idles really high. Can't even adjust black idle knob to resolve it

If it's broken or just needs tweaked

Moderators: Volker_P, tidd650

juntjoo
Posts: 243
Joined: Fri Nov 10, 2017 6:19 pm

idles really high. Can't even adjust black idle knob to resolve it

Postby juntjoo » Mon Feb 19, 2018 6:10 am

https://youtu.be/p2pvEqy3Evc

pilot screws and idle knob made no effect. no leaks. hmm. but getting close!
82" cb650 Nighthawk

User avatar
GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby GeorgeSweety » Mon Feb 19, 2018 6:46 am

Does it rev higher when you switch the choke off? it appears that way in the vid but I'm unsure of the choke lever operation on the Nighthawk.
Is the choke cable connected correctly?
Is the air filter in and the cover on?
What happens if you give it some throttle?
Have you removed a plug to see what colour it is?
Any change in revs if you turn the handlebars? (tight or trapped cables)
Just a few thoughts at the moment :roll:

juntjoo
Posts: 243
Joined: Fri Nov 10, 2017 6:19 pm

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby juntjoo » Mon Feb 19, 2018 4:17 pm

GeorgeSweety wrote:Does it rev higher when you switch the choke off? it appears that way in the vid but I'm unsure of the choke lever operation on the Nighthawk.
Is the choke cable connected correctly?
Is the air filter in and the cover on?
What happens if you give it some throttle?
Have you removed a plug to see what colour it is?
Any change in revs if you turn the handlebars? (tight or trapped cables)
Just a few thoughts at the moment :roll:


No it revs higher as I close the choke, activate it. As far as I've been able to tell I installed it correctly and it functions properly. I'll do that handlebar test then one bowl at a time I'll take the cover off and hold the float up with a finger while adding gas then test to find the point, if any that the float needle stops the flow of gas. Good idea? I'll assume so and report back
82" cb650 Nighthawk

User avatar
GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby GeorgeSweety » Mon Feb 19, 2018 4:23 pm

jj, I wouldn't go taking anything off at the moment, just check everything that I mentioned first, like is your air filter and cover installed?

juntjoo
Posts: 243
Joined: Fri Nov 10, 2017 6:19 pm

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby juntjoo » Mon Feb 19, 2018 5:37 pm

GeorgeSweety wrote:jj, I wouldn't go taking anything off at the moment, just check everything that I mentioned first, like is your air filter and cover installed?


yeah, thats on. I'm not talking about taking the carbs out, just the bowl covers one by one, obviously as I've only got two hands
82" cb650 Nighthawk

User avatar
Folsoml
Posts: 1600
Joined: Sat Apr 07, 2012 9:02 pm
Location: North Florida

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby Folsoml » Mon Feb 19, 2018 7:47 pm

I'm not sure I understand your answer to George's question about the choke lever. I'm not familiar with the Nighthawk choke lever either. Is the high idle when the choke is closed or open?
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

juntjoo
Posts: 243
Joined: Fri Nov 10, 2017 6:19 pm

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby juntjoo » Mon Feb 19, 2018 8:49 pm

Folsoml wrote:I'm not sure I understand your answer to George's question about the choke lever. I'm not familiar with the Nighthawk choke lever either. Is the high idle when the choke is closed or open?


Closed. The position I've been putting it in to start the bike. I know, confusing. We close it to use it. Open, not in use it'll go as low as 1.5krpms and that's my starting point to this issue.
82" cb650 Nighthawk

User avatar
GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby GeorgeSweety » Tue Feb 20, 2018 5:42 am

jj, just been in my shed to check my choke. This is the position with the choke off.
choke lever position 001.JPG
choke lever position 001.JPG (135.89 KiB) Viewed 756 times

User avatar
GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby GeorgeSweety » Tue Feb 20, 2018 5:44 am

And this is the on position.
choke lever position 002.JPG
choke lever position 002.JPG (143.98 KiB) Viewed 756 times
It would appear that your bike was revving higher because you were putting your choke on.

User avatar
GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby GeorgeSweety » Tue Feb 20, 2018 5:49 am

And this is when I cry like a baby cos my little baby Nighthawk is all busted and I ain't got time to fix her yet :cry: :cry: :cry:
choke lever position 003.JPG
choke lever position 003.JPG (149.86 KiB) Viewed 756 times

User avatar
Folsoml
Posts: 1600
Joined: Sat Apr 07, 2012 9:02 pm
Location: North Florida

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby Folsoml » Tue Feb 20, 2018 6:03 am

GeorgeSweety wrote:And this is when I cry like a baby cos my little baby Nighthawk is all busted and I ain't got time to fix her yet :cry: :cry: :cry:


:lol: :lol: :lol:

juntjoo wrote:
Folsoml wrote:I'm not sure I understand your answer to George's question about the choke lever. I'm not familiar with the Nighthawk choke lever either. Is the high idle when the choke is closed or open?


Closed. The position I've been putting it in to start the bike. I know, confusing. We close it to use it. Open, not in use it'll go as low as 1.5krpms and that's my starting point to this issue.


I would do like George suggested and check the throttle cable to make sure it's not too tight.
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

User avatar
GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby GeorgeSweety » Tue Feb 20, 2018 6:29 am

When I first bought my Custom the PO had put cables on from a CB650Z which is the road version in the UK, they have straight flat bars on them, hence cables way too short :roll:

juntjoo
Posts: 243
Joined: Fri Nov 10, 2017 6:19 pm

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby juntjoo » Tue Feb 20, 2018 6:37 am

You have my bike! Is that the 650? Take her back out and fix her up and we can be best friends! Well, we can see...

Just about to get working on mine. Yeah I'll just loosen the throttle cable. I could be reading it wrong. Man I can wait till they make these out of transparent metals. I think I just saw something on clear aluminum. 'well no wonder my bike won't start as clearly I have a frog stuck in there'.
82" cb650 Nighthawk

juntjoo
Posts: 243
Joined: Fri Nov 10, 2017 6:19 pm

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby juntjoo » Tue Feb 20, 2018 7:31 am

hmm... when I adjust the cable nothing happens really till I fully back out the nut, then it's too loose. previously it had been turned in all the way down. I not sure if I'm measuring this 1/8 if free play right as there is always a little wiggle in the cable before it pulls the lever. that's probably it and I'm good. And I'll back out the nut a little just to be towards the middle of this range where it functions consistently throughout. if anything the other cable could use some tightening as it appears to sorta lag on the throttle cable's return to default pos. but the lever spring seems to do its job to bring lever back just fine so maybe that's perfectly normal, a slight delay /lag on the return to default position. and it doesn't appear to have a way to adjust it anyway

then move on to floats check. i think I'll video some of that...
82" cb650 Nighthawk

juntjoo
Posts: 243
Joined: Fri Nov 10, 2017 6:19 pm

Re: idles really high. Can't even adjust black idle knob to resolve it

Postby juntjoo » Tue Feb 20, 2018 9:34 am

https://youtu.be/iBDXlXw0hLE

overflow into vent line
82" cb650 Nighthawk


Return to “Technical Discussion”

Who is online

Users browsing this forum: No registered users and 6 guests