Idle rises while on side stand!?

My husband has recently cleaned and refitted the t-fittings and carbs in my 76 KZ900. There has previously been a gas leak or two from those fittings. Afterward I have ridden the bike-no problem, beautiful response. After a few hundred miles I am noticing that the idle rises while on the side stand-lowers after uprighting the bike after warming up. What could be the problem?

First thing I'd look at is whether the throttle cable is being pulled (i.e. pinched when the handlebars turn.)

I thought of that but the idle changes without moving the handlebars just goes up when on sidestand and lowers when uprighting or leaning to right. Seems like a fuel feed problem. I have a gravity fed system.

In order for the idle speed to rise, the slides have to open a tad... more vacuum is created and this draws more air/fuel. This is most likely a cable thing as opposed to a fuel flow issue. Check cable routing as already mentioned... also... bend down and take a look where the cable goes into the cable holder bracket on your carb assembly. You should see some VISIBLE SLACK in each cable. If the cable is straight or taut, it can cause the slides to open slightly if the cable has ANY bind to it. To put some slack in the cables if there is none, just loosen the locknuts on the barrel adjusters up on the switchgear (where the throttle is) and turn the barrels towards you as you sit on the bike. This puts slack in the cable.

Well, after over 6 months, that's right 6 MONTHS, of fiddling with the 900 and reading numerous posts we finally fixed the problem in about 30 seconds.

I asked my hubby to show me where the choke plunger was located and he proceeded to show and explain that each carb has a plunger and demonstrated how they went up and down with the choke lever while watching the easy to see 3rd and 4th plunger on the drivers right. I noticed they moved together up and all the way down. When I went to look at the almost hidden 1st and 2nd neither one closed completely. He removed the tank and adjusted the screw to each so the plungers lined up evenly and Voila! no more mysterious idle elevation. Just a beautifully smooth ride!

Unfortunately, there's no way of knowing if all the electronic replacements-not to mention many gas-fouled spark plugs, could have been avoided by this extremely simple adjustment. Oh, well.

Post edited by: strider, at: 2007/08/26 16:07