JS motorsports CR carbs

koda · Mar 8, 2015

Is anyone using the new Keihin CR carb setup that Jim is offering. I would love to hear some input. I have had a set of 37's on one of my Z1s for years .

jseng1 · Mar 8, 2015

Only a couple sets have gone out - they are a new product. So you won't get any feedback yet. "Matchless" motivated me when he set up a pair of his own and helped me with some ideas and plans for this project. They require some parts to be fabricated and installed.

koda · Mar 8, 2015

well they certainly look like the right stuff. very tidy fabrication work.

motoalchemist · Mar 9, 2015

Yes, I have a set of older units on my fastback Im building....but I havet run them yet...so will advise when I get it running. But I hear they are the awsome.

acotrel · Mar 9, 2015

There are a lot of good things on that bike.

madass140 · Mar 10, 2015

very observant Al, probably even better bits inside.
I have a set of the 33's as well for a current project but it will probably be much later in the year before they suck air.
probably in 12 mths we should all be getting a good idea on setting these up. I reckon its gonna be worth it.

commando6868 · Mar 10, 2015

jseng1 said:
Only a couple sets have gone out - they are a new product. So you won't get any feedback yet. "Matchless" motivated me when he set up a pair of his own and helped me with some ideas and plans for this project. They require some parts to be fabricated and installed.

What advantage do these carbs offer?

MF

Matchless · Mar 10, 2015

The CRs make the bike lighter. This weight saving is due to the wallet in the pocket of your Barbour being lighter!!
I fitted the 33mm CRs to my 920 last year & spent a while on the Dyno. setting them up. I haven't done many miles on it since then, but it certainly seemed to go well enough on the 45 mile ride back. The good points would be build quality, easy to obtain parts at fairly reasonable prices, & the fact that they are locked together on a common throttle linkage so should stay in tune. In all fairness to the Amals, it did go very well with those too.
The bike will be back in action on the 1st of April because being 40 years old the road tax will be free (only bloody thing in this country that is) I will report back then.

Martyn.

jseng1 · Mar 12, 2015

motoalchemist said:
Yes, I have a set of older units on my fastback Im building....but I havet run them yet...so will advise when I get it running. But I hear they are the awsome.

What do you do about the original cable bracket -doesn't it interfere with the tank? And what kind of manifolds are those.?

mdt-son · Mar 25, 2018

jseng1 said:
Only a couple sets have gone out - they are a new product. So you won't get any feedback yet. "Matchless" motivated me when he set up a pair of his own and helped me with some ideas and plans for this project. They require some parts to be fabricated and installed.

Hi Jim,
I realize this thread is getting old. The CRS carbs are no longer listed in your web shop. Too little consumer iterest or due to a techncal problem?

-Knut

jug · Mar 26, 2018

motoalchemist said:
Yes, I have a set of older units on my fastback Im building....but I havet run them yet...so will advise when I get it running. But I hear they are the awsome.

Man, this thing looks like it's doing 100 mph and its still on the bench. Love it....
BTW, I got a set from Jim a while back for my re-build. When I saw they had gone from his web site I inquired as to why, Jim said his supplier pricing was the issue.
jug

jseng1 · Mar 26, 2018

jug said:
Man, this thing looks like it's doing 100 mph and its still on the bench. Love it....
BTW, I got a set from Jim a while back for my re-build. When I saw they had gone from his web site I inquired as to why Jim, said his supplier pricing was the issue.
jug

That and my work load which is too heavy right now. The smoothbore carb kits require modification, disassembly and fabrication of parts to prepare. Maybe I'll pick them up again at a later time.

Beaneater · Apr 1, 2018

I got the carbs from Jim. They kick ass and I'm very glad that I bought them.

jug · Apr 1, 2018

Yep, real nice setup.

BTW Jim, can you still supply the shorter intake rubbers if they are needed?
Sorry to hijack.
jug

jseng1 · Apr 2, 2018

Yes I will support all parts for them (as well as the PWKs). I'm surprised how many people still ask for them, I'm hoping but I can't promise I'll re-issue them.

chrisshropshire · Apr 3, 2018

I was hoping you would start making them again , I will keep a lookout

Beaneater · Apr 3, 2018

Is there a benefit to the shorter intake rubbers? I'm curious. Thanks

jseng1 · Apr 4, 2018

Beaneater said:
Is there a benefit to the shorter intake rubbers? I'm curious. Thanks

The short boots and manifolds are necessary to keep the carbs from backing into the frame. All aftermarket twin carbs are bigger than the Amals. There is no other benefit from being short other than to give necessary clearance.

Beaneater · Apr 4, 2018

jseng1 said:
The short boots and manifolds are necessary to keep the carbs from backing into the frame. All aftermarket twin carbs are bigger than the Amals. There is no other benefit from being short other than to give necessary clearance.

Does that mean the boots that came with the carbs from you are the short ones? Thanks again

JS motorsports CR carbs

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