Topics

31

General Discussion / Rossi has gone insane.

« on: October 26, 2015, 10:07:22 am »

His Thursday press conference saying Mark Marquez is working with Lorenzo wasn't even backed up by the events (let alone results). Marky Mark rode like a magician to take 5 points from Gerorge on the last lap of the Australian GP (the event being discussed.)

Then in the race yesterday, after some of the best/hardest/clean racing you'll ever see; Rossi "brake checks", runs compleatly off line to force MM of the track, and depending on your point of view, kicks at his rival.

Anybody else would have been DQ'd immediately.

Rossi and the FIM have both lost a lot of respect from me.

32

Tech Talk / 2 stroke tuning. Dyno? Sunshine Coast QLD

« on: October 22, 2015, 11:26:08 am »

My RM125X project.

The original carb, a special Mikuni, made for Suzuki as far as I can make out. (Possibly only minor differences, like front mounted vent to clear the case... Possibly.) was discarded by the PO.

A generic brand new Mikuni has been fitted.
I've shortened it slightly, I think mimicking the original.
Jetted it as close to stock as possible. Inc NOS needle (another Suzuki special)
It runs pretty good WFO and plug chops look ok. (50/50 Avgas PULP)

Trying to get the midrange, (ANY midrange!!)  a bit better I've tried the clip position from top to bottom. Not much difference. A bit "fluffier" full rich. (I think I'm an insensitive test rider)

I'd like to put it on a dyno, preferably with a "sniffer" up the pipe. (Can this work with smokers?)
I heard there was a specialist near Woodford QLD (Sunshine Coast Hinterland) but can't track him down.
Anyone know of anyone?
Any other tips? (Apart from buying a 250/465 which I might be able to ride... 18yo Simon didn't need no stinking midrange!.... )

33

Tech Talk / Tapered steering bearing conversion

« on: September 06, 2015, 01:29:05 am »

I bought an All Balls kit for my RM125X
Instructions include: turning down the stem!

Can the stem be pressed out? Or do you need a lathe big enough to spin the bottom triple clamp (scary propersition)

Anyone done it?

34

Yamaha / YZ465H or YZ250H as an Evo bike

« on: September 05, 2015, 12:06:35 am »

I'm considering looking for either a YZ250 or YZ465 1981 model, as an Evo bike.
Depending really what comes up for sale.

Even though I'm pretty slow these days, I'd like to buy a bike that's at least competeive in its class.
Neither has the sentimental value of my RM125X, which I owned "in the day".

The RM is proving hard to ride (narrow powerband wise, so far- work in progress) + reliability of vintage bikes makes showing up with more than one makes it more likely I'll still be racing at the end of the day.

I never raced open class two strokes, but the 465 seemes to have a user friendly reputation. Might be a fun bike to ride around at the back of the pack.
I did race an '83 TT600, in '83.

Just wondering if these models are considered competitive, and if there is anything special to look out for.

Thanks in advance for any info or opinions.

35

Wanted / RM125X (1981) seat base.

« on: July 01, 2015, 06:22:09 pm »

As above.
Seat base to make a "safety seat".
Or a "Safety Seat" complete.

I'm sure a 125Z seat would fit, not sure what else.

Post, PM, text/call 0418689244

Simon

36

Tech Talk / Fork Studs (Suzuki RM in this case)

« on: June 04, 2015, 11:48:03 pm »

Is there any way to replace the four M6x1 studs that hold the axle clamp? (The thread is worn on mine...)
How are the originals held in?

Thanks for any info. I'm sure it's not a rare situation (1981 RM125X specifically)

37

Tech Talk / Newbie VMX Qs

« on: May 18, 2015, 06:55:15 pm »

As per the title.

1. Any issues with running full synthetic oil at 40:1 in a 1981 water cooled 125?
2. Forks. Wow, did they really feel like this in 1981? Is it legit/common to fit Gold Valve emulators, and other internal mods?
3. Is Avgas (leaded) allowed?

Thanks for any replies

38

Introductions / Vintage MX rider

« on: May 18, 2015, 06:31:00 pm »

I've recently taken delivery of a (cosmetically) restored 1981 RM125X.
My second.
The first one, I bought new in 1981 (and sold it in 1982)

I'm currently "Race Preping" it.
Although I'm old and slow, I'm planning to ride it at my favorite local track: Conondale, and some "back in the day" tracks: Dargle, Lakes. Before I hang it on the wall.
(I occasionally race a modern MX bike. Too many events have 35+ as their "oldest" class, what about us "Veterans"? What about a 50yo+ class?? ?)

I'm on the Sunny Coast,QLD,  but often travel south to the Newcastle area.

Simon

39

Tech Talk / Jetting/Carb options 1981 RM125X

« on: May 18, 2015, 06:24:18 pm »

I have an RM that has been restored (more cosmetic than "race prep")
It's had a brand new Mikuni VM32 slapped on it. The jetting is obviously generic, and not that close to that listed in the owners manual. I haven't run it in anger yet due other issues requiring attention. See "more cosmetic than "race prep".

I was planning on trying to get the original setup (found the original needle at Suzuki Parts), 2.0 slide available locally......
I figure this would be a good starting point?

Another option (recommended by the Aus Mukuni guy) would be a 35TMX Flatslide.

Although not 1981 kosher, the Flatslide would be legal for pre '85, the class I'd be in?
(New to VMX, plan to race it a few times at least before I hang it on the wall to remind me of when I was faster - ie 1981 )

I have a "works rep single sided airbox" on the way, so some fine tuning will be in order whichever route I go.

Comments and suggestions sought.