Here you go, get a cuppa and settle down to Punnet's guide to fitting Weber 34 ICTs.
ICT DUAL WEBERS
BEFORE YOU DO THOUGH YOU NEED TO CHECK THE JETTING. Idle jets are attached to their holders which is the brass screw to the left of the accelerator pump. Unscrew and pull it all out the jet is attached at the end. It has a number stamped on it...If it is 52 it’s too small. Contact Eurocarb or similar company and get 55s minimum but better 60s. You need two one for each carb.
Second jet is the main. Take the top off the carb carefully and slowly. Don't dislodge anything or damage floats etc. Bottom of the float chamber is the main jet. Look at that. If it is 130 or less you need 135s. You need one for each carb. Get your jets before driving and save a lot of hassle later. It’s an easy job but impossible once the carbs are fitted.
You will have the carbs two mounting brackets (which may be 'handed') crossbar linkage (hex one is best) throttle link and two hemi jointed arms which attach to the throttle links on the carbs.. Do THIS first:
Pre tune; Mixture screw which is sited by itself at the front right of the carb as they sit on the manifolds in the engine bay. Turn right in (gently these parts are not strong) and back out 3 whole turns. That’s in the ballpark.
Next throttle; Get your smallest feeler gauge and tighten the rest of them together again so that the smallest one is 'straight ahead' from the rest. Take first one carb and then the next and do this to both...Open the throttle plate (butterfly) so you can stick the feeler inside the venturi (carb tube) from the bottom of the carb do this at the front of the carb and only stick it in so it holds in place when you close the butterfly back up. Let the feelers hang there in mid air. Turn the throttle stop screw IN until the feelers JUST fall to the ground. Do the other one.
Now this will not be right for your engine but it will be BALANCED. Do it a couple of times if you are not sure because once they are in you'll want them to stay in.
You may need to bend the tinware a bit but after mounting the carbs on the manifold fit the left hand one onto the head. Left hand as you look at the engine! Awkward but it'll go just be patient. You'll find removing the no3 spark plug cap to be essential...In fact you might want to change all the sparkplugs while you are at it as it will be more difficult later on...
Tighten her up so she's sat in place. You may find on some manifolds you need to 'modify' the fanshroud a bit...use a rubber mallet or similar to create a little extra room...you don't need much. Newer manifolds are taller and don't have this problem. On single porters use type three single port manifolds. The manifold spurs are for the balance pipe and are essential for smooth running whether you use vacuum take off for the dizzy or an 009. If you have the standard small twin port manifolds you need to drill and tap for balance pipes. You can get the spurs from Eurocarb to do this and the point to drill is marked by a raised blanking bit on the manifold. You see each manifold has two you only drill one so the balance pipe is to the rear of the fan shroud.
Attach the fuel line and tee piece to the carb and fuel pump (I take the pipes round the back of the fan housing and the one from the fuel pump over the top. Use 'crimping' fuel line clamps not jubilee types...they are easy enough to get for 5mm hose not so easy for 7 though. If you can’t get the crimping ones get the ones where no moving parts come into contact with the pipes. Also check that the lines do not get near the thermostat control spring...you'll just have to feel for that...should be fine I haven't had a problem yet.
For 009 dizzy use:
At the same time (important bit this) attach another short piece of 5mm fuel pipe to the port that is strangely unused on the outside of both carbs. Block both up with a small screw and washer. Get a good seal.
For stock dizzy use:
Block off the right hand carb vacuum port and take a pipe from the left hand one to the dizzy vacuum can. An in line anti pulse valve will help (available from Eurocarb) but is not essential.
The vehicle will be more drivable and run cooler with a stock dizzy. The only advantage with an 009 is that you get slightly more zoom at lights...but in a bus that is hardly important. You'll also get more unwanted heat when climbing hills and going down the motorway. The vacuum pipe ought to be long enough to go up to the carb from the dizzy to prevent any possibility of fuel reaching the rather fragile vacuum diaphragm.
Join the balance pipe to each manifold spur and secure. This needs to also be air tight and otherwise will create air leaks and fuel leaks.
Cable tie both pipes (fuel and balance) together and secure away from the fan and the vanes linkages.
Set up the linkage and attach to left hand carb.
Fit RH carb to manifold and fit fuel and balance pipe lines in place.
Fit it to the head allowing for the crossbar to fit in place. A little dab of grease on the end joint helps.
Tighten everything up and check it all again and again just in case. Especially fuel lines. The only bits of fuel lines I fit with screw type clamps is the ones on the carbs themselves in case I want to pull them quickly.
Fit throttle cable and watch the angle. It needs to pull in quite far to get full throttle.
Now the other important thing, Throttle return springs; I don't know who designed these but they are terrible!!! You will note that if you put them on where you are told to they pull the arms UP but not ACROSS to the stop...So you all fit ingenious spring systems (some quite amazing looking) to pull the throttle back to the stop.
Do this instead: Get two stock Solex carb return springs (same as for the Bocar) and fit them into the holes on the throttle arm and on the left carb to the hole on the angled bit of the mounting plate against the fan shroud....There is a hole there strangely if you look at the bottom of that part. On the RH carb there isn’t as it is the other way round (not handed) so you either drill a hole or simply hook the return spring into the angle where the plate changes shape at the top of the mounting section on the carb. Does that make sense? There is a horizontal bit then it changes twice to go vertical to the crossbar linkage...use the first angle. Works a treat and closes off the throttle. The throttle is lovely and soft then and not a pain to keep on the floor. (You may need to bend the accelerator stop tab up to get more throttle but NOT on automatics!!!!) Helper springs which are round and work with the movement are helpful strangely but with the EMPI and Bugpack systems difficult to fit.
Set the arms up roughly (just through the top holes and don't put the nuts on) and start her up. A couple of blimps on the throttle will get her going.
Far too fast? Usual. Turn her off again and get round and take off the arms and screw each throttle stop screw exactly the same...say a full turn and do it again (arms pushed back it) until you get a sort of fast tick over. Make sure it is done evenly. Don't get this bit wrong or its carbs out again and start all over (well perhaps not the mixture again) It’s a pain I know...but worth it.
Leave it running and get round the back and pull the arms off again. This is so that the carbs react individually and you can tune them separately.
Set the mixture. Presuming she's warm move the mixture screw in very slowly till the engine note DECREASES (it may increase slightly at first) and then back out even slower till it settles at its fastest point. Blip that carbs throttle slightly and do it once more...then its set. Do the other. Set the idle speed once more to the tick over you want (850 revs or so) by adjusting both carbs equally and then turn her off. Put the arms on properly (ie get the nuts on this time).
Set the linkages up so that you get both carbs at stop at idle. Remember they each affect the other if you get what I mean. You will need to run the engine to get the final tweak done.
Get someone to stamp on the accelerator pedal while you watch and see that both carbs open evenly and you get full throttle. Engine back off for that one please don't want to annoy the neighbours. Don't do it too much as fuel will be entering somewhere and there is a chance it may get down into the oil!!!
You'll find the whole thing will 'settle' down over a few drives and you may have to reset the arms again but not the mixture!!! And don't 'experiment' with the throttle positions or you'll have to start all over again. What you do to one carb you must do to the other.
You'll notice as you set the arms that there is a sort of 'relaxed' space between the operation of one side and the other. You need to get in the middle of this.
Hope this is useful. If you are getting a professional to fit them give him/her these notes...not to insult them but to help with the crap instructions that come with the kit! Otherwise they may think it’s the carbs that are crap and they are not...well the casting could be better and so could the kits but the CB Performance kits are a bit more expensive (although correctly jetted and fits better and....).
