is the standard graph for Keihin carbs.
Should help work out which need modifiying.....
can any one give me some idears on what way to olter my carbs they tick over nice and up to 1/4 throttle just after they seam to be running out of fuel i think cos if you fether the throttle there better is this where you change the needle hight ? any help would be great
This'll be where the carbs are chnging from pilot jet onto main jet. Mine did it on my ZX9 engine. I had to get a Dynojet kit and replace the main jet with a slightly bigger size and as you said, I had to alter the needle setting.
My CVK carbs have had the air bleed hole blocked to stop that, its the one on the filter side which is in line with the needle jet.
Too start with what engine are you using? if its a pinto have a search under my name [ Jacko] there is a lot of info in the search section
Ie what size main jets how high is the needles
what model zx9 carbs are they
you may need the air hole blocked in line with the main needles
Jacko
quote:
Originally posted by jacko
Too start with what engine are you using? if its a pinto have a search under my name [ Jacko] there is a lot of info in the search section
Ie what size main jets how high is the needles
what model zx9 carbs are they
you may need the air hole blocked in line with the main needles
Jacko
is the standard graph for Keihin carbs.
Should help work out which need modifiying.....
IE put some small washers under the needles where they attach to the piston to raise them up a bit.... HAppy days 
Hi if there C model check what size jets you have mine had two different sizes
at a guess you will need about 1.6mm jets for a 1.8 l engine [ drill them by hand put the drill bit in a vice and twist the jet ]
+ you may need washers under the needle head
quote:
Originally posted by jacko
Hi if there C model check what size jets you have mine had two different sizes
at a guess you will need about 1.6mm jets for a 1.8 l engine [ drill them by hand put the drill bit in a vice and twist the jet ]
+ you may need washers under the needle head
How many washers have you at the moment ? i have two under mine. you could try more then if it runs ok remove the washers and drill the jets bigger or leave it if only two washers i dont know how many is ok to use
I need negative washers for my carbs... the needles need to go down 
Mate, Before you go any furthur seal the vacuum chambers on the top with rubber grease.. Mine was exactly the same and this will give you these
symptoms. Try that before you play with the needles etc.
If theyr zx9r c they should have 155 main jets in?? Which arnt far away from what u want.
Bogg brothers will tell you zx9r carbs will run a zetec near enough straight off the bike.
quote:by sealing the vac chamber do you mean around the top where the diaphragm sits in the top of the carb?
Originally posted by Danozeman Mate, Before you go any furthur seal the vacuum chambers on the top with rubber grease.. Mine was exactly the same and this will give you these symptoms. Try that before you play with the needles etc. If theyr zx9r c they should have 155 main jets in?? Which arnt far away from what u want. Bogg brothers will tell you zx9r carbs will run a zetec near enough straight off the bike.
Yeah take the cap off and smeer some rubber lube around the sealing surfaces of the diaprahm.. Then put the cap back on.
[Edited on 26/2/09 by Danozeman]