fuel leaking out of bottom of carb

Hi all, I have a 1980 KZ550, when i rode it back home about 40 miles, it was fine, no leaking, a little smoke.

now, when i start it up, fuel leaks out of the bottom of the two right side carbs. it stays the same even if i rev the engine, it is a constant stream, and if i tie off the end of one of the carbs it just leaks through the other lines.

any ideas? what do i need to fix to stop the running of fuel? and how do i fix it? thanks.

Its a steady stream coming out the lines on teh bottom of your carbs? If so you have float issues, most likely some gummed up or faulty float valves. I had the same problem a while back, I just went in, replaced the valve assembly, good as new.

bang on float bowls with screwdriver handle !:laugh:

haha that too

thanks. ill try it out when i get a chance,
if i were to change the valve, does anyone know how much that'll cost? or how much time itll take to take off and put back together? and if i take it apart should i disconnect the fuel line?

the float valve assemblies should be pretty cheap you can either order them thru you local bike shop aftermarket don't go to kawi. they will slaughter you on the price or you can call sudco and get orriginal mikuni assemblies for pretty cheap i just bought a full set for either my 29 smooth bores or my 33 smoothbores they take the same and with shipping into canada it was less than 75.00 and that was canadian and our dollar sucks again. also to answer your second question it should take about 2.5 hours depending on skill level to remove, clean carbs and replace float valve ass. and adjust float levels and reinstall on bike and make run again.

Z1E carries the float valve assemblies (needle and seat) other carb parts, full carb kits, etc.

Click here > Z1E needle and seat

Good Luck!

Remember, could just be some crud from the fuel tank or from the petcock lodged in the carb's needle valve. If this is not solved it will just keep plugging things up when you least expect it.

I have used these steps to avoid buying parts:

1) Replace or install a new inline fuel filter! IMHO this is not negotiable for these vintage machines.

2) Remove any rust/debris in your fuel tank or in your fuel petcock screen and or screen bowl.

3) Remove carb float bowl and clean out/blow out the float valve seat. Do not scratch valve seat or needle valve! Don't ask how I know. :blush:

4) Check that the floats have no fuel in them. Replace if they do.

5) Clean out or replace the fuel lines.

6) Check and adjust the carb float bowl fuel service level using an external clear plastic tube method (check your manual).

7) Reassemble, place bike on center stand, start her up and recheck. If it’s still leaking then replace the needle valve assembly as previously advised in this post.

If it's OK now, then the needle valves is working properly. Now, put it on the side stand and start her up again and recheck.

9) If it leaks on the side stand then it is probably the fuel service level again. Readjust.

10) If it does not leak, you should be good-to-go. Now adjust the fuel service level on the remaining carbs and retest... and have a great riding season.

Hope this helps. Best of success.

try running the carbs out of fuel..... probably wont fix problem but may help wash some of the crud out around the seal..... still would suggest at least tearing down and cleaning and see what that does......

Here's another tip for you:
If you clean the carbs, when you have the float needle out, take a Q-tip and cut it in half. Put it in a drill, soft cottony goodness NOT in the chuck! Spray some carb cleaner on the cotton and stick it in the seat. Run it around in there until the q-tip comes out clean (not orange/yellow/black). You may have to replace the Q-tip a couple of times.

If that doesn't work, before buying new needles/seats check the brass tube that is press-fit into the float bowl. i have found these to be cracked on more than one machine, which causes the bowls to leak non-stop. A little heat and some solder (did I spell that right?) and all will be fixed. Check CAREFULLY for the crack, they can be very hard to see. Sometimes twisting the tube VERY LIGHTLY with your dirty fingers will make the crack stand out, as the dirt gets stuck in the crack.

Good luck!

Jason

thanks, this is really helpful, noob question but what does IMHO mean?

In My Humble Opinion