High idle after stop

I have a 77 kz1000a1 stock engine with the exception of a Henry Abe bread box air filter.
the bike runs pretty good have been through the carbs until i could see them in my sleep. I have 2 issues, most likely connected. I just did the clear tube test and the levels are good, two weeks ago I just replaced all the float needles. They were completely rebuilt spring of 2012. They still leak fuel from the over flow is issue #1. issue #2 is after I ride the bike and come to a stop the idle is stuck at about 2,000. If I hold the brake and release clutch a bit and pull it back it it drops and stays at idle until i hit the gas again then it is back to 2,000-2,200 RPM. Any ideas?

Check your mechanical advance. Make sure the weights are free and the springs are not loose.

baldy110 wrote: Check your mechanical advance. Make sure the weights are free and the springs are not loose.

Yup, sounds like it might be hanging up. Give your throttle cable a looking over as well. Might be binding somewhere.

Regarding the overflow....

Fuel coming out of the overflow hose (the little hose on the bottom of the carb) is the common symptom of the 3 possible problems described below (assuming the float is not installed upside down). Remember – NO SMOKING or other activities that could ignite the fuel while working on carbs!

The brass overflow tube inside the carb bowl is damaged. When you remove the carb bowl you will see a brass tube attached inside and rising toward the top of the bowl. This is the overflow tube and it leads directly to the overflow nipple on the bottom of the carb. Normally, the fuel level within the bowl rises somewhat close to the top of this tube. If the tube becomes cracked or separates from the bottom of the carb bowl fuel will flow through it and out through the overflow hose. Checking the condition of the tube is very easy after you have removed the carb bowl from the carb. Simply hold the bowl level and fill it up near the top of the tube with water of alcohol and see if it leaks. A slight crack in the brass overflow tube can be difficult to find. You can connect a rubber tube to the overflow nipple, fill the bowl with water, put finger over the open end of the brass overflow tube and blow in the rubber end and look for bubbles. If it does the best remedy is to replace it although some folks have found creative ways to repair them.

It sounds like you have already checked the next two...

The float valve is not sealing. This may be (and probably is) just a matter of some minor dirt in the float valve and is very simple to remedy and can be done with the carbs still on the bike. Turn off fuel; drain carb by loosening big brass screw near bottom; and remove the 4 little screws on the bottom of the carb bowl. This will enable you to remove the carb bowl. You will then see the float. If you carefully remove the float you will see a stubby little needle that mates with a brass orifice; together, these two pieces are the float valve. Assuming there is no obvious damage to the needle or seat, use a Q-tip and some carb cleaner to clean the seat of the orifice and the needle. Be careful not to bend the tang that is attached to the float. This tang is the piece that the bottom of the float valve needle rests upon, and it determines the fuel level in the bowl, so bending it will change the fuel level. With the float valve cleaned it should no longer leak. To prevent a reoccurrence a quality inline fuel filter should be installed between the fuel tank and carbs. If there was damage the needle and seat should be replaced as a set; they are available.

The fuel level is set too high. This condition occurs when someone has bent the float tang as mentioned above. This condition can be checked using what is referred to as the “clear tube test.” The test involves attaching one end of a clear piece of flexible tubing to the carb drain hole and holding the other end of the tube above the bowl/carb joint. When the fuel is turned on it should rise in the tube to a level 2.5 – 4.5 mm below the bowl/carb joint. If the fuel rises higher than that level it may run into the cylinders or over the upper end of the brass overflow inside the carb bowl (mentioned above) in which case it will run out the overflow hose. This condition is corrected by removing the float and gently bending the tang to raise the float valve needle position. Doing this may take several tries before achieving the desired fuel level.

Correcting each of these three conditions involves removing the carb bowl. This task can be made easier if a short screwdriver bit is used, and depending on which carb you are fixing a mirror may help you locate the screws on the bottom of the carb bowl. Also, it is not a bad idea to have a new carb bowl gasket available in case the old gasket is damaged while removing the carb bowl. Ed

Racing idle can result from air leak through old, worn or damaged carb holder.
Or air leak due to loose carb clamp that attaches carb to carb holder.

Good Fortune!

Thanks for the feedback guys. The carb holders are brand new between engine and carb. I was thinking after reading a different thread that it might be advance related. I will do a check on everything mentioned and let you know what I find.

You do have all the vacuumn ports on the carbs plugged right ?

mtkawboy wrote: You do have all the vacuumn ports on the carbs plugged right ?

Yes absolutely, with new rubber caps even. Im leaning toward the ignition on this particular issue. The over flow issue has gone away, the idle issue only happens when the engine is good and warm. I won't get time to tear into it until Friday. at least its still ridable.

So I asked Z1 Ent. if they had replacement advancer replacement springs, they said Kawasaki does not offer them but does offer the whole advancer, for $128, ouch. Is there a third party company that made any? the poundage has to be right for them to give the correct advance so a guy really should not attempt to cut them shorter. What do you guys think?