Weber Carb

[Buzz word]

I have an old set of weber twin 40 dcoe carbs i bought from ebay for my kit car. When i bought them the carbs were in need of attention and had clearly been left to sit for some time as made evident by the orangey goo in the carb that i assume used to be petrol once upon a time. i cheaned them up and reassembled them. last week i had a chap over to try and tune them as whatever i tried didnt seem to work. The engine is a standard pinto 2.0. Ignition is sierra based dizzy with elec ignition. idle advance @ 8 BDTC.
choke-32

aux choke-4.5
pump-40
idle-45f9
air cor-180
emulsion-f16
main-135

engine advances ok and all plugs are definatly firing.

With those stats i feel the car should work fine and so did the tuning chap. The issue is that it just wont. it wont hold the rpm heigher up the range. after the revs have built up and the extra fuel from the pump jets is burnt the revs just die and the engine stalls.
he said, and im inclined to belive him, that the internals must be blocked or impaired. i have had an offer to have them ultrasonically cleaned but this obviously means totally stripping the carbs down and then refitting to see if they are fixed.

Before i go through this hassle i figured i would ask if anyone could say for a fact if this will work or not? i dont know what else the problem could be or how to check the carb for any other faults? i see the only other option as getting hold of another set but this obviously is going to cost alot of money!

[grahambell]

Hi Buzz,

Once had a similar problem with a set of used 40s. When I stripped them down there was so much muck in the bottom covers you could have grown carrots in them.

Anyway, cleaned up what I could see but the car just wouldn't run right - would accelerate OK once then run like crap.

Finally resorted to drilling out all the little lead plugs for the small internal ports, using a very small drill (finger turned) to clean them out - and yes, they were blocked. Then injected white spirit down them with a syringe to make sure they were all clear.

Re-plugged the ends, put everything back together and it ran fine after that.

So looks like you've got some unblocking to do.

[Buzz word]

Hi graham,
i sorted the problem, gacve it a full strip down and found no issues. drilling passed carb cleaner all the way through and welding wire passed through the progression drillings and mix drilling. i went to speak to a chap at mowatts who told me the older 'holbay' webers without the hole in the front use different top caps. the older ones have a castelated spacer to vent. i nver knew this but there was probably a good 30 min chat before we got here so i dont feel too silly. about 3hrs later i had both carbs fully rebuilt and a free reving engine.
bloody fustrating the amount of work i went and put in for such a simple fix. i suppose you could say it was a blockage but was one i made. quite agravating but now fixed.