Still carb issues

[DavidZ1R]

have you tried using a couple of the old mixture screws? there are small holes in the throat of the carb body by the butterfly valve this is the main cause of not being able to correct the mixture

Going to try and remove one screw , and then insert a pointed rubber plug, see if that changes the colour tune colour, if it does not then something else to check, have checked the float heights today, okay, if the levels are high that can show yellow all the time.

[z1bman]

there is a air jet in the back of each carb which exits out of one of the small holes by the slides as does the fuel mixture passage. if you squirt wd 40 down these passageways it should come out of these holes by the slides

[DavidZ1R]

Yes did that with carb cleaner, no obstruction, all clear

[needaz1100r]

Yes did that with carb cleaner, no obstruction, all clear

Because carb cleaner gets through only shows it's not completely blocked, it can still have old petrol varnish or crap in there, reducing the flow.

Ultrasonic cleaning should break that down, but may still need blasting and may need more than one go.

[DavidZ1R]

The saga goes on, swapped the pilot jets in 3 and 4 , took out the new Keyster ones put the old ones back in, check fuel levels I 3 and 4, okay , took out the choke plunger in 4, easy to remove withcarbs in place, cleaned that up, just a point, notice there is a rubber at the base of the plunger, could this be a problem? Anyway, started up, tick over fine, revs okay, but still shudder at low revs, checked with colour tune, both cylinders on yellow, old air screws back in, one and quater turns out, still same, up or down on the screw no change, the final option is take them off again, and power compressed air through, if that does not work, new carbs, just to ease my temper, started up the z1r and awoke my z250 from its winter sleep, at least they run okay. Frustrated from Bolton

[Zedorset]

I would still try swapping fuel pipes over, when you check fuel levels in carbs they have had time to fill up.

[PAULJAC47]

The saga goes on, swapped the pilot jets in 3 and 4 , took out the new Keyster ones put the old ones back in, check fuel levels I 3 and 4, okay , took out the choke plunger in 4, easy to remove withcarbs in place, cleaned that up, just a point, notice there is a rubber at the base of the plunger, could this be a problem? Anyway, started up, tick over fine, revs okay, but still shudder at low revs, checked with colour tune, both cylinders on yellow, old air screws back in, one and quater turns out, still same, up or down on the screw no change, the final option is take them off again, and power compressed air through, if that does not work, new carbs, just to ease my temper, started up the z1r and awoke my z250 from its winter sleep, at least they run okay. Frustrated from Bolton

Sent you a pm David re the choke plungers,that seal at the bottom goes hard with age and does not seal causing motor to run rich as choke is on partially,been there got the t shirt...Paul

[z1bman]

try putting some extra pressure on the choke plunger when the colour tune is fitted see if it makes any difference

[DavidZ1R]

Tried everything else, going to try the plungers tomorrow, hope it's that, thanks for the tips guys.

[DavidZ1R]

Gggrrrrrrr, tried the choke plunger, pressed it down, even put another very small o ring on the end, still can't get blue, even swapped the fuel lines over, no change, last resort, blast the airways and see , will put an order on for replacement set.

[z1bman]

this stuff is very good for removing gummed up air & fuel passageways just use a small syringe to drip feed it into the air screw opening & the fuel mixture opening do this 3 or four times them wash well with water


https://www.ebay.co.uk/itm/ACID-ALLOY-W ... SwofxUjfwI

[zed1015]

It would only be the choke plungers if the condition was only when it was on choke.
When off choke the plungers won't affect anything.
The flat spot when riding is a fueling issue, probably pilot or coming off pilot.