Idle Settting

Slow but steadyh 'mworking through the problems with this bike. [79 kz1000 ]

It runs prety good now but has one aggravating problem.
after i've ridden it for awhile 20-30 minutes the idle jumps way up to around 2000 rpms (don't have a tach)if i manually push on the linkage it goes down to normal (100 maybe). While looking into this i noticed that the idle screw is not in contact with the linkage so i know it can't be right.

anyone have any idea why it would do this??

The hell of it is that it idles kind of good aside freom its little quirk. i can also get it to step down if i snap the throttle open and closed.

Sound like a sticky throttle cable to me? Disconnect the cable at the carb and grip ends, hang it up from one end so it's vertical and spray WD40 down between the actual cable and it's outer covering until it runs freely out the lower end. Mop up the mess you've now made on the livingroom carpet. Refit & adjust.

MBFMGP wrote:

Slow but steadyh 'mworking through the problems with this bike. [79 kz1000 ]

It runs prety good now but has one aggravating problem.
after i've ridden it for awhile 20-30 minutes the idle jumps way up to around 2000 rpms (don't have a tach)if i manually push on the linkage it goes down to normal (100 maybe). While looking into this i noticed that the idle screw is not in contact with the linkage so i know it can't be right.

anyone have any idea why it would do this??

The hell of it is that it idles kind of good aside freom its little quirk. i can also get it to step down if i snap the throttle open and closed.

I was having that problem just today and found that the intake boots were leaking(screws loosened up)and was sucking air,An easy way to check for this problem is spray carb cleaner around the intake boots and if the RPMS go up there is a leak.

Thnks guys I'lll try both things tomorrow,,,,,,,,,,,

happy easter

Make sure the proper spring is on the return. If someone messed with the sinc of the slides (if they are mechanically connected), it will bind.

The last person to synchronize the carburetors didn't do the job properly. Synchronization MUST occur where the idle stop screw is pretty much in the center of its operating range. Then you adjust slide height (bench sync) and then sync with a manometer. This person just started sync using a manometer BUT the idle stop screw was on the EDGE of its adjustment. When the carbs were sync'd the idle stop screw is no longer in the center of its operating range but on the edge so that when you try and back down the idle; like after the engine is warmed, you have no adjustment since the screw is not contacting the stop.

When you push down on sync arms, the idle will drop because you are forcing the slides down. This means little as it will happen on a properly tuned bike as well. Resynchronize the carburetors properly and first bench sync. There may be another reason the idle doesn't return as well... no slack in throttle cable, poor seal around mixture screw gasket, leak around or in rubber manifold or perhaps a leak in a vacuum cap.