Twin JRC carb field report

Great report.

Yours is a 750, correct? I'm guessing from your earlier posts on the 930 head banging.

Has anyone tried these successfully on an 850? I'm weary of the vague metering of my Amals in the 2500 to 3000 mid range, but love the top end too much to go back to the mikuni.
Would the 30mm be to small for an 850?

I wouldn't use 30mm carbs on an 850 - especially if you want top end. And you are correct in noting that Mikunis are too restrictive. The 32mm PWK flat slides are the best of everything. Rolling on the throttle is like dialing up a rheostat of an electric motor - smooth and linear.

I wouldn't put 30m carbs on a 750 either. The 32s work perfectly in idle and mid range - so why not have a little extra throttle available when you need it for passing & pulling on the freeway etc. Flat slide carbs are so much more efficient that you can use a larger size without making sacrifices. Plus the 32s come rubber mounted. The 30s do not.

Another thing about these carbs is that they don't rattle like some flat slides because one surface has a slight curve to avoid that problem. And they fit parallel like the original Amals - not splayed out to the sides like some oversized Mikunis.

Finally got around to snapping some photos of the JRC's installed...




and one of my new wheels for good measure!

For your 30mm carbs

Are they running clean from idle to redline?
main & idle jet size?
needle position?
does the needle come to a point or is it a Norton specific needle ( about 1/16 diameber at tip).
Jim

jseng1 said:

For your 30mm carbs

Are they running clean from idle to redline?
main & idle jet size?
needle position?
does the needle come to a point or is it a Norton specific needle ( about 1/16 diameber at tip).
Jim

Click to expand...

She runs great at all openings except idle is still a bit dodgy and erratic, trying a few things with that.

Main = 122
Pilot = can't determine, not stamped
needle position = second from top
needle tip = not sure