Questions about jets and excess oil...

Snakeoil · Post by **Snakeoil** » Wed Apr 06, 2011 8:23 am

MBellRacing wrote:Thanks, since they were only a few euro, I ordered them. None of the part numbers match the ones I found for the original needle for here in the US, figure they'd at least be an interesting experiment.

I too found a "conversion guide" to find a modern Keihin needle that is closest to older models. Anybody have the numbers off their stock set?

Can you share that guide with us here?

thanks,
Rob

brewsky · Post by **brewsky** » Wed Apr 06, 2011 11:07 am

Here's a comparison of the Keyster and Keihin needles for the CA77 (with needle numbers):
The only difference I can detect is the width of the circlip slots.

MBellRacing · Post by **MBellRacing** » Wed Apr 06, 2011 1:35 pm

Brewsky,

I saw the same thing when I looked at my Keyster needle versus the originals. It seems the fallback excuse for my bike's poor running is the Keyster needle and slow jet. I might agree with the latter. I wish I could find my originals.

Look here, only just scanned over the info and haven't seen the original numbers to see if there is a close relative to our CB77 needle.

http://www.motorcyclecarbs.com/KEIHIN_N ... __W252.cfm

teazer · Post by **teazer** » Wed Apr 06, 2011 11:41 pm

If the diameter is identical at 5mm intervals all the way from top to tip, then they are the same. Keyster needles are often quite a bit different at the tip or the root and they need to be absolutely thy same

Very small difference in diameter can make a huge difference to performance.

brewsky · Post by **brewsky** » Thu Apr 07, 2011 4:30 am

MBellRacing wrote:Brewsky,

I saw the same thing when I looked at my Keyster needle versus the originals. It seems the fallback excuse for my bike's poor running is the Keyster needle and slow jet. I might agree with the latter. I wish I could find my originals.

Look here, only just scanned over the info and haven't seen the original numbers to see if there is a close relative to our CB77 needle.

http://www.motorcyclecarbs.com/KEIHIN_N ... __W252.cfm

Notice the needles I posted are for CA77, I believe CB and CL are different part numbers.

I haven't been able to find anything in the charts or diagrams to even match the same overall length.

Also, the conversion chart assumes a 6 digit OEM mark, and the CA needle only has 5

MBellRacing · Post by **MBellRacing** » Thu Apr 07, 2011 8:09 am

Yeah, after looking at that more, I realized there's nothing close to what we have but hoped they had more sections. My brother's CB175 has a similar problem with his Keyster needles versus stock. He can just hold them next to each other and notice the differences!

Snakeoil · Post by **Snakeoil** » Fri Apr 15, 2011 5:54 pm

brewsky wrote:Here's a comparison of the Keyster and Keihin needles for the CA77 (with needle numbers):
The only difference I can detect is the width of the circlip slots.

Brewsky,

Thanks again for posting those pics. Today I tried to solve a problem and I was afraid I had a pair of Keyster needles in my carbs. But based on your pics, they are Keihin needles. Circlip slot width and the steps just above the straight section match what I have.

No numbers on mine, though. Bike is a '67 CL77.

regards,
Rob