Z900A4 float levels

[Al]

Well done.
How did it ride and run? Coughing, spluttering, holding back, missfiring etc?? Pulls like a train?

Plugs are No 1 to right to No 4 on left.

I am going to hope you mean the other way round!
Looks like the 'air filter out' did not make a significant difference so you could say; it, and the gauze mesh, snorkel etc are not overly restrictive. No waterproof trousers in there then
Number three seems to have 'cleaned up' a bit and now looks not unlike the others. I guess the (#3 ) needle jet, jet needle, extension and or the main jet there is oversized / worn / damaged / drilled out / split or some such.

If you left it to me i would have you run it down weaker 'till the exhaust crackles and it nearly explodes but i'm trying to moderate my ambition and keep some perspective. It looks to be on the safe side of 'correct'. You will get more torque running it richer which is what you say you need for pottering and its only at the expense of a small proportion of the available 'peak power' which seems not to be youre preferred option. If you run it down weaker the throttle becomes like and on / off switch so i guess all being well you have arrived!

I would keep a periodic view on the float levels, engine temperature and also on the development or absence of 'colour' on the plugs.

AL

[sprint]

Yes you are absolutely right, should be No 1 on left and No 4 on right.

Very much my own opinion that the air filter in or out does not seem to make much difference.

As I indicated I have previously swapped all jets, main, pilot and emulsion tubes between No 3 & 4 and it has made no difference, so that really eliminates them and only leaves the needle and needle jet. The needle looked fine when I dropped it by one groove and can't see why No 3 needle jet should be different to all the rest, though clearly it could be the culprit? Not sure if/where you can get good quality needle jets as that could be changed without having to remove the carbs again.

I need to check/adj the vacuum balance again, do another colourtune and as you suggest run it for a while and see how it goes and if No 3 fails again?

With regards to colourtune setting, do you adjust till the yellow flame just turns blue and then leave it there or go a bit further into the blue?

With regards to No 3 the colourtune setting was around 1 1/4 to 1 1/2 turns out but is currently at 2 turns deliberately to weaken the mixture. Should I just leave it at whatever the colourtune setting comes out at?

[warren3200gt]

Colour tune a about 1500-1800 rpm. Adjust until full ble then screw back in until the VERY MEREST TINCY WINCY bit of orange can be seen.

[Bert]

I've been reading this thread with interest as I am also experiencing similar running issues. The thing that is the most frustrating and from the comments in this thread many others will agree is the inconsistent measuring of float height from a static to a wet height. I purchased a "tool" for wet measuring and it is now in the bin as it's impossible to get a steady reading... In my moment of frustration I came up with a way to see and read a float height measurement in real time so to speak.

I mounted the bank of carbs on a wooden batten fixed in a vice so the bodies are in a near horizontal plain.
Cut some small squares of card to use as shims on three of the floats to effectively close them.
Orientate the carbs the correct way up.
Connect a fuel supply and hang up higher than the carbs.
Hold a clear plastic food container of a similar size to the carb body and turn on the fuel.
Watch the bowl fill up and close off showing precisely the distance below the edge of the body.
As the card is holding the other float valves closed you can easily measure all four carbs without having to mess about as all you have to do is pull the card shim from the carb you want to test leaving the others closed.
I marked a line at +3mm down from the rim of the plastic container as a guide.
You can see exactly what's going on and where the cut off height of the fuel is.
For my carbs with new Keyster valves and seats the static height is at 27.5mm to gain a correct wet height.
Hope this is of use and apologies if it's been suggested before.
Cheers, Rob/Bert