125 M or S- not sure but think it was the S. The following year I got the RM125 A- biggest difference I remember was the Reed Valve on the A. They were both great bikes; although I never got to ride a YZ 125; but the A was easier to ride thanks to the Reed Valve- and the up- pipe was a plus. IMO it was a great period for Suzuki. A,B,C, models etc.Some of the best pre-78 bikes and a good Evo bike with some fettleing.

[JohnnyO]

I had a mate who had a 125 M or S- not sure but think it was the S. The following year I got the RM125 A- biggest difference I remember was the Reed Valve on the A. They were both great bikes; although I never got to ride a YZ 125; but the A was easier to ride thanks to the Reed Valve- and the up- pipe was a plus. IMO it was a great period for Suzuki. A,B,C, models etc.Some of the best pre-78 bikes and a good Evo bike with some fettleing.

You're right there 27 it was a great period for Suzuki. I had a RM125a and RM125b and they were fantastic bikes especially the B. I remember the S being a lot peakier to ride, particularly with the 5 speed.

[oldyzman]

I think the RM125S had a reed valve to the crank as well as the piston port??? Then the rm125A made a better job of it.
Brett

[JohnnyO]

The RM125S was a piston port just like the TM125 and the RM'A model had crankcase reed induction.. not a full reed valve.

[oldmxracer]

Interesting YZ vs MX test....
http://vintagemx.com.au/?p=499

[vandy010]

to state the obvious,
RM125S is pre~78
YZ125A is pre~75
i like em both but i'd reckon the RMs would be more of a collector thing. they just look super funky with thier RH styling and downpipe.
{i'd have an MX125A over a YZ125A anyday.
oh! hang on a tick, i do have one
i prefer the yellow MX colour scheme over the YZ's silver.
and who races a stock Yamaha anyway?}

[oldyzman]

I know what yuor saying re the MX being a good thing, but there is something about a Aluminium tank even if its not any lighter..
Brett