First start post rebuild Z650 - disaster!

[Oggers]

Well - I bought a suitable o ring for the petcock, connected the battery, tap to prime to fill, and it started. Trouble was it absolutely drizzled petrol all over the engine/gearbox under the carbs. A severe fuel leak coming from the area shown by the white arrows in the attached photo...

I did not do anything to the carbs except clean them up. It is true they were on their side and quite possible upside down, but I did not take anything apart. I am thinking stuck float(s) or dislodged needle valve or something? However, they did not overflow from the small overflow pipes on the carbs - near the drain screws - which I think is a little odd, just at the location of the white arrows. The bike was on centre stand and the carbs are canted forward a little, but even so.....

Is it possible to remove the float bowls in situ? Don't fancy taking the carbs out - a real pig with all the air intakes.

Gave the carbs a bit of bash with a soft mallet to see if it freed anything off - no joy.

Could it be something else?

All thoughts very welcome...

[warren3200gt]

You can do Oggers they will come off ok but they are a bastard to get the bowl screws all back in and tight.
On the basis of do it once do it right I would take the carbs off and do a full strip clean and set up off the bike.
It may well be the fuel T and connector O rings are dried up and leaking which means they will have to come off anyway to replace them. Also if the bowl gaskets are the paper oem type they dry up and leak until they swell up again and seal however if thats the case your bowl fuel height is too high.

[DavidZ1R]

Agree with Warren, you can take the bowls off in situ, 2 outside ones not too bad, inner 2 can be a bugger to get screws in .

[Oggers]

Warren

Yes - thinking to take them off to do it right - arrrrgh! Very frustrating after all the work!

Agreed about Tee and O rings - they could well be gone. The tee does rotatate in a looser fashion than I would perhaps wish - but that said, I cannot see any leaks from there

Do you agree that the likely cause is a stuck float, needle valve not seating right - or maybe crud in the seat?

What else could it be?

Many thanks for all you help and advice by the way, Very much appreciated

[warren3200gt]

If its not leaking from the connectors/T and is indeed leaking from the bowls the only things it can be is the the bowls are filling to much. Possible causes, float height set wrong, valve / seat not sealing for whatever reason, crud, worn needle seat, floats catching bowl sides and sticking.
Leaking from the overflow will normally be needles not shutting flow off. Leaking from the bowl gasket is normaly float heights wrong. Leaking from both your in the shit and need a beer.

[Oggers]

Aye..right enough! ....and I'll check it all out first with another fuel hose from the tank BEFORE I put them back!

[Kev1R]

I had a leaky carb bowl on the Z1R yesterday. Symptom was one of the 4 overflow pipes was constantly taking a leak. I self diagnosed a stuck needle valve = Probably due to lack of use this year. Why is it always one of the inner ones?
I removed the bowl and float (& the needle simply dropped out) & cleaned everything up.
If you do this in situ just remember you only need a strong turning force on the bowl screws when initially loosening or tightening up - so maybe only half a turn or so. For the majority of the turning motion you can use small screwdrivers with plastic handles you can cut them to the desired length to get in the space available and you can get a 'normal' screwdriver in (or a pozidrive end on a small shaft) to do the final tighten up that way.
Getting the needle to stay in while you replace the floats is the tricky bit!
I put the needle in place with a turn of dental floss and then replaced the floats and pulled the floss clear so the needle dropped onto the float tang.
Then replaced the bowl. Took about and hour and then went on a run into Derbyshire - so far all good - no more leaks.
Cheers Kev

[Oggers]

Chaps

Many thanks for all the useful replies. These forums are exactly why the internet was created and given to us all for free. A magnificently altruistic concept. Sharing of information by all for all, not for ogling naked ladies ---ahem.. ..

Anyways, after a couple of hours fiddling about, herewith the results from the Scottish jury

Carbs off the bike, nearside float bowl removed to see if anything obvious lurked within. Nothing found. Float(s) given a modest waggle, bowl replaced. Then decided to see exactly where it leaked before moving on as I loathe taking carbs apart for no good reason. Tank off, put on bench, connected to carbs from the fuel tap to the fuel hose fitting - the one with the groove - with a length of hose. Tap turned to prime, petrol seen flowing through the in line filter. Waited in anticipation for leaks.....nothing...Waggled carbs, still no leaks. Very very odd. I refuse to believe it was simply the nearside carb floats sticking or something. However, bouyed by this, carbs and tank replaced, connected up, started first kick. Tap turned to reserve - not much petrol in tank - still no leaks. Hurrah! So far all still good, but no firm idea why!

A few minor things noted when the bike was running and on the main stand

All indicators flash when switch energized. Experience suggests this is a bad earth somewhere. Hopefully an easy fix.

Rear wheel spins rapidly in neutral - even when clutch lever is pulled in. I assume the thicker new oil - 20/50 has an effect on the plates here.

Sounded like a bag of bolts when first started. Oil and filter were changed, engine totally drained. Quieter after around 3 minutes or so when oil circulated. Topped it up by the sight glass. Started again, still slightly rough, but then I have not given the oil much of a chance to fully coat things, and the carbs may need tweaking a bit. Still also have to replace the air intake rubbers from the airbox. I'll also check static timing.

Front brake light stop switch is u/s - for the moment. Again, experience suggests these switches take a while to firm up and provide the connection required after a change of brake fluid. It was however well bled, and the lever is firm. To eliminate any wiring issues, I assume if the two connections at the switch are bridged, the stop lamp should illuminate?

A note on the fuel connection to the petcock - I didn't fit a suitable o-ring despite buying 10 or so which looked right from the garage, but did not fit. It must be highly specific if there is one. I didn't use PTFE tape either. It seems a very tight fit, interference perhaps? and I cannot see any leaks from the connection. I wonder if it really does need an o-ring despite the groove? As aforesaid, it didn't have one when I first pulled it.

Starter does not engage if clutch is not pulled in - inhibitor switch works! One to Warren....

[warren3200gt]

Gratifying when they actually do what they are supposed too.
Front brake switch, bridged should illuminate brake light and idiot light.
Rear wheel does spin when on stand in neutral. Should be able to easily stop it if you put your foot against the tire.
Presumably you bench sync'd the carbs? Now its running you need to live sync them. Evens and smooths things out hugely.
Have you wet tested the float fuel levels with the clear tube method
Getting the carbs set correctly on these bikes is critical to good and smooth performance.

But the first and biggest hurdle is accomplished.
Congrats

[Pigford]

Many thanks for all the useful replies. These forums are exactly why the internet was created and given to us all for free. A magnificently altruistic concept. Sharing of information by all for all, not for ogling naked ladies ---ahem.

Why not do both

[Oggers]

Warren

Thanks for that.

Rear wheel spin - yes they all invariably do it, and easily stopped by foot or brake, but this seems to spin rather faster!

Carbs - One reason why I did not want to fiddle with them too much or take them apart is that I was assured by the PO that they were spot on and balanced correctly. Riding the bike beforehand I had no reason to doubt that. I'll blow some carb cleaner through and may tweak the idle air mix screws slightly, but I am loathe to fiddle any more at present. I have a simple 4 cylinder manometer used on the 400/4 which I can use to connect to the inlet manifold nipple of each carb to balance when running - and yes they are all capped off at the moment.

[warren3200gt]

What was the plug colour like before?
Float fuel level makes a big difference aswell. Easy to check, not so easy to adjust but well worth at least checking or doing whilst they are off the bike.

[kev edwards]

Nice to see a happy ending, i see you have the pumpers with the two diaphragms, they can be a problem unlike the single type, i have the same carbs but have removed the lower diaphragm and slightly modified that area so they work like the 28s, one less thing to worry about now.

[Oggers]

Warren

Old plugs looked OK. Replaced with new. I'd like to give the bike a run or two before I contemplate fiddling with carbs. Float height - manual refers to a "special tool" which of course I don't have. Usual thing is to check height against the side of the float bowl and bend the tab accordingly- what happens with the Z?

[DavidZ1R]

Home made jig, works great, special tool available from z power, only cheap.