Newbie Question about performance

Quick question for anyone who knows anything about motorcycle
mechanics.

"Speed's just a question of money. How fast can you go?"

Can replacing a carburetor with one from a bigger engine increase the

Yes, get the carb off the biggest bike you can find, ones from twins go
particularly well on fours (you just need to prise them off 2 bikes).

At the same time go and ask your local bike dealer for a set of race jets,
these are extra slippy and allow more fuel across them.

performance of the bike? A friend suggested it to me, but I'm not

Better if you don't bother taking the carb off the bigger engine at all and
just put them both in.

What's the beastie in question?

quite sure if I believe him, so a more reliable opinion would be
nice.

IMHO it's not something to be attempted lightly. Assuming it bolts
straight on it'll still have to be professionally rejetted. You may
get more top-end power, but at the expense of torque at lower revs.
Plus you'll need to declare it to your ins. co. which may put up the
premium.

Yes, but it depends on the bike. The simplest way to increase power on a
Nordwest is to replace the OEM twin choke (one slide , one CV) Teikei
carb with two Keihin CR smooth bores. They need setting up though.

On little 50cc auto MX bikes a bigger carb it is a quick tune up route
too as they are often very small in novice trim.

Generally though, as others have said, I wouldn't recommend it to a
newbie.

If you're talking about a bike with one carburetor, then you're dealing with
kit at the very bottom of the performance food chain, and, honestly, wasting
your time. You don't say what your bike is, or whether you've got a full
licence. If you're a learner, the quickest and most sensible route to more
performance is to pass your test and get a bigger bike. If you've passed
your test, you're probably limited to 33bhp anyway. If you're legal for
full-power bikes, and you're still chuntering around on a single, you need a
Gixxer thou. The more information we have about you, the better we can help
you. For instance, do you take it up the arse?

LOL! There is a very fine line between information that is useful and
relevant, and information that isn't. I think somewhere in that
sentence, the line was driven over in a large 4x4, then reversed over
just to make sure. Then possibly trampled over for the heck of it! :-D

"There is much pleasure to be gained from useless knowledge"
- Bertrand Russell, philosopher (1872-1970)

Back to the subject - thanks for all your replies. In answer to the
more serious questions - The one I've got at the moment is mainly for
passing my test (next month I hope!) and the insurance is cheap on it.
Friend mentioned it as he did it to his trial bike and suggested I do
the same. So the gist of it is that it's only really worth it with a
twin carb then?

It's only worth doing as part as a considered tuning program. Unless you
know what you're doing, you'll probably make things worse. Also, it's not
worth spending time and money trying to squeeze more go out of a learner
bike. Dick Dastardly of this parish once tuned a CG125 up to 25bhp and got
the dyno ticket to prove it, but it blew up the next week. Concentrate on
passing your test, then buy something more powerful.

Money is the real issue though - if I had enough of it I'd already
have bought my (other) friend's bandit 600 he's selling, and it would
be sitting in a garage waiting for me to pass my test. Alas!

So it goes.

Thanks again
Vicky

In some cases, yes.
But, the bigger carb may have to be modified to allow the bike to run
well.
TBH, it is a waste of time and money on most bikes to do this, it is far
easier, and far less hassle to just sell your bike and get a
bigger/faster one.
Alan.

Yes, but usually only as part of an overall tuning exercise.

(for example - more fuel/air in needs a way of getting more exhaust out,
so bigger exhaust, and you need to be able to flow the gases in and out
faster, so bigger valves, lifted open further and longer by a different
camshaft... you get the picture?)

Some bikes are under-carbed, though.

Just to add to the (mostly) useful advice already given.

There are two answers to your question :
- in theory, yes, sometimes
- in practice, no, usually.

If you're a newbie, then almost by definition this is not a sensible
thing to embark upon. There's a million and one things to learn about
riding motorcycles, and for most of them the learning will be easier
on something that is standard and moderately reliable.

Now - are there any naked photos of you on the internet?

Ooh - look mummy - Sooty and Sweep are naked.

Wow. Not often you go ginger.

Ah, I just thought it would be something to prod Champ with, and I
hadn't read the other thread.

How're you sleeping? :)

No too badly, actually. Next week is my first full week back at work
though...

Cheers
Vicky

Well, as you probably have noticed already, 'a more reliable opinion'
is not necessarily easy to find on here.

To answer your question, in general, I would say 'no'.

To get more power you generally need to burn more fuel and air mixture
in a given time (or at least more efficiently). Getting a bigger carb
on it's own generally won't work, 'cos the rest of the engine won't be
able to keep up IYSWIM.