Danozeman
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| posted on 3/1/09 at 06:38 PM |
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Bike carb and Emissions troubles HELP
Evening all.
Iv just spent an hour and a half with my car and an emissions tester and cannot get my emissions anywhere near low enough.
Iv played with the screw checked all the manifolds are sealed etc it just wont come down. Im thinking i need smaller pilot and main jets.
Am i missing a trick?
I have 4 afternoons and 1 day to get it right before my test on friday and the cars in bits!!
its a 94 1.8 zetec with zx9r carbs running megajolt 2d at the min.
[Edited on 3/1/09 by Danozeman]
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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Howlor
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| posted on 3/1/09 at 06:39 PM |
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First of all what engine is it? Year? Are you running a CAT?
Steve
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coozer
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| posted on 3/1/09 at 07:22 PM |
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Right then, my zetec was set up by Bogg Brothers and the CO and HC's are spot on. However that was after SVA and mine passed the SVA emmisions
check with the standard settings as it came off the bike. Just mind, had to rev it up to 2K to get the HC down far enough.
94 1.8 zetec with ZX9R carbs same as yours.
This is how it as now:
Standard pilot jets. Mains drilled out to 1.80 but that won't affect your emissions, top end power only.
Air screws are 3 turns out and the needles in 1 groove above the middle.
Only thing that affects emissions checks are air screw position and maybe the needle position if you have to raise the revs up to 2000rpm.
Having the carbs balanced spot on is quite crucial as well.
Do the slides all lift when you rev it? If not the diaphragms need sealing properly.
What set up are you currently at?
Steve
[Edited on 3/1/09 by coozer]
1972 V8 Jago
1980 Z750
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BenB
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| posted on 3/1/09 at 07:48 PM |
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A '94 engine shouldn't struggle to get through the test, certainly bike carbs and no cat should be do-able...
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David Jenkins
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| posted on 3/1/09 at 08:04 PM |
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Dan,
I've got a carb balancing gizmo - let me know if you want me to bring it round...
David
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rusty nuts
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| posted on 3/1/09 at 08:08 PM |
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Dan, it's possible to solder up and redrill jets according to Dave Walker many years ago . If it's any help I have a couple of sets of jet
drills although I have mislaid my pin chuck..
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Danozeman
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| posted on 3/1/09 at 10:52 PM |
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David ill bear that in mind thanks may well need it.
My carbs are 155 mains and what ever the standard pilot jets are 34? i think. I cant adjust the needles as there is no grooves but could put washers
in. Ill have a bash at that next.
I sealed the diaphrams a couple of weeks ago as it struggled to rev so thats all good.
Mel, i have a set of drills and some 130 jets just in case but hopefully it wont come to that.
Il try the needles on monday.
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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coozer
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| posted on 3/1/09 at 11:02 PM |
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Dosen't matter about the how big the mains are. Its the air screw and needle position that will help... its how far the needle drops into the
air mixing tube that gives the fuelling just off the idle....
Have you blocked the air hole in line with the needle??
Wish you where close and I could help you fix it
Steve
1972 V8 Jago
1980 Z750
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rusty nuts
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| posted on 4/1/09 at 11:05 AM |
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What readings are you getting Dan? IIRC 3.5% C.O and 1200 ppm hydocarbons may be you limit?
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Danozeman
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| posted on 4/1/09 at 11:44 AM |
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quote:
Have you blocked the air hole in line with the needle??
Yep.
quote:
IIRC 3.5% C.O and 1200 ppm hydocarbons may be you limit?
co2 was about 16% cant remember the hc about 2000 i think. Well out
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 4/1/09 at 11:50 AM |
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Is the choke on? Flooding? Fuel pressure too high? Inlet restricted? Not too familiar with bike carbs these day so can't really help other than
a few suggestions. Just a thought, you have got the fuel supply plumbed in correctly and not to a breather?
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MikeRJ
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| posted on 4/1/09 at 01:06 PM |
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Is the ignition timing set to a sensible value?
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