MX FCR Project (Monster 750).

[Speeddog]

I think they're both to the same scale, one way or another.
It's what I'd do, given the opportunity.

My suspicion is that they are drilled to the same scale.
Likely 0.42mm and 0.52mm diameter holes.

Or they flow them on some apparatus and they flow 42/52 grams of molasses per fortnight at 53.7 degC.

[koko64]

Thanks mate.  Good to get your opinion. My hope was that the only difference was length for reach into the deeper float bowl design.

[Speeddog]

From my staggeringly large selection of Keihin pilot jets:

#62 - 0.0238" drill shank will pass thru, 0.0248" will not.
So hole is between 0.604mm and 0.630mm.

#60 - 0.0238" will *almost* go through.
So hole is very nearly 0.604mm.

#52 -  0.0200" will pass, 0.0208" will not.
so hole is between 0.508mm and 0.528mm.

Not much of a sample size, and it's only the 'short' variety, but I'd bet money.

[l88m22vette]

Cool project, I just got a bike and had posted about the exact same idea, seems like it should work fine 

https://www.ducati.ms/threads/keihin-carbs-anyone-tried-an-oem-version.725957/

[Duck-Stew]

From my staggeringly large selection of Keihin pilot jets:

#62 - 0.0238" drill shank will pass thru, 0.0248" will not.
So hole is between 0.604mm and 0.630mm.

#60 - 0.0238" will *almost* go through.
So hole is very nearly 0.604mm.

#52 -  0.0200" will pass, 0.0208" will not.
so hole is between 0.508mm and 0.528mm.

Not much of a sample size, and it's only the 'short' variety, but I'd bet money.

#62 = 0.62mm
#60 = 0.60mm
#52 = 0.52mm

The numbers aren't random. 

[koko64]

I'm glad they're not Mikuni TM 38's with a wildly different jetting scale to BDST38's or anything else on the planet

[koko64]

Cool project, I just got a bike and had posted about the exact same idea, seems like it should work fine 

https://www.ducati.ms/threads/keihin-carbs-anyone-tried-an-oem-version.725957/

My concern is fitting these carbs and their filters between the frame spars. The 2nd gen carb is fat. It's pretty tight.

From my staggeringly large selection of Keihin pilot jets:

#62 - 0.0238" drill shank will pass thru, 0.0248" will not.
So hole is between 0.604mm and 0.630mm.

#60 - 0.0238" will *almost* go through.
So hole is very nearly 0.604mm.

#52 -  0.0200" will pass, 0.0208" will not.
so hole is between 0.508mm and 0.528mm.

Not much of a sample size, and it's only the 'short' variety, but I'd bet money.

I think they're both to the same scale, one way or another.
It's what I'd do, given the opportunity.

My suspicion is that they are drilled to the same scale.
Likely 0.42mm and 0.52mm diameter holes.

Or they flow them on some apparatus and they flow 42/52 grams of molasses per fortnight at 53.7 degC.

#62 = 0.62mm
#60 = 0.60mm
#52 = 0.52mm

The numbers aren’t random. 

It's good news for sure. I'm hoping to not have to play with float levels too much, it's a great way to go mad.

[koko64]

Ordered the jet from the importer who confirmed the same  size scale. Not far from mock up fitting stage. I'll dremel out the 45 deg manifold boot a little for the spigot to fit.

[koko64]

Some more parts from Powerbarn.
http://power-barn.com/motion-pro-straight-push-pull-throttle-assembly-01-0073/
http://power-barn.com/motion-pro-push-pull-throttle-cable-set-for-ducati-with-keihin-fcr-and-fcr-singles/

[koko64]

https://www.mikunioz.com/shop/tm38-twin-mikuni-flatslide-kit-ducati-860-900-desmo/?v=6cc98ba2045f

Above is the back up plan option if the large bodied FCRMX carbs dont fit in the confines of the Monster frame. Im confident they will fit in a Supersport frame. The FCR's have accelerator pumps and roller slides, these TM's don't.

[greenmonster]

https://www.mikunioz.com/shop/tm38-twin-mikuni-flatslide-kit-ducati-860-900-desmo/?v=6cc98ba2045f
Nice price!

[koko64]

And our Pacific Peso is weak, good for you guys.

[koko64]

A question. What are the ID measurements for each end of efi manifold rubbers for 695, 696, etc with the regular 45mm throttle bodies? Maybe these can be cut to suit the 48mm OD of the FCR spigots for the front cyl to get the horizontal angle.  I ask remembering that Chris (CCW), once mentioned seeing FCR's fitted to 1000DS manifolds.
I also thought of using automotive 45 deg inlet hose.

[Speeddog]

This critter?

[koko64]

Thanks, yeah . Could I cut it off the alloy section and clamp it to the front cylinder manifold to get close to horizontal? Or even use the TB to airbox rubbers cut down?