Jetting/Carb options 1981 RM125X

[skypig]

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.

[Nathan S]

You can't run a TMX in Pre-85, unless you can prove that the TMX existed in 1984 (which you won't be able to prove). The TMX is a very different to the original Mikuni flatslide.

A new VM is the best option unless you want to teach yourself the dark art of Lectron tuning. The early Mikuni flat-slides are ultimately inferior to a Mikuni round slide.

In simple terms (for dirt bikes): if the rules allow it, fit a Keihin PWK. If the rules don't allow a PWK, then fit a Mikuni VM.

[skypig]

Thanks.
My steep VMX learning curve continues.
I thought a Mikuni Flatslide was a Mikuni Flatslide...
Although I remember a few fast Lectron equipped bikes back in the day, I don't think I'll go that route.

I'm trying to start with jetting as close to original as possible in the new VM currently fitted.
The needle is on the way..... Slide on back order....

Taking into account the rider skill ( and brakes and suspension) I think the right wrist will be the limiting factor in the carbs performance IE too much slide left in the venturi.

slowpig 

[Slow Pete]

I will be interested in hearing how the single sided airbox goes,  I'm thinking of getting one for my 250X.   Is it from Vintage Suzuki ?   

[Lozza]

Round slide will make more power on the front side of the power curve

[skypig]

I will be interested in hearing how the single sided airbox goes,  I'm thinking of getting one for my 250X.   Is it from Vintage Suzuki ?   

https://www.dcvmx.com/xcart/home.php?mobile_mode=subcategories&list_categories=1

It hasn't arrived yet, so the only feedback so far is that paying in Australian pesos and shipping make it pretty expensive. My current airbox has some age related issues, and I still have flashbacks to 1981 and cleaning 4 air filters.

Round slide will make more power on the front side of the power curve

Which is where I'll benefit most, realistically/unfortunately:)

[MaxPower]

I liked the Floater airbox . I don't know why everyone has issue with it. The flat filters are easy to clean, no glue seams to come apart. Easy to get to. And no guesswork of the filters are seated. Those aftermarket single filters look goofy If Suzuki put those on their bikes people would have something justifiable to bitch about.

[skypig]

I hear you.
I've fitted (this word cannot be overstated.) the single sided set up.
I haven't run it, but unless it now passes CR500s on the straights, it wasn't worth it.

I did it mainly because the stocker had issues like rusted/seized captured nuts and some broken tabs.
Also sucked into the romance of "works replica" and less restrictive.

Pics and ride report to follow.