1975 RM125s

[Graeme M]

I sat on an RM125M in 1975 at my cousin's place. At the time, I had I think a TS100, and the RM was just sooo lustworthy! I have loved the look of those things ever since, and finally a couple of years ago bought one. I love it. It is fun to ride, handles just fine for an old clunker, and is a definite keeper.

I know a lot of others feel the same way.

So, let me know if you have an RM125M or S, and if possible, post up a pic as well. What have you done to yours? Do you like it?

[Marc.com]

I have one that we dropped a TS185 engine in about 25 years ago (god that makes me feel old)

Still starts second kick, one day i will give it a birthday/

[oldyzman]

HEY GRAHAM,
That is a nice unit! You have seen the pic of my one by now. Just wanted to compare notes on jetting. When i picked up the bike Nev said that it may be ea little lean so before i rode it i richened it up.
The spec said: MJ 280    pilot 35
IT had             MJ 190     pilot 35
I put                MJ 250      pilot 35     was OK but lacked low down power
                       MJ 240       pilot 35       same
  The needle clip has always been centre. I moved it to the top and found that the low down power got better, this is the best i have found. My next move is to maybe go to a 30 pilot and put the clip back to the midle position. By the way The altitude was approx 350M at hartley and approx 50m wrapping around the streets of Lugarno.
Any suggestions will be appreciated. What do you run?
Cheers Brett

[PERM250]

me to i must say that i love my( s ) i had rm125a many years ago and p.Mc 57 had anew s. and he gave me a big hand to rebuild my s that i now have. i will be taking my s to cd 6 is any body else??

[DR]

I have to admit I do prefer pre'75 bikes and whilst I love the snappy power of the RM125S I just could not come to grips with the bike in it's entirety. I felt I was slower on the RM than I was on the TM even though I had 10 or so extra ponies. Best thing I ever did was drop an S motor into the TM and instantly I found what I was looking for. It's not a competitive thing on the rougher tracks but on most of the tracks I'd ever ride nowdays it wouldn't be overly disadvantaged. 

[Graeme M]

Doc, I can't believe you prefer the TM! My TM was horrible to ride - the forks flexed and twisted and bottomed and topped, while the rear shocks were terrible (US Progressives). It was OK on the dirt track, but only just, and there it was as slow as. The RM is a way better bike, although I am suspicious that my RM is like my TM - slower than it should be.  The RM has YSS shocks and much much better forks, and it steers and handles infinitely better.

Brett, my RM is an M so it has a stock 28mm carb. I doubt my jetting will be at all useful. That said, my TM was ported and had a Circle F pipe and K+N clamp on filter (no airbox). I added a 34mm Mikuni and that worked very well, it was definitely quicker. So... maybe the jetting from that is useful to you.

I tried a starting point of:

Main jet: #290
Pilot jet: #35
Needle jet: P-2
Slide needle: 6DH4-2nd
Slide cutaway: 2.5
Air screw setting: 1.0 turn out
Float level: 9.1 mm

Which was OK but seemed a little lean. I ended up with:


Main jet: #310
Pilot jet: #35
Needle jet: P-4
Slide needle: 6DH4-3rd
Slide cutaway: 2.5
Air screw setting: 1.5 turn out
Float level: 9.1 mm

That seemed good but I was racing DT here in Canberra (altitude about 560 metres and the weather was cold). You can see I went UP on the mainjet compared to your jetting. I can't remember now and I didn't make any notes but I think I actually ended up going to a P6 needle jet and back to a 290 main or thereabouts, but that might be a complete lie!

In any case, I'd say something like a P2-P4 needle jet, stock needle, 35 pilot and about a 260-280 main would seem correct, and possibly even bigger on the main if you are dirt tracking it.

[DR]

Graeme it maybe something to do with the fact I weigh under 50kgs and 4 inches of travel is fine as that's all I need seriously I wouldn't ride this bike at Connondale as it is more an RM suited track but at somewhere like Nudgee it's at it's best. The 125 A B and C's I love but on an M or S I just don't feel as confident

not for sale sorry Wasp but it wasn't a hard 1 to build

[oldyzman]

Bloody neat TM,
Hello Graham, Thanks for the info on the jetting, I think i had better refer back to your reply and check the needle jet in mine as i couldn't even get it to run very well at all with a 270 Main jet and the altitude between where i tested at approx 300 compared to canberra is only 200 difference therefore it might equate to a 5% change taking into account the temp difference also
Maybe i should stick to the YZ's
OLDYZMAN

[dodgee]

yea i have a rm125 m and a rm125 s dont ride the m just the s . will have them both at cd6.
dodgee

[mainline]

Is this the same as yours Doc?



http://cgi.ebay.com.au/SUZUKI-TM125-CLASSIC_W0QQitemZ280340261603QQcmdZViewItemQQptZAU_Motorcycles?hash=item280340261603&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50

[DR]

yea, Dodgee has 2 absolute stunners and here's a pic of one, the picture was taken a few years back at the oz titles at Coffs but the bike these days looks similar or maybe even a little better! I couldn't come to grips with it but then a young guy by the name of Adrian McIntyre hopped on and proceeded to blitz near everything of all capacities in the 'All In' race at the end of the meeting. It is bloody fast in the right hands but sadly I just don't have the skills or energy required to get the best out of an RM125S.



I be building another TM hybrid similar to the bike below after CD6 but not sure which way to go with it yet. It may well be RM125S powered also
 


My '71 TS125R also has the S motor at present. I do love the engines but as I said, the rest of the package just doesn't do it for me even though they were probably the closest thing to a factoy bike you could buy. This could be because I'm not really an out and out racer but more a lazy social rider who prefers to ride at about 75%



Mainline no not really except for the tank stickers. I like the plain ol' '75 TM graphics so I normally run them on all my TM/RM125's. Life started with a bare frame (usually a donated John West reject ) I believe it's Donny at Coff's who supplied this frame. I think it was a '73. I found a '75 swingarm, TS185 solid mount rear hub, RM100A front forks, RM125S front wheel, the S motor came from CQ and the rest came from here and there mostly from ebay and like minded friends.

Sorry for the rambling and topic deviation, I'd never ever owned a 125 until about 2007. My first ever ride on a TM125 and an RM125S was the Coff's titles 2007 but after that meet I was totally hooked on these little screamers. They are fun units in all shapes and form be it TM/TS/RM, think I have about 6 already that fit in with the pre'75/'78 era but always looking to build more

[NSR]

Doc
Are you bringing the vinduro bike to CD, Hope so It's awesome.
Noel

[DR]

not sure NSR, I'd kind of like to but I have limited space so I've really got to sit and decide. The 400C is a definate and the other spot was going to be the RL250 but I maybe able to fit in another since the RL is pretty narrow

[DR]

this is Dodgee's 125M resto. 1 of the best I've seen anywhere

[NSR]

It will be worth it for the enduro loop
Noel