Danozeman
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| posted on 26/1/09 at 07:30 PM |
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Dam bike carbs and zetec again!!
Right my car 1.8 zetec zx9rB carbs and megajolt.
Its still not running right. Now i think it is way overfuelling. Its spitting fuel back out of the carbs and soaking the airfilter and using way too
much fuel.
Now the ignition map i have is a known good working one from someone else so i dont think its that. although fuel spitting may suggest this. about
3k it revs ok. below that it runs like a dog and wont pick up.
Iv changed the needles etc and made it better but its still crap. The carbs have 130 mains. n74v? needles. air corrector holes blocked off.
Iv changed the float level so less fuel is in the carbs etc. They are balanced, slides are level etc.
Also wont rev with the air filter off.
Im getting fed up with taking the carbs off etc to change things.
Any ideas?
Carbed R6 pump.
[Edited on 26/1/09 by Danozeman]
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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westf27
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| posted on 26/1/09 at 07:37 PM |
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what pump and pressure you running
555
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big_wasa
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| posted on 26/1/09 at 07:39 PM |
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What fuel pump are you running Dan ?
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Danozeman
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| posted on 26/1/09 at 07:40 PM |
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Edited post to say Carbed r6 pump.
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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myke pocock
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| posted on 26/1/09 at 07:41 PM |
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Yes, I understand that bike carbs are very sensitive to fuel pressure. I have a Facet pump and a Filter King for my bike carbs on my Estelle trials
car and have had no problems.
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Danozeman
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| posted on 26/1/09 at 07:44 PM |
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Another thing i forgot to mention. The plugs are greyish brown not black as you would expect from over fueling.
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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rusty nuts
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| posted on 26/1/09 at 08:23 PM |
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Dan , is it worth checking the valve timing and maybe putting a timing light on it and checking the ignition timing and perhaps altering the advance
curve? If it makes things worse then reload your present map. I have had one Zetec engine burn an inlet valve , it passed an emmision test but would
give a lumpy idle and poor initial throttle response. Compression test didn't really show it up but a cylinder leakage test did. Also what oil
do you have in it? the wrong oil can cause problems .
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coozer
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| posted on 26/1/09 at 08:28 PM |
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My 1.8 with ZX9R carbs + Megajolt...
I reckon yours is not over fuelling with 130 mains, they are too small IMO. Back up by the colour of the plugs.
Air screws 3 turns out, needle one groove down from the middle, main drilled out to 180.
Set up by BB and has constant CO2 and HC right across the rev range and improved from my original settings even tho they were only a little way away
from that.
Ticks over at 500rpm and revs to 6500 eagerly.
Wish I was close so I could come and sort it for ya.....
Steve
1972 V8 Jago
1980 Z750
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r1_pete
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| posted on 26/1/09 at 08:45 PM |
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Are you sure the slides are lifting, I had those exact symptoms, and it was the tops weren't sealing, thus the diaphragms weren't lifting
the slides.
To cure it I packed the recess in the carb body which the diaphragm lip fits in with red rubber lube, the carbs then worked fine, I too spent ages on
pilot settings to get somewhere near.
I understand the frustration I even bought a set of 40s, I was getting so pi$$ed off, but the CVK are working fine now.
[Edited on 26/1/09 by r1_pete]
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Danozeman
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| posted on 26/1/09 at 09:19 PM |
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quote:
I understand the frustration I even bought a set of 40s, I was getting so pi$$ed off, but the CVK are working fine now.
Thats what i did but want to use the bike carbs,
Diaphragms all nicely sealed.
I have tried so many different map settings if cant be that. Vave timing etc is spot on.
Just put my pressure gauge back on and its at about 3.5 psi. The book says they should be 1.5 to 2.5psi. Surely 1 psi cant make that much
difference.
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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r1_pete
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| posted on 26/1/09 at 10:15 PM |
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To check the fuel pressure angle, switch on and let the system pressure up, and get the car warm, then disconnect the electical feed to the pump, and
see if the running improves as the pressure drops.
Mine will run for a fair few minutes with the pump off.
[Edited on 26/1/09 by r1_pete]
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Dingz
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| posted on 27/1/09 at 12:00 AM |
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Sounds like the pressure is too high but the mains are too small, suggest starting at 1.6-1.7
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FazerBob
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| posted on 27/1/09 at 12:10 AM |
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Hi Dan. I'm running a similar set up to you. 1.8 Zetec, Megajolt, R6/Fazer 600 carbs, ZX9R pump regulated to 2.5 psi.
Mine runs a treat, main jets drilled out to 165, advance at idle 23 deg (don't know why but it works). Plugs nicely coloured, pulls well up to
about 90+ mph, then fades a little. Returns about 28-30 mpg.
Yours sounds to be in need of more fuel.
If you can get up to the Norwich area you are welcome to come and check mine out, just to make sure you haven't blocked a vent pipe, causing the
carbs to flood (like I did!!)
Bob
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mad4x4
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| posted on 27/1/09 at 07:29 AM |
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I had problems with my bike Carbs and it was due to a sticky float and crap in on carb. Small ammount of water had got into it from drip on garage
roof and was enough to foul up the float chamber.
GZXR750 Carbs - Standard needles moved up 2 Notches.
Scot's do it better in Kilts.
MK INDY's Don't Self Centre Regardless of MK Setting !
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