Zx9r carbs 1.8 blacktop fuelling problem

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john_farrelly

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posted on 3/11/13 at 04:46 PM

Zx9r carbs 1.8 blacktop fuelling problem

Zx9r carbs on 1.8 blacktop

Help needed zx9r bike carbs on new 1.8 blacktop engine. Running edis and a mega jolt. Bogg bros cleaned and fitted carbs
To manifold. Car idles fine soon as you rev it just cuts out. This is with me just running it on edis. Fitted new spark plugs as they were
Black which confirms over fuelling. Bogg brother drilled jets out to suit engine. But the car is throwing loads of unburnt fuel down the exhaust. Fuel mixture screws were
Out 3 turns changed this to one turn but made no difference. Starting to do my head in now so help would be much appreciated. Also
Bogg Bros provided me fuel pump to suit carbs so no need for fuel regulator.

macc man

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posted on 3/11/13 at 05:00 PM

I have a similar set up on a 2.0 silvertop engine. First i would take off the megajolt and run it in limp home mode and see if it is any better. Then I would check the fuel pressure. as they need very little pressure. A bike pump is the best to use. Check the floats in the carb for sticking & make sure the diaphragms in the carbs are not damaged. It could be just an overhaul is needed.
I am sure if you rang Bogg Bros they would be able to give more advice.

jacko

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posted on 3/11/13 at 06:30 PM

Easy answer Ring Dave Bogg they are great people to talk to and will tell you what to do
Have you had it on Boggs rolling road ? they told me mine had to be to set it up properly

john_farrelly

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posted on 3/11/13 at 07:32 PM

Not had it on there rolling road but will. Still working on it. And it is running in limp home mode have disconnected the mega jolt. Also the pump is a bike fuel pump supplied by Bogg bros. Someone has told me might be pilot jets in carbs blocked up with old greasy fuel.as it idles fine but as soon as I touch throttle just dies.

puma931

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posted on 3/11/13 at 08:17 PM

Get it set up on a rolling road, best money I spent on mine was with torque tune who setup my timing and carbs.

john_farrelly

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posted on 28/11/13 at 06:20 PM

Still need help with this. Spike to Bogg bros there not sure what problem is. Could it be wiring
But I would of thought it wouldn't idle if I had some wiring wrong. Like I said I have check the carbs all look fine.
But still dies as soon as I give it the smallest amount of throttle. PLEASE HELP ME ITS DOING MY HEAD IN NOW.

jacko

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posted on 28/11/13 at 07:11 PM

I am sure Boggs will have got the carbs right but if you give us some more info we may see something that may help you

What size main jets have you for a 1.8l i would think you would want 1.6mm jets
is it washers or clips that lift the needles [ what model zx9r carbs are you using ? ]

Sorry i dont know anything about megajolt to help you

r1_pete

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posted on 28/11/13 at 08:45 PM

Pretty sure your problem lies in the seal between the carbs, diaphragms and tops, any air leaks and the slides won't lift and give the symptoms you are seeing.

I've cured several sets by taking the tops off, and re assembling with a smear of rubber lube on each side of the diaphragm where it seals between the carb and top.

Also make sure the locating peg in the rubber is seated properly.

davidimurray

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posted on 28/11/13 at 09:44 PM

If you put your foot down will it rev up?

I had a problem where mine would idle, but would cough and spit if you slowly accelerated but ran better if you popped your foot down and revved it up quickly.

Turned out to be the pilot jets in the carbs. Blew them through and worked OK for a while but would then do the same thing again a few weeks later. Took all the jets out and they looked clean, soaked them in carb cleaner for 24hrs and was amazed at the crap in the jar. Since then has run beautifully

john_farrelly

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posted on 28/11/13 at 10:34 PM

As soon as I touch the throttle it dies. Doesn't matter how hard or slow I throttle it. I took pilot jets out and were clear.
As for what size jets are don't know told Bogg bros what engine they were going in and they sorted the rest.

davidimurray

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posted on 29/11/13 at 05:46 PM

When you say the pilots are clear have you just looked through them? I blew mine through and they looked clean, even putting thin stranded wire through them. There was still a lot of crap that came out of them when soaked in carb cleaner. It would seem that the ethanol from modern fuel can go sticky and line inside of the nozzles.

Do your carb diaphragms try and lift when you open the throttle?

With the ignition on, but engine off does the fuel pump stop ticking? Try lifting each carb diaphragm and look down the carb with ignition on but engine stopped. Is there any fuel coming out of any of the nozzles/jets? If there is you could have passing float valves or incorrectly set float heights

john_farrelly

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posted on 29/11/13 at 10:20 PM

Yeah I just looked through them and they look clear. Also the fuel pump
Does stop ticking.

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