Choke not working after needle position moved

[IronJimCb]

Hi guys

Since adjusting my needle height on my cb400f the choke has stopped working. When I now have the choke on from cold starts it does nothing in fact it works the opposite when it's on the bike won't start and when it's off the bike will start but I have to give it a few goods kicks to get it going from a cold start. Any shed some light on why it's doing this? Have I adjusted something I shouldn't of ?

Thanks

If you've never owned one you'll never understand

CB400F

[Nurse Julie]

Did it start ok with the choke before moving the needles? And, I'm sure you are a very experienced 400/4 owner but are you sure you are putting the choke lever  in the correct position for ON/OFF, the arrow on the lever can be somewhat confusing (Don't ask me how I know that !!!!)

[IronJimCb]

Did it start ok with the choke before moving the needles? And, I'm sure you are a very experienced 400/4 owner but are you sure you are putting the choke lever  in the correct position for ON/OFF, the arrow on the lever can be somewhat confusing (Don't ask me how I know that !!!!)

Yep it worked perfect before hand when the choke is on its In the up position towards the sky. when the choke is off its down towards the ground....I think lol

If you've never owned one you'll never understand

CB400F

[Chris400F]

I was getting confused, had to go and look at the bike ....
In the up position the choke flaps are closed, in the down position they are open.
I'm guessing by 'On' you mean when the flaps are closed, I am more familiar with 'Open' or 'Closed' terminology but maybe that's just me!
Anyway, before this, I was going to suggest that you check the choke flaps are actually doing what you expect.
I know this means at least partially removing the airbox, but it shouldn't take long to get to a point where you can see the movement of the choke flaps.
At least that would prove that part is working as it should.

[IronJimCb]

If the choke is on the slides are closed to reduce air and increase fuel ? If the choke is off then the slides are open to let the air through? 

If you've never owned one you'll never understand

CB400F

[IronJimCb]

Chris I'm running pods so it's not so bad

If you've never owned one you'll never understand

CB400F

[Bodd]

This should clear things up 

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[IronJimCb]

Thanks bodd I am definitely using it correctly . Still have the issue and it's annoying as hell.

If you've never owned one you'll never understand

CB400F

[Bodd]

Have you re jetted for the pod filters  ? When I got velocity stacks the bike started and idled better with #38 slow jets, I also couldn't get them balanced properly with #40.

[IronJimCb]

Same. I'm running k&n pods and my jetting setup currently is #38 pilot and #100 main. No change to the needle position.

If you've never owned one you'll never understand

CB400F

[andut]

Jim (?)

Have you adjusted idle speed screw to compensate anywhere along the line ?  If you have, then there's a good chance that will have changed the 'fast idle' setting on the choke mechanism, and that maybe affecting your choke operation / warm up procedure.  Worth checking to see if the cam on the choke lever (other side of the lever's pivot point at the top of #1 carb) is actually touching / moving the main throttle spindle.

Would you mind telling me where you got your 38 idle jets please ?  I'd be interested to try them on my 400 !

Andy

[Greg65]

Air leakage can generate some very funny symptoms. Have the O rings on the manifold rubbers been inspected, replaced? They do dry out, crack and weaken the mixture. Getting them off can be entertaining, when you replace them consider using stainless steel fittings with anti sieze compound if you are not too purest. Hope this helps.

Greg

[IronJimCb]

Jim (?)

Have you adjusted idle speed screw to compensate anywhere along the line ?  If you have, then there's a good chance that will have changed the 'fast idle' setting on the choke mechanism, and that maybe affecting your choke operation / warm up procedure.  Worth checking to see if the cam on the choke lever (other side of the lever's pivot point at the top of #1 carb) is actually touching / moving the main throttle spindle.

Would you mind telling me where you got your 38 idle jets please ?  I'd be interested to try them on my 400 !

Andy

Hey great advise btw I'll check it when I get home I was thinking it may be something like that. I got the 38's from 4into1 but there not factory made they are aftermarket but they seem to do the job well enough. I tried getting them from jets r us but they don't ship to the UK anymore

If you've never owned one you'll never understand

CB400F