Tuning boxer twin Weber 40 IDFs myself - Easy? Possible? U..

I think you may well be wrong about them turning. There's quite a lot
of
vibration, and not a whole load of positivie locking. Can't see why
the
linkage won't wear either.

In any event, every straight 4 I had ran noticeably smoother after a
balance, particularly at idle, and they woudl idle rougher after about
6
months. YMMV of coruse

I have to agree with Catman on this one, I had a 1500cc Sud Ti, & a
2000GTV Although they had Dellortos they adjust the same as the Webers
and you may have to reset them at least once a year.
You have to make sure the linkage opens all butterflys at the same time
via the adjustment screws on the small cams. Gunsons do a cheap but
handy gauge with a tube to balance these carbs, you have to hold the
gauge onto each inlet port and take a reading then adjust to get them
all the same.
To adjust the mixture I used to screw in all the mixture screws then
unscrew out 2 full turns. start the engine, Then with my ear to each
port in turn, I would listen to the engine note for the smoothest
running while adjusting each screw back and forth slightly, then after
a good road test I would check the colour of the spark plugs. If they
were light grey the mixture is too weak, if they were brown to black it
was too rich. But if the engine note was smooth while checking, it
would probably be spot on. Maybe a slight turn to each to get the Co
exact at the MOT station.
John, UK.
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"Catman" <catman.TakeThisOut@rustcuuore-sportivo.co.uk> schreef in bericht
news:EM87g.346639

> IME carbed Alfas like to be balanced every 6 months or so. At least ours
> do. Having said that, £70 sounds like a lot

What? Once balanced they should be ok for ever. How do you think they go out
of balance, the linkage doesn't wear and the screws don't turn by
themselves.
I bought a set of 4 vacuum meters years ago for like 40 euros and I only
have to balance the carbs after major work like when the cilinder heads were
off.
It is possible that the jets are blocked by dirt especially the stationary
jets, take them out and blow them clean with compressed air. If the car is
not driven regularly the modern fuel affects the aluminium of the carb
housing, at least I think that is the cause.
If CO is to high at a test and the car runs ok, just turn in all the 4
mixture screws by 1/2 turn or a full turn. But a CO of >3.5% never ocurred
to my cars, they were always below 1.0% even when tuned for maximum
performance.
For my Sud I'm preparing a 16 valve 33 engine right now. Making manifold
adapter for carbs, making new large airfilters for each carb, making exhaust
manifold that clears the brake discs, no cat of course, should make 155 HP
when done but a lot of work.
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Bert Kanters wrote:

>
> "Catman" <catman.DeleteThis@rustcuuore-sportivo.co.uk> schreef in bericht
> news:EM87g.346639
>
>> IME carbed Alfas like to be balanced every 6 months or so. At least ours
>> do. Having said that, £70 sounds like a lot
>
> What? Once balanced they should be ok for ever. How do you think they go
> out of balance, the linkage doesn't wear and the screws don't turn by
> themselves.

I think you may well be wrong about them turning. There's quite a lot of
vibration, and not a whole load of positivie locking. Can't see why the
linkage won't wear either.

In any event, every straight 4 I had ran noticeably smoother after a
balance, particularly at idle, and they woudl idle rougher after about 6
months. YMMV of coruse

> I bought a set of 4 vacuum meters years ago for like 40 euros and I only
> have to balance the carbs after major work like when the cilinder heads
> were off.
> It is possible that the jets are blocked by dirt especially the stationary
> jets, take them out and blow them clean with compressed air. If the car is
> not driven regularly the modern fuel affects the aluminium of the carb
> housing, at least I think that is the cause.

Not really a huge with most of the fleet now

> If CO is to high at a test and the car runs ok, just turn in all the 4
> mixture screws by 1/2 turn or a full turn. But a CO of >3.5% never ocurred
> to my cars, they were always below 1.0% even when tuned for maximum
> performance.
> For my Sud I'm preparing a 16 valve 33 engine right now. Making manifold
> adapter for carbs, making new large airfilters for each carb, making
> exhaust manifold that clears the brake discs, no cat of course, should
> make 155 HP when done but a lot of work.

An equal amount of fun, I would expect

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 >> Stay informed about: Tuning boxer twin Weber 40 IDFs myself - Easy? Possible? U.. 

All set up correctly now, 1% CO, a much crisper exhaust note and
plenty of pop on overun!
 >> Stay informed about: Tuning boxer twin Weber 40 IDFs myself - Easy? Possible? U..