Welke sproeiers in solex H30/31 ?

[Mispoes]

ok, maar nu weet ik nog altijd niet welke sproeiers er in mijne carbu horen te zitten? :p

[danimieghem]

goegelt nekeer ????

[eric vh]

dat heb ik hem ook al gezegd ze vandemorgen

[Mispoes]

30 PICT and H30/31 Carburetor Jetting

We can only give a guide here, as engine age, type of fuel, carburetor wear, etc. all make a difference in how our old engines run, so you might need to experiment a little.

For information -- the 1200cc engines originally came with a 28 PCI or 28 PICT carburetor, both of which have a 22mm throat. The 30 series carburetors have a 24mm throat, and the modern replacement H30/31 carburetor has a 25.5mm throat. The 30 and H30/31 carburetors were designed primarily for the 1300-1600cc single port engines, but you can get slightly better performance with the larger carburetors on a 1200cc engine, but only if they are set to run properly with the smaller engine.

The standard jetting that the 30PICT/1 & 2 carburetors came with is size X122.5 or X125 main, size 55 idle, and size 125Z air correction jets. The 30PICT/3 and the H30/31 carburetors came with size X112 main (super lean), size 65 idle, and size 125Z air correction jets, which made them very difficult to tune. The larger size 65 idle jet helped the 30PICT/3 and H30/31 carburetors overcome the very lean main jet at idle and low speeds, and thus help to reduce the "bogging" problem.

When using the 30PICT or H30/31 carburetor on a twin port manifold and any vacuum distributor, change the jets to X125 or X127.5 main, 55 idle, and leave the air correction at 125Z. Try the X125 main before you try the X127.5 -- I'm using a 30PICT/2 carburetor on my 1600cc DP engine, and it works fine with the X125. But engines do differ a little, and the sizes above are "ball park" figures rather than definitive.

Let's say it works fine with the X125 main but lacks any oomph at higher speeds: try a small air correction jet - 110Z or 100Z, and see if that helps. (See the discussion of the air correction jet above.)

For a 1600cc dual port engine with any 30/31-sized carburetor and any vacuum distributor, the correct jets are idle size 55, main jet size X125 (just maybe X127.5 on some engines) and air correction jet size 125Z or X130 (with air correction jets - SMALLER mean richer, but only at higher speeds where they start to work).

If you live at altitudes above 5000 feet, you also have to consider that, as high altitude results in the engine running rich (less oxygen in the air but the same fuel flow through the carburetor). It this case you would definitely need to reduce the main jet size to say the size 122.5 or the 120.

On the H30/31 carburetor, there are two brass jets on the right side (right is right of car). The angled one (points slightly towards the rear of the car) is the idle jet. The other one (pointing straight out to the right side of the car) is the power jet, which feeds additional fuel at high throttle/high rpm. The power jet is needed to correct a tendency for the air correction jet to work TOO well at max airflow - it leans the mixture off too much and the power jet corrects this.

If you look at the two jets you can see that the idle jet sits in a protrusion (which has a vertical gallery drilled inside) which continues downwards under the jet, towards the idle fuel ports in the throat near the butterfly. The power jet sits in a protrusion which extends up to the top of the carburetor where the delivery tube sits in the top of the throat.

The idle jet is usually a size 55 (when the main jet is normally a size X125 or X127.5) but it might be a size 65 if the main jet is a X122.5 or smaller.

With the larger main jet, you might also need to consider a size 50 idle jet in lieu of the normal 55. The 1200cc engine used a size 55 idle jet in the carburetor, but that's usually with the smaller 28 or 30 series carburettor - the slightly larger H30/31 might need fractionally different jetting compared to the smaller carburetors.

The power jet is usually a size 65. In most cases you can just leave the power jet alone. It only works at full throttle and high RPMs – the size 65 power jet should work fine for those conditions.

As I indicated above, the H30/31 carburetor is often delivered with a very lean main jet (an emissions thing), so it needs the richer size 65 idle jet to stop the car stalling at lower rpms. If it has the small main jet, then you'll get better performance and easier tune-ups if you change it to a size X125 (for 1200/1300/1500cc engines) or a size X127.5 (for 1600cc engines) and change the idle jet to a size 55.

Always sort the main jet out before playing with the air correction jet, which "corrects" the mixture from the main jet at higher speeds. If it seems a little rich at higher speeds (plugs sooty after a plug read) then try the 130Z air correction jet.

I've been running my '68 Bug with the X127.5 main jet in the smaller carburetor, and he's running a tad rich. The exhaust system peashooters started turning black inside as soon as I put the larger jet in. I haven't run enough through the tank to get a real idea about consumption yet, but since I don't notice any huge difference in performance I'll probably be going back to the X125 soon. Useful experiment anyway.

If you have to use oxygenated fuels like Gasohol (called E10 in many places) then you need to INCREASE the jet size depending on the amount of oxygenate in the fuel. E10 usually needs a larger main jet and might also need a larger idle jet.

Some tests to help you determine proper jetting. Take the car for a run at a modest speed - say 35-40mph. Use a steady throttle - minimum acceleration. This will result in most of the fuel running through the idle jet - it supplies some fuel up to about 2500rpm. Then remove a spark plug and read it (see our Spark Plug Reading Guide). A sooty plug means the idle jet might be a little large. A clean plug with a light grey/tan look means the mixture is about right. The try the same test at a higher speed - a steady 55-60mph. This will have the main jet supplying the fuel, and read the plug again. Soot will indicate the main jet is a little too large.

If you have a 009 (centrifugal advance) distributor, you may find that the spark plugs still seem a little dry/burnt looking at medium speeds , or the car lacks acceleration in the mid ranges. If this is the case, try a larger size main jet -- size X127.5 1200/1300/1500cc engines. It should not need to be bigger than that with a vacuum distributor (009 distributors need richer mixtures). For 1600cc engines, use an X130 main jet. In both cases, when running the 009 distributor, set the accelerator pump for maximum squirt.

Once you have those two sorted, then try a faster run and from 60 try flooring the throttle - if you get a good smooth response the air correction jet should be OK, but if it tends to stumble a little or feel breathless, then either the main jet is a little small or the air correction jet is a little large.

None of these tests are definitive - just indicative. The only method of getting it exact is to run the car on a dynomometer with an exhaust gas analyser in the exhaust pipe.

------------

toch nog iets gevonden dus , nekeer ontcijferen ze, tis ne gansen boterham :p

bron: http://www.vw-resource.com/jets.html#30

[eric vh]

http://www.vw-resource.com/jets.html#30

[eric vh]

dus ik lees als ge nen 009 hebt dat ge andere sproeiers moet steken of uw motor loopt 4kant en geeft tekenen van te rijk te staan droge zwarte bougies enz.

[eric vh]

dus daar steekt het hem dus ahaaa dani we hebben hier iets gevonden ze

[Mispoes]

accelerator pump for maximum squirt




X127,5 main jet
120 <- nu

80-100Z air correction
125 <-nu

size 50 idle jet
50 <-nu

The power jet is usually a size 65
65 <-nu


voila, dat is het zowat ontcijferd
duuus: men hoofdsproeier is te klein en men rolantiesproeier is te groot, en dit kan vuile bougies en hoge co verklaren mss...

[beestje]

op een 1300, zit orig een solex 31 pict-4 op !! serie 113 129 021 L

sproeier-venturie 25.5
combinatie hoofdsproeier X 130
Remluchtsproeier 110 Z
stat.benzinesproeier 52.5
stat. luchtsproeier 100
extra benzinesproeier 45
extra luchtsproeier 150
vollastsysteem met / zonder kogel 2 x 100 zonder.
opbrengst acc.pomp , kubieke cm/slag boven +20°C; 1.15-1.45
onder +15°C; 1.8-2.2
vlotternaaldzitting mm 1.5
pakking onder vlotternaaldzitting 1.0.
vereist octaangetal 91. stat.toerental 750-900
co-percentage 2 - 4.

dit is een solex carb, en zo moet hij uitgerust zijn.

de afstelling, is een ander hoofdstuk..

[Mispoes]