Not running well

Alright everyone, working on recomissioning an 81 KZ440A2 LTD, about 13k on the clock.

I get quite a dripping of fuel leaking from the bottom of cylinder 1 carb bowl - I have set the float levels so this is odd.

The engine will idle ok around 1000-1200 RPM. If the throttle is slowly rolled, and then released it will hang 3-4k for a little bit. If rolled on somwehat quick, the engine stops.

I've done quite a bit to it recently:
Valves back in spec
New plugs
Oil & filter change
New slide diaphragms
Really thorough internal carb cleaning
Bench sync of carbs
Idle mixture screws 2.25 turns out
Fuel levels set with clear tube 2mm below top of float bowl
New fuel hoses w/in-line filter
I have not replaced the rubber tipped float valves, but they look quite good at the tip.

Pulled the plugs and cyl 1 looked spot on, cyl 2 was perhaps a bit lean.
Has stock exhaust and airbox.
Made sure the throttle cable was not hanging.

Where do I go next?

splazoid wrote: Alright everyone, working on recomissioning an 81 KZ440A2 LTD, about 13k on the clock.

I get quite a dripping of fuel leaking from the bottom of cylinder 1 carb bowl - I have set the float levels so this is odd.

The engine will idle ok around 1000-1200 RPM. If the throttle is slowly rolled, and then released it will hang 3-4k for a little bit. If rolled on somwehat quick, the engine stops.

I've done quite a bit to it recently:
Valves back in spec
New plugs
Oil & filter change
New slide diaphragms
Really thorough internal carb cleaning
Bench sync of carbs
Idle mixture screws 2.25 turns out
Fuel levels set with clear tube 2mm below top of float bowl
New fuel hoses w/in-line filter
I have not replaced the rubber tipped float valves, but they look quite good at the tip.

Pulled the plugs and cyl 1 looked spot on, cyl 2 was perhaps a bit lean.
Has stock exhaust and airbox.
Made sure the throttle cable was not hanging.

Where do I go next?

Since you're sure the fuel levels are good based on the clear tube test the leaking carb would be either a sticking float valve or a cracked overflow tube (if your carbs have them). Regarding the throttle roll-on issue, have you cleaned and lubed you timing advancer? Ed

This bike does have overflow tubes. I checked to make sure they hold water up to the top of the bowl, which they do, so I'm thinking they are not cracked. They could be though - whats the procedure for fixing them if they are?
May as well buy some float valves from Z1E to be on the safe side.

How do I go about checking the timing advancer?
I know this bike does not have timing points, but instead has a pickup coil type thing.

I've got the manual, so I guess I can look there as well.

Sounds like a leaking float valve.

The leak must have developed after successful completion of the clear tube test.

Wondering if any gasoline at all was allowed to enter the carbs before installing the New fuel hoses w/in-line filter ?

Good Fortune!

There would have been a bit of gas that was not sent through the inline filter - I did my clear tube test on the bench from an unfiltered auxiliary tank.

Im going to stop being cheap - I've ordered rebuild kits and going to see if that will resolve the issue.

And going to use the inline when i double check the fuel levels with new valves.

Thanks for the input guys!

splazoid wrote: There would have been a bit of gas that was not sent through the inline filter - I did my clear tube test on the bench from an unfiltered auxiliary tank.

Im going to stop being cheap - I've ordered rebuild kits and going to see if that will resolve the issue.

And going to use the inline when i double check the fuel levels with new valves.

Thanks for the input guys!

Might not need re-build kits.

The float valve and float function must have been okay when the clear tube test was successfully performed. Otherwise, the fuel level would not have stabilized during the test and would have kept rising in the clear tube. There would have been no dripping of fuel at this point in time, and no leaking float valve.

But now there is dripping of fuel, so "what changed after the clear tube test?"

Given that introduction of gasoline into the carb was the only change between leaking and not leaking, the gasoline is the likely culprit and probably resulted in the now leaking float valve.

As known, entering gasoline passes through the float valve, where only the slightest bit of crud or grit may prevent the necessary perfect interface between the float needle tip and the orifice in the float seat.

Many perfect carbs have needed re-cleaning (particularly re-cleaning of the float valves) after unfiltered gasoline was allowed to enter.

Good Fortune!