Author Topic: Cb 750k2 Carb needles  (Read 3485 times)

Offline Pauarc

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Cb 750k2 Carb needles
« on: September 27, 2024, 11:00:30 AM »
Have just been cleaning the carbs on my cb750k2 I have noticed that the needles and seat look different see pictures could this make it run uneven clip is middle position so as you see, they’re not sitting in the same they are only just lightly pushed on
Honda 90ss, Cb250k1 supper sport,
Cb400 four, CB750k7, Cb550, Cb750f2n,
Cb750k2

Offline McCabe-Thiele (Ted)

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Re: Cb 750k2 Carb needles
« Reply #1 on: September 27, 2024, 11:46:19 AM »
Are there any markings visible on the needles or jets?
The top one looks the odd one out.
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Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
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Re: Cb 750k2 Carb needles
« Reply #2 on: September 27, 2024, 12:13:16 PM »
Those are the needle guides and needles. As long as the needles and the guides are all the same, it won't affect the running. The top one doesn't look the same as the others.
« Last Edit: September 27, 2024, 12:15:59 PM by Nurse Julie »
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Offline Pauarc

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Re: Cb 750k2 Carb needles
« Reply #3 on: September 27, 2024, 12:32:20 PM »
They are all marked k2720
Honda 90ss, Cb250k1 supper sport,
Cb400 four, CB750k7, Cb550, Cb750f2n,
Cb750k2

Offline Pauarc

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Re: Cb 750k2 Carb needles
« Reply #4 on: September 27, 2024, 01:13:56 PM »
The top needle was from no 1 which allways had a slight mis at idel
Honda 90ss, Cb250k1 supper sport,
Cb400 four, CB750k7, Cb550, Cb750f2n,
Cb750k2

Offline Skoti

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Re: Cb 750k2 Carb needles
« Reply #5 on: September 27, 2024, 01:32:12 PM »
If they've done more than 15k then they are probably worn out.

I've done 55k on my CB750F1 and I'm on my 3rd set of needle jet kits.

Most folk ignore them but when you renew them the difference in starting, performance and fuel consumption is very noticeable.

Apparently some after market replacements have incorrect needle profiles and cause a flat spot when accelerating, I use only genuine Honda ones.
 

Good luck

Skoti



Oh, BTW.

an easy way to tell if they're worn out is, if the needle (with the clip removed) can pass all the way through the needle jet unhindered then they're buggered.

You can't do that with new ones.
 
« Last Edit: September 27, 2024, 01:40:25 PM by Skoti »
Skoti


Motorcycling is Life, anything B4 or after is just waiting...

1976 Honda CB750F1

Offline Pauarc

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Re: Cb 750k2 Carb needles
« Reply #6 on: September 28, 2024, 05:51:23 PM »
After cleaning needles and jets it looks like the jets are worn looks like they need replacing no 1 is worn the worst
Honda 90ss, Cb250k1 supper sport,
Cb400 four, CB750k7, Cb550, Cb750f2n,
Cb750k2

Offline Pauarc

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Re: Cb 750k2 Carb needles
« Reply #7 on: November 04, 2024, 11:22:50 AM »
New needles and jet run better and tic over smoother about 1000 rev and sync much better all around 21hg
Honda 90ss, Cb250k1 supper sport,
Cb400 four, CB750k7, Cb550, Cb750f2n,
Cb750k2

Offline Martin6

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Re: Cb 750k2 Carb needles
« Reply #8 on: November 05, 2024, 08:45:18 AM »
I'm thinking of doing the same, before too long. Where did you get the new needles / jets from?

Offline Skoti

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Re: Cb 750k2 Carb needles
« Reply #9 on: November 05, 2024, 09:24:02 AM »
Look up the part number on CMSNL and then order and pick them up from your local Honda dealer.

Or online from DS or Fowlers of Bristol.




Skoti


Motorcycling is Life, anything B4 or after is just waiting...

1976 Honda CB750F1

 

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