yeah that does sound a bit crazy. 130 mains would be passable on late emssion style tubes on dellortos, but not on normal emulsions.

the idle jet size is fine, but i think you might want an F9 holder (do not quote me on that!!) that tends to be a popular combination

emulsion tube wise you want an "early" starting tube that holds a steady mix but leans off slightly at the top end. the equivalent of a .7 tube in dellortos.

Early starting tubes will make the mains come on sooner with the 28mm chokes and give the car more torque so to speak

mains go down to about 115

airs you could probably stick with

HI. thanks for advice much appreciated took top off one carb on sunday it was the one that gave me my back firing trouble and was a pig...all jets were clean and only a little bit of dirt in botom of float chamber so why the back firing which last week blew away my manifold to carb gasket well the float was not set at all....measured how and when it would be working to realise there was hardly any petrol in chamber so re set to ruff setting 7.5mm closed and 15mm open. Fuxxxg hell what a difference no stuter or the big hole at 30000 rpm just smooth rpm. Now just to get it right (sorry it is so long )

So all who read this don t forget float settings.....

I need some advice from people in the DMTL-know. I'm a twin dellorto guy, so the jetting i know is irrelevant.

I've bought a dmtl ebay, either from a 1600/1800 golf. It's a 32-34.

After whipping out the jets i can see, i have...

Unknown airs (can't see the markings)

f22 emulsions

117 mains

55 idles (i assume the higher seated jet stack are these)

Unknown airs again

f25 emulsions

125 mains

60 idles

Any thoughts on whether these will be suitable for a 1400 with 4 branch.

Also, is there a knack to taking the jets out.. they are quite low into the body with no room around them- i flipped the carb as it was off car - but what about on car?

Cheers

Edited 13 March, 200917 yr by twin40racer

[After whipping out the jets i can see, i have...

Unknown airs (can't see the markings)

f22 emulsions

117 mains

55 idles (i assume the higher seated jet stack are these)

Unknown airs again

f25 emulsions

125 mains

60 idles

Any thoughts on whether these will be suitable for a 1400 with 4 branch.

Also, is there a knack to taking the jets out.. they are quite low into the body with no room around them- i flipped the carb as it was off car - but what about on car?

Cheers

If it helps, I'm running the following jets on a 1300, GK inlet, twin downpipe, standard cam, and they work fine, gettin revved fairly hard.

Primary: Main 100, air 155, idle 45, F22 emulsion

Secondary: Main 120, air 185, idle 70, F25 emulsion

We've run this on an air/fuel meter on the road, works fine. I know sec idle seems high, but power smooth through the range because of it. if I look around, I might find the jets I used on a 1400 nova SR, if you want. I pick them out with a pair of long-nosed pliers on the car.

Cheers!

Cool, thanks for the reply. Doesn't soind like i'm too far off anyway.

It would be awesome if you could find those jets. I'm running a 4 branch, ABD and standard cam for now, but maybe get a GT cam and GK mani and complementaries.

this is my jet setup, for a tuned ABD, save your pennies on the GK manifold, the 2G one is better, look at the power/torque curves from the second set of rolling road data in my member gallery. GK manifold makes more power above 5.5k thats it, and wayyy less torque below. as for getting the jets out, unscrew them and then poke a thin bit of rod down the middle, angle it to one side and pull em out, works a treat.

Primary

idle: 45

Main: 115

emulsion: F22

Air: 185

Secondary

Idle: 70

main 115

emulsion: F30

Air 170

thank you Pete

Sounds good again. Looks like it'll be a bolt on and see what happens affair. A 2G manifold is on its way, good to hear you think its useful for torque lower down... especially in a heaver golf. the g60 will be for foot-down action now, so the low down should be useful in teh more economical golf. Thank you

/drink

Busy weekend, sorry! Jets we used in 1400 SR nova were :

Primary : Idle 50, main 117, air 185, tube F22.

Secondary : Idle 60, main 125, air 200, tube F25

Hope these are of some help.

Cheers

yep, brilliant help. Sounds as though my jets may be near enough! I'll update when i know.

Can anyone tell me where people hook up the vacuum advance for the dizzy with the weber, is it off the vacuum line on the back?

if you've got it off the car there should be a brass connection near the base, the port should be right next to the butterfly. you should be able to use the one highlighted in yellow on the carb photo on the first page of this thread

Thanks Chris, i thought that was probably the one to use but thought i'd check before i ruin another dizzy.

i found out the other day my parade has a weber carb, i can't seem to find anything out about it

can anyone help??

Take the air box, or air filter off and get a number. Someone might now something about it on here

My car is now fitted with a DMTL, but i've had some problems...

The car won't idle and only runs if you keep it above 2000rpm when cold, and when warm you can kind of get it to idle at about 2000rpm +. I've checked all the jets i can see (top 4 stacks) and they are clear. When you drive it there isn't any power on the first stage and there seems to be a better pull with no throttle than part. The second stage seems to work better, possibly as it should. Using the brakes makes the engine die, and it seems the servo is getting no assist (was a fun 25 mile drive home!).

With this in mind i thought that maybe there is air leaks, so opening the throttle weakens the mixture more, due to it already getting air. And the lack of vacuum is why the brakes have no assist.

I'll check for air leaks later,

Any other ideas?

Cheers

Check for air leaks definitely. you could be right in thinking that its far too lean with extra air entering from somewhere

Also make sure the little one way valve between the manifold and the servo is the right way round!

check your idle jets are seated properly

Fuel pressure and supply correct? i would have thought that the single carbs like that wouldn't require as much fuel as say twin dellortos and benefit from a send and return with swirl pot. if you've kept the high flow pump then you could be inundating the needle valve seat and then flooding the carburetor. this may be the cause of improvement when you get it to 2000 rpm.

Thanks,

I'll get a swirl pot i think, just to be safe. At the moment its just the pump, through a regulator and to the carb.

I'll check that valve, though it seems strange that it would be wrong... Unless mk2 polo coupe s's had no servo assist?

The jets all seem to be located right, idles sat higher than the main stacks?

it might be volume (flow rate) rather than pressure that might be the problem.

yeah no mk2 polos came with servo assist. its not whether the valve is wrong its just if its the wrong way round it doesn't do the desired effect.

as long as the valves are nicely on their seats and screwed in correctly then fine, can't remember what the jets sit like on those carbs sorry!

they're on their seats fine, yup.

Swirl pot is next on the list then..

I've had another look at it tonight, and can't find any air leaks. The valve on the servo take off also seems to just be blocked off, unless it's just backwards - but i can't pry it out.

The carb also seems to have no mixture screw, or i just can't find one. That would explain the problem aswell. Just fallen out with age?

Where is the mixture screw meant to be?

The back of the carb, the bottom lip of the mounting flange, looking at it from the passenger side, you should be able to see a hole. Stick a small flat blade screwdriver in there and you should be able to 'locate' the screw and begin twisting.

Brilliant, thanks. I've been looking at the drivers side hole right at the bottom that seems to have nothing in.

It seems just like a brass bung on the passenger side, is that right?

In the install thread, post #55, pic 3, beside the roller for the accel pump, you can see the idle screw. if that doesnt work, pm me an e-mail address, and I'll send you pics of any bit you like from the spare in the garage.

cheers

Iain

any chance of seeing what filters people have used,or how its possible to modify the standard airbox to fit?

i have a weber filter on mine but its falling to bits

Edited 2 April, 200917 yr by herrod

Right, still having issues with mine. I've just not been on it because luckily i have access to another car. Here's what's happened so far.

After messing with the idle mixture screw it idled and revv'd up perfectly, only to stop running properly as soon as i took it for a drive. It would start, rev to about 2.5k smoothly, then die no matter what you did to the throttle.

After messing around looking for air leaks, carb off, resealing etc i decided to swap my dizzy as it had the same symtoms as i have had in the past. It then ran perfectly and revvd cleanly etc. I checked everything was tight, left OFF the vacuum advance pipe because i've been sure in the past that this is why i keep ruining dizzy's.

So as you do i decided to take it for a drive up to the garage about 3 miles away. It drove perfectly on the way up (or as i expected it to at least). On the way back i took the revs up a few times.... revs up, change gear and then nothing again. I had to limp home.

It runs very well at idle, but if you open the throttle on the first stage it will die. If you blip it open and shut it quickly it will go back to idle fine. If you snap open the throttle to the second stage it will reluctantly rev up. I've tried spraying WD40/easy start at idle to check for leaks and the revs stay the same. I've also re-checked/blown through the jets for blockages and they are fine.

Its kind of how it ran before i changed the dizzy, apart from then it wouldn't idle. I havn't got another spare to try, and as i left the vacuum line off i can't see that i have ruined another one by chance (i've used the current dizzy for months without fault)

Thanks for reading...

Any ideas anyone?

Any ideas anyone?

My wild guess (if the coil, spark plugs, ignition leads and all their contacts are uncorroded) accelerator pump diaphragm split.

My second wild guess. You are idling on the progession holes by having the throttle plate slightly open not the idle jet and there _IS_ a blockage in the idle circuit which appears when you rev it. Screw the mixture screw fully in counting the quarter turns. It should be 1.5 to 2 turns out. Remember the turns so you can put it back to the same position. If it's much less than this I'm right, you will need to adjust idle speed back down once fixed too. Unscrew the the mixture screw fully, pull it out (there's a rubber seal so you may need fingernails). Unscrew the idle jet. Blow compressed air from computer keyboard duster spray can through. Replace jet and screw.

Then follow this lean best idle

Edited 10 April, 200917 yr by dvderlm