Twin carbs and starting

Discussion in 'Mech Tech' started by mrflib, Feb 4, 2024.

  1. Hello all

    I've got a 2l auto late bay and we bought it with twin carbs fitted. Rolling road test showed they were perfectly tuned.

    However I am in no way mechanical minded - learning as I go - and it is my understanding that the carbs make it hard to start from cold.

    In terms of hard, it takes 5-10 mins in the summer of me flailing about to get it going and in the cold... 30 mins plus. Makes me feel like a bit of a pillock on a camp site when I have to leave in the morning and people are still sleeping. Well they were sleeping until I tried to start the bus hah!

    I have no doubt I'm being crap, but we had hoped to rent it out a couple of times to help with the cost of ownership. There is no way we could do it with just how hard it is to start.

    Does anyone have any tips or ideas of additions/ modifications / technique to get this starting better? I'd really like to keep the carbs as we go to hilly places and I understand it helps with fuel efficiency.

    Once it's warmed up and the fuel is running it re starts like an absolute dream.
     
  2. MorkC68

    MorkC68 Administrator

    What carbs are they?

    Solex
    Weber
    Dellorto
     
  3. Zed

    Zed Gradually getting grumpier

    What carbs?
    What did the rolling road actually test? WOT is the usual for safety (of your engine), but few will bother jetting the idle. Generally small idle - hard to start, big idle easy to start but not so efficient.
     
  4. I think they might be weber I took a photo I hope that helps.

    The rolling road guy checked for balance - I was sent there by a mechanic when I first got it home for no reason but to check and get a base for the future.

    Sorry guys I'm not up to scratch on all this![​IMG] [​IMG] [​IMG]
     
  5. 10-15 seconds of feathering the throttle is usually enough for twin dells .
     
  6. By the sound of the symptoms, it just sounds like choke isn't closed to me

    A simple fix on Solex carb, but I don't know anything about the carbs in the pic here.

    I have a 2lt auto too, and choke is really important on our Autos.

    Do these carbs have an electric choke ? Or even a manual choke ?



    Sent from my SM-S908B using Tapatalk
     
  7. It is my understanding the choke is removed for these carbs... I think.
     
  8. MorkC68

    MorkC68 Administrator

    Where the carb bolts to the manifold, does it look like a bolt is missing?

    upload_2024-2-4_15-6-50.jpeg

    It’s on the outer bolt, the hole is visible.
     
    nicktuft likes this.
  9. It's likely you don't have chokes - any sign of cables/choke control?

    On my Dells, three pumps on the pedal to get some fuel squirted in, then feather it until they clear their throats. As they're on short manifolds, the carbs warm up pretty quickly.
     
    The Bobdogs likes this.
  10. They look like CB Performance manifolds and the stud is more likely to have fell out .For some reason they have very course badly cut threads from new .
     
    Lasty, snotty and MorkC68 like this.
  11. MorkC68

    MorkC68 Administrator

    I thought so too!

    That’ll not help matters.
     
    snotty likes this.
  12. It’s probably fallen out that big hole in the tinware.
     
    Huyrob, scrooge95 and MorkC68 like this.
  13. Lol
     
  14. Ah well that sounds sub optimal.

    We were considering getting a new engine put in from the VW engine company. Might be best I just ask them to take a look when I go to get a quote!
     
  15. Why do you need a new engine? Stick with what you've got!
     
  16. docjohn

    docjohn Supporter

    Has anyone said that they are Dell'Orto FRD carbs? It also looks as though there is an adapter to rotate the carbs by 90 degrees. That may be a normal thing to do, but it will make adjustments harder as access to the linkage looks awkward.
     
    paradox likes this.
  17. I am sure your engine is fine. Just speak to them about those carbs, either they need a choke setup, or tuned, or replaced. Your auto box and the original 2 litre engine go nicely together.

    Sent from my SM-S908B using Tapatalk
     
  18. Don’t do that
    A bit of time learning and going through things step by step could save you a lot unnecessary expense.

    Where are you located?
    We may have a member near by who would be willing to take a look for you
     
    docjohn likes this.
  19. Does it stink of petrol in your engine bay?
    It looks like one of your carbs might be leaking fuel

    IMG_0387.png
     
    docjohn likes this.
  20. It does smell of fuel when I drive it was one of the things I wanted them to look at!

    The new engine was for rental purposes - we are using it for weddings!
     

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