On my 2.0 zetec silvertop I've got a set of ZX9R carbs and manifold from Bogg Bros, they were set up by Bogg's to get the car running but I am trying to get the car going as best it can for the trip down to them for the rolling road tune to make them perfect.
When I first bolted on the carbs the idle was pretty good but it's steadily got worse fairly quickly over time and my air fuel gauge I have just recently fitted is telling me they are running very lean despite my efforts with turning out the mixture screw. (currently at 3.5 turns out)

I checked my plugs yesterday and cylinders 1 and 4 looked good but 2 and 3 looked sooty. Is this likely to be purely down to the carbs needing set up properly. I don't want to run all the way to Boggs to have them tell me it's something else.

The car does not idle great and sounds pretty tappety but it revs out pretty well and the engine sounds OK when revving, possibly not as crisp and sharp as it should be but it does rev out OK and the air fuel gauge reads about right once you get it off the idle and it drives well.

Engine was fresh built with new cams and tappets.

Any advice or suggestions would be welcome.

Have the carbs been stood with fuel in them? 90% of low speed running problems, with bike carbs, is down to blocked idle circuit. A strip down and clean is the only way, ask me how I know

[Edited on 30-5-13 by 40inches]

They have sat for long periods of time yes, certainly a good few months over the winter, this winter I'm either going to start and run it every fortnight or turn off the fuel tap and run the car until the carbs are dry. Could well be this as the car did seem to idle a lot better when they first went on.

[Edited on 30/5/13 by Scuzzle]

quote:

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Originally posted by Scuzzle
They have sat for long periods of time yes, certainly a good few months over the winter, this winter I'm either going to start and run it every fortnight or turn off the fuel tap and run the car until the carbs are dry. Could well be this as the car did seem to idle a lot better when they first went on.

[Edited on 30/5/13 by Scuzzle]

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Thanks - I will have a go with the carb cleaner, so far I have been reluctant to take the carbs apart in case I mess them up but it would be good to get to know my way about them. Know my way around a set of 40/45's OK but clueless when it comes to the bike carbs.

In some cases the pilot air hole needs blanking, these are zzr1100 carbs, but the same in operation:


ZZR1100 carbs

If it's running ok, other than the idle circuit, no need for a full strip down.
Just remove the bowl, float, idle jet and idle screw and blast all the passageways with cleaner, soak the jets in cleaner while you work.
I cleaned the tip of the idle screw with a little chrome polish then cleaned with the solvent.
Do one carb at a time, and watch out for the parts on the idle screw: needle, spring, tiny washer and "O" ring. Take note of assembly, sometimes the "O" ring gets stuck in the drilling.

quote:

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Originally posted by r1_pete
In some cases the pilot air hole needs blanking, these are zzr1100 carbs, but the same in operation:


ZZR1100 carbs

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Odd things happening with pics, seems to be because there is another pic called carbs somewhere...

here's another go


zzrs

perfect

The air correction holes are blocked of to stop the carbs going week at high revs not on tick over
has boggs blocked them they did mine on the r/road day

Has the carbs been balanced on the engine ?
The air screws on my car are only 1 turn out and this is what sets the carbs at tick over speed
Are you using a bike fuel pump ?
if not you should be there the best way to go
Sorry if you know all this
Jacko

ps what model zx9r carbs do you have

[Edited on 31/5/13 by jacko]

They are C1 carbs and I am running the bike pump. went with the Yamaha pump because it had the rubber housing included which made for easy mounting to the floorpan of the car and good noise insulation. It's mounted at the tank because I know these pumps push fuel better than they pull it.

I am thinking they could be gummed up because they did idle far better when they first were fitted and they have been on the car for months at a time.
I'm going to make the journey down to Bogg Bros in a fortnights time so hopefully they will sort it all out, I'm happy enough with the way the car runs under a bit of throttle.

They have not been balanced on the engine.

[Edited on 31/5/13 by Scuzzle]

Well i must be lucky as i take my car off the road for 6 months a year and have for about 6 years and never had a problem with them gumming up
i don't know if it helps but i put redX in the fuel
Jacko

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.

quote:

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Originally posted by john_farrelly
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.

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