Evening all, I'm after some thoughts on the possible cause and ideally solution to a problem Hoot has developed. She is fitted with a type 4 1.8 later engine fitted with a weber progressive carb and 109 distributer, both fitted in the USA by a previous owner. She's always been a little hesitant on pulling away, but I put this down to carb, but just recently it's become a problem with the engine stalling as I pull away. The bus even struggles to pull when it change down, instead kangarooing briefly before pulling properly. The only way round the problem seems to be giving the engine loads of revs and slipping the clutch. Once moving she pulls happily all the way up to 70 Any ideas? Thanks
Mine did something similar to this was to much fuel /air in the carb read up on it and set up as per manual,pulls at low revs now like a choo choo !!
what daisy said, sounds a bit like it might be leaning out a bit. check all the boots for cracks and splits, it might be drawing in air. when did you last adjust the valve gaps? was there much adjustment needed??
Is this only whilst cold, or is it a problem once the engine is properly warmed up too? Ours did it when cold only - and was resolved by replacing the thermostat which had failed and would not expand.
prog carbs need setting up properly or else you'll get a certain hesitancy at low revs....the stock jetting is a country mile out to account for the fact that most folk don't bother to reinstate the factory pre-heat air intake and fit the pancake filter instead....009 dizzy likes to be revved....no vac advance at idle and transition off idle means you have to lead boot it to get the ignition advance to where the fuel air mix at the time would burn best....hence the stumble.... people have tried bigger pump jets, bigger primary idles, smaller primary idles, different air correctors you name it....the bottom line is the single inlet and carb needs heat, before any meaningful jetting and adjustment can be made....without heat your p*ssing in the wind
Thanks guys, so is the general opinion that the ideal option would be to ditch the progressive carb and fit twin carbs, correctly jetted?
