JS Motorsports Carbs

Schwany · Oct 24, 2020

50mm O.D. on the air filter end of the carburetors.

Jim sells a K&N ham can filter for the kit separately. I would imagine the ham can is not as good at higher RPM as velocity stacks or short cone style filters, but the carburetors could be tuned well enough to make a street bike rider happy with a ham can.

As far as getting clean air into the engine, none of the oil soaked gauze filters are really worth a damn in my experience. An ugly foam UNI filter does a better job. The stock box probably better yet, if it uses a paper filter.

Unless Jim has the CRS carburetors stock piled, there aren't any available from Keihin until late November 2020. Source for that information is Sudco USA.

jseng1 · Oct 24, 2020

Schwany said:
50mm O.D. on the air filter end of the carburetors.

Jim sells a K&N ham can filter for the kit separately. I would imagine the ham can is not as good at higher RPM as velocity stacks or short cone style filters, but the carburetors could be tuned well enough to make a street bike rider happy with a ham can.

As far as getting clean air into the engine, none of the oil soaked gauze filters are really worth a damn in my experience. An ugly foam UNI filter does a better job. The stock box probably better yet, if it uses a paper filter.

Unless Jim has the CRS carburetors stock piled, there aren't any available from Keihin until late November 2020. Source for that information is Sudco USA.

I think the K&N ham can breathes better than the short cone filters because there is more area and only one cylinder is pulling air at a time so each cylinder is effectively pulling through a larger air cleaner. I think this has been tested and verified on this forum before.

Schwany · Oct 24, 2020

jseng1 said:
I think the K&N ham can breathes better than the short cone filters because there is more area and only one cylinder is pulling air at a time so each cylinder is effectively pulling through a larger air cleaner. I think this has been tested and verified on this forum before.

I'll buy that science.

I had the 3 inch deep K&N ham can on the 930 Amals in the 70's. It worked. I had UNI foam filters on the Mikuni carburetors initially, but they didn't flow air as well as the cheap little gauze cones I'm using now. However the cones I have right now don't filter fine particles at all. I'm sure what you are selling works great, didn't mean to come off like it doesn't at all.