Anyone played with a dial a jet?

[Mazikeen]

Piddling last night I found I have the 36mm on my 300, bit surprised, but I see across the forums quite a spread of this. It truly doesn't matter, however it does mean I now have the option to offset bore the carb, knowing myself, it will happen. 20 years ago I did so to my Mikuni on my IT, just an awesome setup.

Anyway, reviews aside, wondering if anyone has any real world time with a dial a jet system. Something I never played with but have thought of for a long time, it just seems an interesting concept/application. I have no trouble with jetting, takes some time, but ultimately, all my bikes end up bout as perfect as real world compromise allows. I am not intersted in the dial a jet as a band aid for improper jetting is where I'm going, only if the real world proves the claims. I really don't need more power, I think anyone would appreciate crisper response, everyone would appreciate fuel economy, the ability to make adjustements to the mid range/upper end based on elevation/temp is quite intriguing.

 

[andoman]

I like mine!

I have one on an orange 300XC. Complete with Dick's taper-bored carb.
The torque down low of a 36mm and it really, really rips on top!

From what I remember: normal pilot for idle, a rich needle and rich main. The vacuum in the vacuum tube always causes the correct amount of fuel to be pulled into the carb.

There is a dial that you rotate to change the orifice to affect the vacuum. So you can richen or lean across the board. Not for air density, but for over all feel of the power-band. It self corrects for air density.

The draw back for some will be that you can't really change the jetting at different places in the power band. For example, if you want a leaner midrange so you can rip up and onto the pipe and then a richer topend for extended WOT.

Bottom line: It works as advertised.

 

[AZRickD]

The scoop:

http://www.thunderproducts.com/DJ Motocross Action.htm

"Offset-bore"

The Dick?s Racing 36/39 carb mod has five steps: (1) Dick Wilk offset-bores the 36mm carb so that it essentially remains a 36mm carb below one-quarter throttle, but is a 39mm carb above that. (2) The cylinder side of the carb is taper-bored from 39mm to 42mm for maximum frontal area. (3) The intake throat is radiused to eliminate any flow interruptions to the air entering the carb bell. (4) A Boyesen RAD valve is matched to the carb profile. (5) A Dial-A-Jet system is added to provide a massive dose of fuel when engine vacuum demands it.

I guess that's Dick's way of not using an RBDesigns-style plate?