My kz650 carb issues please help

Hey guys,
New to the forum. I’ve searched a bunch and haven’t seen anything that fits my search quite right. I have a 1980 kz650 with pod filters and stock exhaust. I have completely cleaned the carbs multiple times and installed the dynojet kit. Right now I have the bigger jets in that came with the kit (122 I believe?). The bike was running with solid idle but had no power and would backfire one good time after throttle. The timing has been done. The plugs looked a little black so an article said raise the needles. I raised them a slot up (2nd slot) and now the bike runs worse. As soon as I put it in gear it will die, and gas is leaking out of every carb overflow at different times. I have installed a manual petcock so maybe it’s getting too much gas? I set the float levels the last time I cleaned out the carbs. The air screws are at 1 1/2 turns out. Syncing the carbs is the only thing I haven’t done because of cost. Please let me know if there’s anything else I can try....
Thanks in advance
Kris

Dropping the needle leans the mixture, not raising it. I doubt needle changes alone will help the situation as described though.

Fuel leaking suggests a float needle blockage problem. Did you remove the float needle seat and make sure those parts are in good shape? You might want to perform the "clear tube" test as described in the factory service manual to check fuel level in the bowls since that seems like an obvious issue with your bike. Once you get the fuel level/leakage problem sorted then move on to the rich condition, if it still exists.

The instructions I have say position one is the leanest and 5 is the richest. Yes I cleaned all the float valves and seats

No 1 is the leanest no 5 is the richest counting from the top down. Overflowing carbs mean that either the float valve is not sealing, the float height is incorrect or the floats have been put back in upside down.

How did you adjust the floats? With the issues you are having, you need to take the carburetors off the bike. Remove the bowls. Remove the bowl gaskets. Use a carburetor float height measurement tool of a small millimeter ruler and set each float to 25mm from gasket mating surface to top of the float. Now do a wet set on the floats using the clear tube method. This has probably already been explained but the 25mm setting will get you close. Whatever you did to adjust the floats obviously isn't work and may not have been done correctly. Good luck! Stop screwing around with the jet needles and jets till you get the float height correct. The wrong float height will not only cause leaks but will also richen the mixture to the point where you will be misled. For you application, the Dynajet kit is really not a good idea. I doubt they did a lot of extensive testing for your particular bike and the same too-skinny jet needles are used in every kit they sell for vintage VM equipped bikes. They also didn't provide a pilot jet or needle jet.

Put the stock jet needles back in; reclip to 4th slot counting top to bottom. Then buy some Mikuni #110 main jets and #17.5 pilot jets and you are done with jetting for the pods. I think you have a pilot mixture screw? This should be about 1 3/4 turns out from VERY lightly seated. Don't tighten the mixture screw too tight as it WILL break the tip off in the little hole it seats in.

Hey guys, thanks for the advice so far. Cleaned out the carbs again and set the float heights. Stopped my leaking issue. I put in the original main jets and tried to get the bike going. It started right up but would bog down under any throttle. So I ur in the dynojet 118 jets and it got a little better. It’s rideable but backfiring and no power. Still wants to die with heavy throttle. I have heard of people getting rid of the accelerator pump. Would this alleviate any of my problems? Also would the needle position have anything to do with what I am describing?

Have you done a valve adjustment?
Steve

No I’m not farmilar with the process. Is there a how to on here?

Not a how to but a service manual you can read before you do stupid and expensive things on your bike.


kzrider.com/modules/ServiceManuals/Kawas...Service%20Manual.pdf

Michael