Idle

[Wayne1960]

Can anyone explain how to adjust the throttle and carbs so that the bike will idle at the specified revs.
At the moment when I let go of the throttle the motor cuts out.
The screw on the carb body doesn't touch the throttle wheel on the carbs yet so I'm guessing the cables need adjusting to pul on the wheel to keep the revs up.

[weaver]

the screw should be adjusted to lift the wheel off its stop to give an idle,if the throttle cables were used there would be no slack in the cables and it would give a poor action and the revs would probably rise when the handlebars are turned side to side

[zed1015]

Slacken off all throttle cables.
Screw in the idle screw until it touches the throttle wheel.
Start the bike and adjust the screw so the engine idles at around 1000 revs.
Carefully adjust out the slack on the opening pull cable and then the same on the closing cable.
Leave a tiny amount of slack so the cables aren't pulling against each other.
Snap the throttle a couple of time to settle everything then re-adjust the idle to 1000rpm when warmed up.

[Wayne1960]

I'm wandering if I have the wrong spring on the idle screw. When it is screwed in tight the screw end doesn't reach the throttle wheel to start with. The spring measures about 10mm when fully compressed!

[weaver]

is the throttle closing fully? if not it wont reach the screw,the throttle cables could be too short,routed wrongly or maladjusted

[steve bowdler]

Are all your cables slack as was mentioned earlier any pics ?

[cheeme]

Wayne - Its worth checking the inside of the throttle bodies to make sure the butterflies are closing fully. I had a similar sounding issue with mine - adjuster not making contact, although mine was suffering from high revs. There was a slight buildup of 'black stuff' on inside which was enough to stop the butterflies closing and therefore the lever never got to its full resting point. I cleaned them out with some wire wool and a through good blast of air to make sure there were no nasty bits of wire left behind.

[Wayne1960]

Ok I'll have a look. The throttle and cables fell really good and when I let the throttle go it returns and stops positively. The cables have not been adjusted really they are on there up tight settings. The throttle wheel rotates and stops positively. Without the spring it reaches fine.

[Pigford]

[quote="cheeme"]Wayne - Its worth checking the inside of the throttle bodies to make sure the butterflies are closing fully.[/quote

They're proper "slide" carbs on a Z900 - not CV

[Wayne1960]

Ok throttle bodies?????? You mean the throttle on the handlebars?

[z1bman]

its a z900 a4 & has carbs.as i have already mentioned the problem is the slide height adjustment. the slides are sitting too low in the carb body

[weaver]

think someone needs to pop round and eyeball the bike to iron out the problems

[Wayne1960]

It's ok I'll get there. Got new points coming tomorrow so change them over.
I understand what you mean by slides and I didn't adjust them because they were exactly how they said in the manual, I think!
The last bike I had was when I was 17, I'm now 54 and a little rusty. I have however just built it from scratch, with a little help from my friends on here!
Just checked the cables and they feel ok and took the throttle apart and it looks ok.

[Wayne1960]

I think I have the cables connected wrong on the throttle wheel at the carbs. Does anyone have a good picture showing the cables connected to the wheel with the locking nuts?

[zed1015]

Those lock nuts do not go together.
One of the nuts need to be on the underside of the bracket and the other above so that they sandwich the bracket.
The bottom one is prevented from turning by a small protrusion on the bracket.