Took ICT34s apart...

Discussion in 'Mech Tech' started by SkutterBob, Mar 20, 2015.

  1. Three or four different ones on there, cant remember which i got, this is one of them 370597327209
     
  2. Do you have a lathe keith?
     
  3. Just double-checking, these fit Weber ICT 34s?
     
  4. No, unfortunately
     
    paradox likes this.
  5. Most of the bushes seem to be 8 x 10 x 10 so it might be worth checking your carb first
     
  6. OK, got the new Filter King fitted at 2psi and took it for a run to a local club meet. I got 5 miles of no problems before there was misfire. Then ran smooth, then did it again. I stopped at a nearby pub and the engine cut out and would not restart. I checked for fuel in the regulator glass bowl, and it was full. I took one if the pipes off and fuel also dribbled out. I was just contemplating it was an electrical fault when I got it started.
    I carried on into Norwich and it seemed OK, but with a noticeable flat spot. I think I have the fuel pressure too low and will adjust it later.

    After getting back, I checked the engine bay and both carb upper gaskets were wet with fuel. So changing the regulator has done nothing to fix the issue. I am stumped now. Do I have faulty carbs? I have re-checked the float levels and the needle valves and all is fine.

    I might have to get a garage to look at it. :(
     
  7. mikedjames

    mikedjames Supporter

    Could be the new needle valves are shorter than the old ones so they cut off with higher fuel level. As there is a lever involved , 1mm at the valve means maybe 10mm level at the float.
    Also is there meant to be a spacer washer under the needle valve which has gone missing. This would also mess up the float height setting..

    or a missing copper washer under the needle valve may just result in being unable to seal the valve to the carb body.

    when the needle valve on my progressive went it was when I stopped after a mile or so that the engine flooded and would not start once the choke popped off so the fuel consunption dropped. Before that there were odd shudders when cruising down hill at 30 in 4th..
     
    Last edited: Jul 9, 2015
  8. I have been emailing Eurocarb and they say that the gaskets do get wet during normal operation if the carb. It is not dripping anywhere - seems odd to me.
     
  9. Would that be the Eurocarb who tell you their new carbs are jetted correctly ??

    :rolleyes:

    Taken with a pinch of salt maybe ...

    :hattip:
     
    Paul Weeding likes this.
  10. Here is a picture of the left carb, just after I took the top off. You can see the front half of the gasket is wet with fuel. I would have thought it would all be wet if the float was too full.

    [​IMG]
     
  11. During last week:

    • Swapped float needles and seats with old carbs (which were recently replaced when I rebuilt them). Still leaked around gasket.

    Today:

    • Swapped the tops of both carbs with my old ones - still leaked
    • Took apart my old carbs and fitted the spindle seals only to find out there are no bushes in ICT34s. It looks like what I thought was worn spindle bushes and from information gathered from other websites discussing the subject turns out to be just worn spindle seals. I had some spare from the rebuild kits so fitted them. The amount of movement in the spindles is just the same as the new ones.
    • Removed new carbs and swapped back float needles and seats. Swapped about jets to make old carbs correct and fitted them still checking the float height was about 6.5- 7mm.
    • Tuned old carbs and got the bus running pretty sweetly after following Punnet's car guide (quite pleased with myself).
    • Took bus out for a run only to discover the old carbs now leak in the same way as the new ones!
    So now I have two sets of ICT34s, both making their gaskets wet with fuel, £250 worse off, got a spare set of working carbs, and no further forward.

    It is not dripping fuel down the carbs, so still OK to drive - just annoying.

    I am going to buy two new float needles and two sets of gaskets just in case the old ones have got really useless because of all the swapping about.

    If still no joy then it will have to be looked at by someone who knows. It has to be something I am missing. My fuel regulator is running at 3psi.
     
  12. Zed

    Zed Gradually getting grumpier

    From experience that's on the high side. I'd say 2.5 max. Try 2 or even 1.5 if it's one with a dial.
     
  13. Zed

    Zed Gradually getting grumpier

    How are the carbs plumbed? In a chain, or T'd off to each carb?
     
  14. @zed - T'd off. At 2psi, I had a horrible flat spot, so could wind it down to 2.5psi.
     
  15. Zed

    Zed Gradually getting grumpier

    The time you would notice lack of fuel pressure is foot to the floor up a long hill. What sort of flat spot?
     
  16. Hesitation when first accelerating + it started to splutter and stalled easily.

    I have a fuel cut-off solenoid near the tank. You don't think this is causing an issue? It has 10mm outlets, so I had to put conversion pipes in to step up to 10mm and down again. I got it from a diesel specialist.
     
  17. Zed

    Zed Gradually getting grumpier

    That could be over-fuelling too. To save me reading back through 4 pages, what emulsions do you have?
     
  18. If I push down on the upper spring bracket, I can squeeze fuel out from the gasket.

    [​IMG]
     
  19. F6s
     
  20. Zed

    Zed Gradually getting grumpier

    Hmm. Maybe they've been over-tightened, the screws are all kind of near the middle. Fuel will be jiggling about in there, I suggest that's all your problem is - a poor fit.
     

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