RM125S questions for the Guru's

[bazza]

https://www.facebook.com/groups/444737422335541/
scroll down 5-6 photos to see nice restored suzuki 125

[OverTheHill]

had a genuine RM125S once, traded it on my year old YZ250C [airbag fork model], got more enjoyment out of 'that' bike than the 250 despite breaking the end off the crank [at the LH main], magnets grabbed the rotor in full flight which was fun when landing with a dead engine. Spent some time looking for spark lol. Big carb & big porting, great aircleaner set up. Another one i shouldn't have sold damn it.

[dodgee]

I had both M & S nos barrels , the only difference that i could see was the M had one more cyl fin at the rear , where the S had it removed to fit the adaptor for bigger carby.

[oldfart]

125 M carb  VM 28SS   Id # 28720      Timing  3.8mm
125 S carb  VM 34SS   Id  #41700       Timing  2.20mm

[Tim754]

Top two piccies show difference in M swing arm, the rest show parts only on S model.

[Doc]

I had both M & S nos barrels , the only difference that i could see was the M had one more cyl fin at the rear , where the S had it removed to fit the adaptor for bigger carby.

thanks dodgee.. basically the same is what I figured. Too lazy to get out the verniers

thanks to everyone for all the reference fodder also

[oldyzman]

I like the RM "S"
Brett

[80-85 husky]

ol mate got a job at b15 and left school. with his second pay packet he bought a 2nd hand montessa 125~ about a 73 I rekon. it went exactly 100 metres and exploded. in disgust and embarrassment, he got a loan and bought a new rm 125 s. what a machine for a bunch of kids on dax's and kwaka 75's...agi 100 yammies etc. great bike. he never raced it and dropped out of bikes after his first headj@b

[albrid-3]

ol mate got a job at b15 and left school. with his second pay packet he bought a 2nd hand montessa 125~ about a 73 I rekon. it went exactly 100 metres and exploded. in disgust and embarrassment, he got a loan and bought a new rm 125 s. what a machine for a bunch of kids on dax's and kwaka 75's...agi 100 yammies etc. great bike. he never raced it and dropped out of bikes after his first headj@b

Now that was funny.

[pmc57]

Here's a trio of the little monsters at last years CD10

[80-85 husky]

that first hdjob destroyed a lot of promising riding careers....

[Tim754]

And yet the Suzuki parts books I have appear to list no different barrel between the two I better look harder

[oldfart]

It's not very often you get to  see 3 nice clean Rm 125 S sitting next to each other.

[John Orchard]

Ok draggin-up an oldie but subject matter was not completed.

RM125M cylinder 12110-41001
RM125S cylinder  12110-41002

I just got an American listing for their kit '75 RM125's. If you find a 12110-41002 listed anywhere, check on the actual description, American Suzuki have the description wrong, it is listed as a TM125 piston.

I actually just bought a piston off ebay, listed for a TM125, not using the above number but it did have two part numbers on the box (12110-41731 & 12110-28753, the latter number is the kit piston for the S, all websites list it as a TM125 piston), it was $12, it arrived today, it is a kit 'S' piston, with .6mm ring grooves, obviously the dealer kind of knew it would not fit a TM (although it will with .6mm rings).

So, I now have the part number for RM125S piston rings, again, American Suzuki have the description wrong, they are listed for TM125 ! but I figure the ebay selling dealers might know they won't work on a standard TM piston but they don't know what, so they are super cheap, I just bought a set for $10 :-)

[sleepy]

I just had a look in my RM125 M,S,A&B parts book and the 11210-41001 part number is before frame number 18508 and the other note says for the 002 barrel use 13125-28701 inlet gasket. In the back of the book there is a section for parts that are different for the "S" and the barrel isn't mentioned. The only things different are the Carb, airbox, piston(12110-41730), pipe and CDI bracket and wiring. Rings as well 12140-28740.
Happy to scan the "S" pages and send through if you want.
I've heard people say the S barrels were hand ported in the factory and the couple of S barrels I've seen did have the inlet port cleaned up pretty well but the parts book doesn't show it as a different part so without having an original M and S side by side I can't say. Could have been that part way through the M series the S barrel became fitted.