Guys
Now I have fitted a 32/36 Weber to my 2 litre Pinto, I am having problems in setting up the carb to run well throughout the rev range. The camshaft is a 270 Piper, which is a mild-tune for un-modified engines.
Originally, the engine had a 38 DGA Weber from a 3 litre Grannie, and for thos who might have followed my messages on this, it was a bit of a pain for regular road use. So I took the plunge and bought the model the engine had originally, brand new, from Fast Road Cars. The guy there is very helpfuly, but so far I haven't resolved the snags.
When I first ran it, I had to screw in the mixture screw to only half a turn from fully-home position, instead of the usual 1-2 turns. As an experiment, he said to swap the idle-jets over Primary to/from Secondary. These were 60 primary and 50 secondary size.
To cut long story short, I've swapped over the jets from the 38 Weber, and now am running with 45 Primary and 50 Secondary. The tickover is better, and it cruises OK at speed, but there is a dreadful flat-spot at around 1,000rpm. This makes for a piggish problem in traffic.
Has anyone established satisfactory idle-jet sizes on a 32/36? I think the 45/50 combination is per Haynes, but they are not always correct?
I'm also wondering about the accelerator pump, and whether it is pumping enough fuel into the primary choke at the right moment. It might account for the flat-spot, when the engine almost dies is the clutch is let out slightly too harshly. Usually means that revs have to be nearer 1,500rpm to guarantee success.
Cheers
Mike
Now I have fitted a 32/36 Weber to my 2 litre Pinto, I am having problems in setting up the carb to run well throughout the rev range. The camshaft is a 270 Piper, which is a mild-tune for un-modified engines.
Originally, the engine had a 38 DGA Weber from a 3 litre Grannie, and for thos who might have followed my messages on this, it was a bit of a pain for regular road use. So I took the plunge and bought the model the engine had originally, brand new, from Fast Road Cars. The guy there is very helpfuly, but so far I haven't resolved the snags.
When I first ran it, I had to screw in the mixture screw to only half a turn from fully-home position, instead of the usual 1-2 turns. As an experiment, he said to swap the idle-jets over Primary to/from Secondary. These were 60 primary and 50 secondary size.
To cut long story short, I've swapped over the jets from the 38 Weber, and now am running with 45 Primary and 50 Secondary. The tickover is better, and it cruises OK at speed, but there is a dreadful flat-spot at around 1,000rpm. This makes for a piggish problem in traffic.
Has anyone established satisfactory idle-jet sizes on a 32/36? I think the 45/50 combination is per Haynes, but they are not always correct?
I'm also wondering about the accelerator pump, and whether it is pumping enough fuel into the primary choke at the right moment. It might account for the flat-spot, when the engine almost dies is the clutch is let out slightly too harshly. Usually means that revs have to be nearer 1,500rpm to guarantee success.
Cheers
Mike
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