WEBER TWIN 40 DCOE

[dansdad]

hi all , i wonder if anyone can give me a bit of advise , i have an early mk2 with weber 31's , and i have tried allsorts to set them up, i downloaded a list which gives the standard jet sizes which were used on the standard engine, the special and the big valve , mine ,i think is the standard , the problem is that it continually soots up the plugs ,(too rich ) , i have put smaller main jets in , and larger air correctors , smaller idle jets , and smaller accelerator jets ,, it dosent run too badly with this setup ,but clogs the new plugs within a short time ,, i did forget to mention that it has been given big valves when the engine was rebuilt , so the next step , i thought would be to put 32 mm chokes instead of the standard 30mm , but changing them on these older carbs isnt quite as easy as in the videos ive seen on youtube,, any ideas please ,, any help is much appreciated , jeff watts

[ray8829]

Have you checked your float levels as they can affect the mixture?

[dansdad]

hi ray , yes thats all fine . 8.5 mm with the gasket,

[MagnusHolmgren]

Hi
I had mine on a rolling road recently. 12% more BHP and the same increase in torque.
I highly recommend that. Even though mine isn't 100% perfect it is way better than before. Mixture is still a bit too rich, but I will go there again when I have a new exhaust fitted. I don't know about the prices in the U.K., but I payed about the equivalent to £160 for 1 1/2 hour. I thought that was a good price.
The guy changed the low speed jets, other than that only adjustments, carburettors and ignition.

Magnus

[dansdad]

hi magnus , i took mine to a fella with a rolling road near to me about three years ago and asked him to sort out the carbs , as i had recently had the engine rebuilt , unfortunatly he was a specialist with modern cars and most of his work was done via a laptop , he had the carbs in peices for over 12 months , and got it running the best he could and gave it back to me , he was too embarrassed to charge me anything , and so i set about doing it myself ,, with some success , but just need to lean it off ,, i think that changing the choke to the next size up is worth a try , . i have now found out how to remove them without damage ,so will try that

[jwoch]

Are you sure that its petrol soot fouling?
Could it be bore/piston wear giving oil carryover and fouling?

[L2Man]

PM

sent

[dansdad]

sorry for the delay in replying, im quite sure it is petrol , the engine has recently been rebuilt professionally with the bores being honed and new rings fitted , an update , i have now fitted larger (32mm) chokes and it has made a real difference , and i was able to put larger main jets in , and plugs are slightly discoloured , and she is running lovely now , thanks for all the advice