Why is there 1 carb per cylinder when a car has one carb for multiple cylinders?

Yamaha SRX.

1 cylinder, 2 carbs. And...

Dreadful warm start performance.

 

It was more like one and a half

Mine was ok , apart from when one of the rubber manifolds split

 

butbutbut - didn't Honda build a big single with two carbs at some
point?[/QUOTE]

I don't know about honda, but the SZR660 in my garage has 2 carbs, 1
cylinder, and 5 valves.

 

If you play with your brain too much, you'll go insane.

 

I don't have time to teach you about acceleration loads, I have to go
and help the happy campers at the lake. And, besides, it's already
happy hour over there and your brain is probably already well-impaired.

 

Honda thingy err,, something or other, had a dual-choke carb feeding a
single cylinder. XL 500?

 

OK, enlighten me. A bike will accelerate faster in in first than in
second....

 

Can I have a guess?

Is it because the back load on the gearbox sprocket (and thus rest of
the drive chain) is at its highest, in relation to the power put through
it, on the limit in second?

If by a 1,000,000 to 1 chance I'm actually right the world as we know it
will cease to exist in a puff of illogic, so let's pray I'm wrong as
usual.[/QUOTE]

Interesting point. I dunno. I just can't believe that conrods are
strengthened purely because of second gear. Sorry. Load is load.

 

Someone in the 1970s made an exhaust with a baffle-onna-pivot and a
cable control, so you could open or close it at will. More for noise
than anything else. Wish I could remember who made it.

 

butbutbut - didn't Honda build a big single with two carbs at some
point?[/QUOTE]

Yamaha big singles have had two carbs for years.

 

Alistair Laurie, who used to produce gorgeous Trident specials, would fit a
sort of butterfly valve in his exhausts.

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, Bear

I stand by my point.

And I still want one.

--
Wicked Uncle Nigel - Podium Placed Ducati Race Engineer

WS* GHPOTHUF#24 APOSTLE#14 DLC#1 COFF#20 BOTAFOT#150 HYPO#0(KoTL) IbW#41
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Honda GL1000K2 (On its hols) Kawasaki ZN1300 Voyager "Oh, Oh, It's so big"
Suzuki TS250 "The Africa Single" Yamaha GTS1000 Honda ST1100 wiv trailer

 

Could have been him. Didn't he also make amazing Laverda specials?
Elizabeth's Taxi comes to mind.

 

OK, granted. I remember my old SR too. My 400 Four, OTOH.......

Not to mention a long series of Honda twins. My 1978 CB200 had twin air
filters, one either sid eof the frame, and the filter boxes were
integral with the filter elements - they were just plastic covers.

 

Fine. Go ahead and spoil a perfectly good joke. Would
you have been happier had I said "three or four"?

Bob M.

 

Y'see, this is precisely the problem with trying to inject any sort
of humor into a technical group. The moment you do, SOMEONE
is just bound to trot out the "well, yeah, but didn't Tappet Bros.
Motors, in their 1927 Feeblevitzer model, have an engine which
used a secondary Thelmann wire in the reverse-framistat
confabulator?"

Killjoys. Each 'n' every one o' ya.....

;-)

Bob M.

 

The velocity of the air over each needle in a (small) two carb set-up
should, I think, be faster than the velocity of air over the needle in a
(large) single carb, thus making a more responsive/efficient engine. Its a
bit similar to why big twins (think 916 through 999, Tl-series and SP1/2
plus others) use injection over carbs - to flow enough air at high revs in a
large cylinder, the carbs have to be so big that, at low revs they're
shit.... Use two small carbs and that makes up the carbs opening surface
area at high revs whilst keeping the fast airflow of smaller carbs for low
revs.

Or something

Dave

 

Didn't the Rudge radial valve single have 2 carbs as well?

 

IIRC Yamaha's excuse is that the CV carb works for nice fine adjustment
lower down the rev range and the slide one is for banging in fuill chat
higher up.

Big singles are notoriously finicky things once you try and get any sort
of power out of them - Yamaha actually had to delay the launch of the
XT500 by a year because it was proving such a troublesome engine to
develop, and everything but everything was breaking in testing.

Mind you, it was only the second four-stroke lump they'd built, so they
can be forgiven.

 

On Fri, 16 Jun 2006 07:16:20 +0100,

Eh? They'd made loads by then, shirley? I can think of three twins off
the top of my head: XS1/650, XS/TX500, TX750 (not UK). And I'm not
even sure that the XS750 triple didn't pre-date the XT motor, although
release dates might have been different in different markets.

--
_______
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