Hanging onto revs

[tevan]

Sneck,

What did you find on your problem. I read what all the things it could be but not what the problem was. Have you had the time to track it down?

[NobleHops]

Sneck,

What did you find on your problem. I read what all the things it could be but not what the problem was. Have you had the time to track it down?

Am equally interested...

N.

[sneck]

Sneck,

What did you find on your problem. I read what all the things it could be but not what the problem was. Have you had the time to track it down?

Adjusted the idle screws which wasn't easy with carbs fitted to 2.5 turns out, it idles better but not perfect I am looking into synching the carbs with a set of gauges.

I had a ride out today and it rides and runs ok, but has a lumpy ( tickover - English dictonary) idle speed -ie 1000rpm

Just out of interest are the idle screws - fuel screws or air screws, the reason I ask is to determine whether turning the screws out richens or weakens the mixture?

Sneck

[spencer]

Just out of interest are the idle screws - fuel screws or air screws, the reason I ask is to determine whether turning the screws out richens or weakens the mixture? Sneck

They are fuel screws. Turn them out and you richen the mixture.

[sneck]

They are fuel screws. Turn them out and you richen the mixture.

Thanks that's what I wanted to know.

I must say you guys have been a huge help on this forum its like having there by my side BIG THANKS

Sneck

[oldschoolcarbs]

Not to suggest that this is what you have going on but I'll toss it out there for consideration.

Have a look at the photo. You'll notice that the throttle isn't closing all the way even though it's separated from the rack AND under spring load. The problem is NOT due to lacquer in the bushings but from the plate binding slightly against the inner bore.

I virtually never find a set where I don't have to address this on at least one of the bodies. Sometimes it's only a teeny bit off and will slowly close under vibration, other times you can't force it closed no matter what you do. The solution is very simple but it can only be done with the carbs separated, else interference from the synch screws will prevent a perfect result. All you need to do is loosen both butterfly screws just a tad and the plate will right itself. They're actually designed such that there's quite a bit of free play for this reason.

What it'll cause is a slow return to idle, or a permanently high idle if the binding is bad enough to overcome the spring pressure. The aggravating part is that you can't compensate by adjusting the synch.

We take care of this as a matter of course but it's very easy to miss if you don't inspect each body carefully before joining them.

[sneck]

Thanks oIdschoolcarbs

I have got the carbs off again so I will have a look and check the position the plates

Thanks Sneck

[6Pipes]

Not to suggest that this is what you have going on but I'll toss it out there for consideration.

Have a look at the photo. You'll notice that the throttle isn't closing all the way even though it's separated from the rack AND under spring load. The problem is NOT due to lacquer in the bushings but from the plate binding slightly against the inner bore.

I virtually never find a set where I don't have to address this on at least one of the bodies. Sometimes it's only a teeny bit off and will slowly close under vibration, other times you can't force it closed no matter what you do. The solution is very simple but it can only be done with the carbs separated, else interference from the synch screws will prevent a perfect result. All you need to do is loosen both butterfly screws just a tad and the plate will right itself. They're actually designed such that there's quite a bit of free play for this reason.

What it'll cause is a slow return to idle, or a permanently high idle if the binding is bad enough to overcome the spring pressure. The aggravating part is that you can't compensate by adjusting the synch.

We take care of this as a matter of course but it's very easy to miss if you don't inspect each body carefully before joining them.

Just a quick question here. Are the screws staked from the back side? If not, and they are loosened to adjust the plate, I assume that locktite is in order for the tightening procedure? Scary to think what one of those screws would do to the engine if it came loose

[daves79x]

Yes, they are staked, but will loosen enough to center the plates. That is a good point Oldschool brings up. I've seen it a couple of times as well. It becomes pretty obvious if you have them separated and each individual butterfly does not 'snap' shut. I didn't review the whole thread, but I'd still bet on a low-speed jetting issue - not completely clean, or a badly out-of-sync rack. With them off, you can visually bench-sync them very very close to perfect, assuming good cylinder health. As for the idle circuits, I'd check them again.

Dave

[sneck]

Can you elaborate on the bench sync. please. Dave

Sneck

[NobleHops]

Sneck, try the search box upper right. You will be amazed at how much stuff it turns up .

N.

[sneck]

Doh

Sneck

[79cbx]

[sneck]

Hi All

Just to give you a bit of an update, I had the carbs synced by a UK CBX club member ( which wasn't an easy job due to number 3 adjuster being stuck ) I couldn't believe the difference as they all became balanced the engine sounded sweeter, smoother, and more responsive.
It was a joy to ride it back home and a totally different bike to ride compared to before they were synced. On the 20 mile ride back home I had to stop and slow the("Tickover" English Dictonary ) idle speed down twice to roughly 1000rpm which has now settled down to this


Thanks to all who have helped me get my CBX back up and running






Sneck

[steve murdoch icoa #5322]

Ain't it great when a plan comes together!
Sneck, what pipe is that and when can we expect to hear it? lol.