Not the same as the other reply

On Sat, 14 May 2016 00:13:16 -0400, wrote:
On Sat, 14 May 2016 00:04:42 -0400, Micky
wrote:

On Fri, 13 May 2016 22:58:57 -0400, wrote:

On Fri, 13 May 2016 22:04:18 -0400, Micky
wrote:

On Fri, 13 May 2016 16:09:39 -0700 (PDT), wrote:

On Friday, May 13, 2016 at 5:41:56 PM UTC-5, Micky wrote:
Spring is here and it's time to work on the scooter I think I posted
about last fall. This is a TaoTao 49/50cc scooer made in the
People's Republic of China.

The carburetor needs a cleaning, or I can buy a new one. Matching
ones range from $18 to a little over $50. URLs available if wanted.
Do you think there is a positive correlation between price and
quality? A negative one? Any one? Or are they all really the
same thing? I once saw a particular model of camera for sale online
for between 50 and 200 dollars, very same thing.

Generally when you arer talking parts for Chinese equipment - or
buying from chinese sources or importers, you are buying the same
stuff at different prices depending on the business model of the
seller. Some buy in huge volumes at low cost and sell at low margines.

I can buy an item from one of those sellers for $0.18 US including
shipping from Hong Kong.

I can buy the exact same part from an importer in Texas or California
for $7 plus $18 shipping and handling.. The EXACT same part.
Absolutely no difference in quality except POSSIBLY the importer has
inspected the item to ascertain it is what the manufacturer in China
said it is, and that it is all there and fully assembled. In an
extreme case it may even have been tested to determine it is in
functional condition.

So I buy 3 for $0.56. If one is no good I still have another spare - -

That's pretty much what I thought. I think even the ones with only 1
or 2 photos fit the same as the one with 8 photos.

Almost by accident I learned another factor. There's a scooter
webforum that I'd forgotten about. But I went there and searched on
carbur and read a couple posts. One said "I have a Keihin clone 18mm.
I just upgraded to a 20mm. This shoud fit if you have a 139QMB 50cc
engine." And I thought, Huh. I thought my intake was 40mm and
output was 28.

So I asked, and they are talking about the carburetor throat, and I
was referred to a thread from 13 months ago. It seems even in this
cheap market, there are both 18 and 20mm carbs, though maybe the 20mm
are not so cheap. (Where 18 and 20 are the inside diameter and 28 is
the outside diam, around which the intake manifold is attached.)

Because they were talking about a lot of fake 20's, where they take an
18 and mill it 2mm bigger, but only at the exit, the last inch or so,
but the butterfly is still 18, so it doesn't improve performance at
all.

So I went back and looked at 5 of the 6 models I listed earlier, and
three say they are 18 (two in their title and one in a measurement
shown in red in a picture) and two don't say. None claim to be 20. Of
the two that don't say, one says it's a model PD18J and the second is
a PD18. The 18 might mean 18mm, or not, and the J-suffix probably
means some little difference there.

The one I wanted with the most pictures says it's 18, and based on the
picture, it has not been milled bigger. Another one has a plastic
protective cap on the hole so you can't see, another one has so much
reflection it's hard to tell, and the PD18 and 18J actually do look
like they were milled bigger, but since they don't claim to be 20, so
what. Maybe they used to claim that and got rebuked. One or 2
posters in the forum said they had complained to Ebay and Ebay
refunded his money and shipping charge and didn't make him ship back
the modified one. Maybe they punished the vendor....

That might account for these two models but I googled
GY6 carburetor 20mm and there are about 6 of them, two on
Amazon. Some prices in the $30's. I don't know why I didn't come
across any of them before. The very first one didn't look like it
was milled, but if they're cheats, they could be using an unmodified
picture. (The thread listed some good vendors and bad, but I can't
remember things like that. It doesn't matter, I'm not actually buying
one.)

I've only been looking for fun, I'm sticking with 18, but this post is
interesting "50s use a 18mm why a 20?? it is not going to do anything
more than an 18mm jetted right. You people think slapping a bigger
carb is going to give you something but unless you build the motor up
quite a bit a bigger carb is not needed and will not give you anything
but waste gas on you and make it harder to tune to get the motor to
run right at all throttle positions. Alleyoop Read mo
http://itistheride.boards.net/thread/4391#ixzz48c7q8Kzr "
I suspect he's right.

Another guy claimed you could turn an 18 into a 20 with a Dremel
tool!!!!

Another guy mentions 2 stroke motors, so i was wrong about that.
Sorry.

Hmm. Those 20mm seem to come with
"40mm Air Box Manifold. 20mm Intake Manifold."

But another carb in my original list said 38 input and I think that's
what I have (not 40). And for the output, one in my original list
said 18, but on mine it was hard to measure, hard to see. I guess I
will take it apart before I buy the carb. In fact they wouldn't put
the measurements in bright red if they were all the same.