Inlet upgrade?

Question…..
Was anyone able to source that round K&N filter element from the Kuryakin 9872 assembly? If not, are there any dimensions on the element? A person might be able to find an element off the K&N website?
Thanks
Shayne
 
Question…..
Was anyone able to source that round K&N filter element from the Kuryakin 9872 assembly? If not, are there any dimensions on the element? A person might be able to find an element off the K&N website?
Thanks
Shayne
Hello Charlotte , I am not sure what filter element you are referring to ? Is this a OEM air filter replacement for the stock air box ? I would use the BMC or BCM Made in Italy filter if I was replacing a mine. If you do a search you will find it on this site.
 
I think @Charlotte is referring to the filter in this thread..

 
I think @Charlotte is referring to the filter in this thread..

Thanks Cliffa , I remember now.
 
Yes…… that was the air cleaner/filter I was wondering about.
Ps… I still haven’t found the air filter element yet……
 
Happy New year!!

Well folks, here is my connotation on an inlet upgrade. It has been mentioned in the past that there is no provision to balance the Jenvey throttle bodies, and I have always wondered if a lot of the mechanical chatter is a result of them being out of balance. I have a spare throttle body which I use to test fit every one of my throttle body covers. (see here for more details). And whilst making them I kept looking and looking at it and wondering, then eventually bit the bullet and picked up the hacksaw. This is the result...


Screenshot 2026-01-01 211350.jpg
Screenshot 2026-01-01 211518.jpg
Screenshot 2026-01-01 211600.jpg



Whether it will be worth all the effort remains to be seen, but I enjoyed doing it!

if you want to see how I did it, you can view the whole process here
 
Last edited:
I do wonder what hitherto well hidden foibles would be unmasked if the 961 was tuned for more oomph...?
Most motorcycle manufacturers probably prefer that people are not killed by their products. My 850 motor is absurd - simply because of its hidden potential. I chose one carburetor size and ignition timing and exhaust system and worked with it. I think cams and compression ratio are pretty much irrelevant. Balance and optimisation probably pretty much always achieve the same result. The worst thing is mindset - we all probably tend to be defeatist. With engines and machine handling, it is always frustrating when a calculated adjustment causes almost zero change in performance.
 
Last edited:
When people replace their carburetors and get better performance, do they ever try to discover the reason for the improvement? I would have both the old and the new carburetors in pieces - looking for the reason. My brother has a jeweller friend who can actually measure the internal diameter of a needle jet. It was really funny - he had two speedway sidecars which were identical except one had an H1 Kawasaki motor, and the other one had an H2 Kawasaki motor - both were on methanol. The one with the H2 motor was too fast and dangerous. The bike with the H1 motor was fast enough to win any sidecar race. In about 2001, he was Australian Long Track Champion using the bike with the smaller motor. The bike with the bigger motor was simply frightful. When it came on song, it could easily jump 4 metres ahead in an instant. He became a bit smarter after he had a big crash with it. He would not like me revealing the reason his bikes are fast. Most people buy needle jets off the shelf and just use them. With methanol as fuel, needle jet size is critical - with petrol as fuel, needle jet size is twice as critical. I would use a flow metre and a bottle of gas and reamers for calibration purposes. The taper on the needles makes a significant difference.
 
Last edited:
Back
Top