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Zenith Strombergs
Anything and everything Vitesse.
Section : Carburettors
Posted By : Stuart Newby, 24-Aug-2006, 03:42pm
Hi chaps/esses
Although they seem fine, I wanted to start from scratch in setting up my twin carbs on my 69 MK2, however they have been replaced in the past with brand
new items, but they don't say "150" on them where it's usually stamped on the top body and the bottoms of them don't appear to have the jet screws on them
like the manual. Instead , they have what appears to be brass cappings at the bases and although they appear to come off by levering with a screwdriver,
when i attempted it petrol started leaking out. There's also slight weeping from the caps and i'm not sure how i can stop it.??
At the stafford show i remember someone saying that i may need a special allen key tool and go in the top via the dashpot to adjust the jets, but i bought
one and popped it in, but it didn't want to turn anything, i didn't want to force it as it felt like it shouldn't move.
Any one got any ideas how to tune these carbs, they are obviously different from the originals...??
I even recently purchased a Moss carb-balancer (air intake balancer) - but can't for the life of me figure out how to adjust it as it seems fixed. The
instructions say undo "A" centric and adjust 'till air indicator goes up half way up the tube but it won't budge, anyone got any ideas of how to use these
things?
cheers all the best Stu.
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Posted By : Peter and Mick Lewis, 24-Aug-2006,
05:14pm
the needle on the later strombergs you refer to can be quite stiff to adjust, these were common in 70s\80s on my tool I drilled and tapped the knurled
knob and fitted two small tommy bars to get better purchase,, you need to locate the small pin into
the slot in the damper slide,, if you dont hold this from rotating you can tear the diaphragm. the brass caps are not to be tampered with as they cover
the base of the jet which does not show like the old styles. the jet position is fixed, the allen key raises and lowers the needle, only adjust 1/8
turn at a time,, rev it a little between adjustments..
not familiar with the the moss balancer on most you need to rotate a vane or shut a throttle plate to get the vacuum to lift the floater or needle to
get a reading,, you need to close yours up bit peter
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Posted By : Stuart Newby, 25-Aug-2006,
02:44pm
hi Peter & Mick
thanks for that - do the brass cappings have any o-rings or rubber washers that may need replacing as they are seeping petrol albeit only
slightly?
Also, when i slot the allen key tool in the top via the dashpots, which way do i turn the key and which way does what?
cheers
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Posted By : Peter and Mick Lewis,
25-Aug-2006, 09:37pm
Stuart this goes back to days when i had a new Avenger without going up to the loft for them old haynes manuals I
believe it copies the old type with adjustable jet ie clockwise rotates the 'nut' in the bottom of the damper bore which raises(rich) the
needle anticlock lowers(weaker) if it is stiff or bloody stiff take the air piston out by removing the top cover and put in vice you can at
least check diaphragm condition as well .... if its grown due to oil contamination wash it in petrol and it should come back to size ok make
sure the positioning lugs are located in the groove on refitting.on the damper and top cover
what specification needles are in these replacements,are they correct for you car ?? guess they will be biased, sprung to keep needle in
contact with the side of the jet.
it was a good idea but does wear the needle sides and the jet bore( not cental like the old ones)
from what i remember the caps are sealed with O rings,, I get all my spares from 'carburettor exchange' in leighton buzzard,
see yell.com they have loads of books and spec sheets and the parts are all available.
dont know how the brass cap is crimped on when repairing the seals,,, dream on peter/mick