Hi
A while ago I bought 2 sets of zx6r carbs , one on a pinto manifold (off Ebay) to replace a worn 38DGAS .
I fitted these a few weeks back but had problems with over fueling / fuel leaks ,this was due to a faulty regulator and a facet fuel pump that constantly pumped fuel.
Since then i've replaced these with a zx6r fuel pump and the leaks have stopped.
Problem I have now is the engine will idle but put any revs on it bogs down. The guy I bought them off assured me they ran fine and came straight off a running engine.
Right I believe (not 100% sure) from scratch you have to drill a jet out to 1.6mm as a starting point, and block off another jet on the carbs.
I've taken some pics of that other set I have , can you point me in the right direction as to what is the jet to be drilled and the one that wants blocking off if this is correct as I presumed Cheers

[IMG]http://i215.photobucket.com/albums/cc140/daveat40/120_zps4jttxyod.j pg[/IMG]

[IMG]http://i215.photobucket.com/albums/cc140/daveat40/117_zpsn6iiiyca.j pg[/IMG]

Spent loads of time on these carbs. They will run an engine as standard fine generally upto about 50% full load throttle. If the engine is bogging down I would put money on the pilots being blocked - take them out, spray some carb cleaner into a glass then leave them to soak for 24 hours. A few other things to check -
Have the carbs been balanced?
Do the diaphragms lift when revved?
What are the idle screws set to, generally all the way in then 2.5-3 turns back out.

Hi davidimurray The carbs are just as I got them and I haven't altered anything..I don't know anything about these carbs
I bought them as running so I could bolt them on and take it to a rolling road and have them sorted..
what are/is the pilot jet? and what is the idle screws? I just wanted to check to see if they had been drilled to 1.6mm.
Ill check the other pilot-idle if I know whats what..Cheers..Dave

i've just googled them and got a pic ....ill check there clean and set the idle and report back..cheers

Nothing needs blocking off on ZX6 carbs. It is ZX9 that need an air hole closing up. The main jet is the one that may need to be made bigger. This is easy to identify as it is the jet that the needle goes through.

Stu

Make sure you clean the jets in carb cleaner - I tried blowing them through for about a month and it was only when I soaked them that it solved all my problems. Balancing is important for smooth running, without it the engine will run but most likely lumpy and possibly with the occasional misfire, you will probably also get spitting back out of the carbs.

first of all i would recommend to clean carbs, in photo i saw some dirt.

There my spare set Pablo Escobar and yes they have seen better days.
Right to day I fired it up and revved it from the carb.previously I've been useing the throttle pedal.
The carbs idle ok,so I left them for a while to warm the engine up on idle.
Went to put some revs on after the engine was warm and it started to pop and spit out of the third carb going to No3 cylinder.
Then it bogged down again and wouldn't start,so I removed the carbs and emptied the fuel out of them.
Doing this I noticed that when I push the needle up on 1-2-3 carb it makes a sucking noise but on 4 it didn't .
So I removed the black plastic cover and found that the diaphragm on that carb had been trapped

Also the choke bar was sticking and wasn't always going back.Ive sorted the diaphragm out and all the carbs sound the same now and replaced the choke arm with the one off the spare carbs and all seams ok.Going to clean the pilot jets and try them tomorrow...

Am I right in thinking the main jet doesn't adjust and I can unscrew this,

Clean it and put it back without disturbing anything..?
What size should it be drilled ? (Standard 2.0l pinto) Thanks..Dave

what size are your carb chokes?
i have flow jets drilled to 1.7mm

quote:

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Am I right in thinking the main jet doesn't adjust and I can unscrew this,

Clean it and put it back without disturbing anything..?
What size should it be drilled ? (Standard 2.0l pinto) Thanks..Dave

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Cheers SJ that's good to know,I had already ordered a 1.6mm drill (pack of 10)to check them just in case.

I've just quickly removed one to check and it doesn't look like it's been drilled any bigger at all.
I realy have my doubts these came of a running car...
37 chokes I believe Pablo that's of the net..thanks Dave

My post should read 2.0 zetec, not 2.8, though it is a nice thought!

Hi I've soaked the idle jets and sprayed carb cleaner through them.
I checked that all the holes had a good spray coming out of them.
Removed the main jets sprayed these(think there standard sized)
Sprayed carb cleaner through the jet under the trumpets.these where clear and spraying into the throat of the carb.
So l fixed them back on the engine,now it won't start.
Turning the engine it's trying without any throttle and every now and then it fires and runs on when the ignition key is turned off.
If I put any kind of throttle on while cranking it bogs down and struggles to turn
Any ideas???...I haven't altered the mixture screws.Should I screw them all in and back off 2.5-3 turns,what do you think.Thanks.Dave

Main jet controls the top 1/4 to WOT so nothing to do with idle.

Air jet controls idle. Screw them all in and out about 2.5 turns.

When you whack the throttle engine map lifts the diaphragms and opens the pilot jet. Important thing here is that they are balanced correctly. Standard pilot jet will be fine as is.

Check the float heights, fuel level is important in the float bowls.

After that its needle position and on to main jet size.

Air jet = first 1/4
Pilot jet = second 14
Needle position = third 14
Main jet =fourth 14

Well would you believe it..checked the plugs and they where black and wet.
Bought some new plugs,but of choke and the bugger fired up .
Got it warm,adjusted tickover and it revs sweet as...ill take it to a rolling road once I've sorted a few
Suspension/body work out..well pleased thanks for your input..Dave

I've finally got the car so I can drive it on the road,taken it for a quick run today and I'm very disappointed with the power these achieve.
Before in the 38dgas it would fly in every gear kicked out 105 bhp.
It's like driving a car with a blowing exhaust manifold...engine idles ok pops a bit through carbs until it gets warm then revs ok,just doesn't seam to have half the guts the dgas had.Any ideas? There's no advance take off could this be the problem ....? Thanks Dave

The problem will still most likely be incorrect fueling - correct me if I am wrong but having skimmed through the post the fueling has not been checked with any wide band afr equipment? In which case jetting is being guessed (and this does not work).

Get it tuned with the right equipment and I guarantee you will not be disappointed.

^^^ what dan says

But once you've got the carbs sorted it sounds like you'll want to sort the ignition properly too
(I take it that your running a bog std dizzy with the vac advance just disconnected?)

I checked the jets when I got the 1.6mm drill and they where already drilled to this size.
I was advised to drill them to 1.6 as a starting point ,as they would only need drilling larger not smaller and 1.6 was a starting point..
I've also advanced the timing,this did make it feel better but also made it pop from the exhaust like a misfire at idle.ill get it on the rollers and set up properly,just thought I'd feel a big difference.ive removed the exhaust manifold at the moment to sort out some clearance issues,it was close to the steering column..once it's sorted I'll book it in for a session and see what they can do.
It is running the standard vac dizzy and yes I've just disconnected the vac pipe..

The vacuum advance being disconnected will not affect performance (only fuel economy and light throttle response at light cruise). 1.6 is a sensible starting point but correct jetting can vary depending on so many factors, so chances are it will still be out by enough to hamper performance noticeably.

Hope so ,and I'm sure your right Dan.Be interesting to compare the print outs when they have done..