Real 20mm Carburetors vs fakes - with pictures

[humanshield]

Apr 4, 2015 13:45:12 GMT -5 walleye1963 said:

Hi guys thought I'd let youno I sent for a 20mm carb from 02starrider on eBay it look 3 days to get it.used my new Digital caliper to measure it and it read 20mm.I've got stuff from him before and will again.

Did you take the butterfly out and measure that.....or just inside the engine side of the throat?

[walleye1963]

I put the caliper in as far as it would go.it measured20.69.it went almost all the way to the butterfly so I'd say it was 20mm.

[walleye1963]

Should I take the butterfly out and measure it?

[humanshield]

Apr 4, 2015 15:57:01 GMT -5 walleye1963 said:

Should I take the butterfly out and measure it?

That is the only way to be certain

I've seen them machined ALL the way right up to the butterfry.....and still have an 18mm butterfly valve

If you do, let me know because I will immediately order one from them too

[walleye1963]

I tryed to get the scews out but man I can't get them to bug.I did take the bowl off and it was hard to see but it looks like a 85 main jet its getting dark I'll try to get a pic tomarow of the intake.

[walleye1963]

Mar 23, 2015 7:52:24 GMT -5 humanshield said:

I touched on this once before in another thread but due to a very large number of people buying fake 20mm carburetors, I wanted to make a thread dedicated to this.  I got burned myself and this might save others from getting duped.

There are a LOT of vendors selling 18mm carburetors as "20mm" carburetors.  Especially on ebay.

What they are doing it taking an 18mm carburetor (dirt cheap from china in bulk), and machining a very small portion of the outlet flange on the intake manifold side so that the last 1/2 inch or so is 20mm, but NOT the entire venturi going through the carburetor and the BUTTERFLY size is still 18mm.

Doing this does NOT increase the performance of the carburetor and does not increase the volume of air that can pass through the carburetor.   You will still have an 18mm carburetor.  Imo, it's downright false advertising.

Here are some photos to help identify fake 20mm carburetors....

In this first photo you can see the ridge left from the machining where it stops.
As you can see, after the machining, the bore size is larger ONLY up to the machining ridge.
All they did is bore a hole into the barrel that is 2mm larger than the original 18mm.
But because the machining stops before the butterfly valve and because the rest of the venturi
is still 18mm, there is no performance gain.  You still have an 18mm carburetor.



Here is an angular view of another fake 20mm carburetor.
Again you can see where the machining stops.
To try and conceal the machining, some carbs are machined all the way right up to the butterfly valve
making it a bit harder to tell it was simply machined.  You need to verify that the carb in fact has a 20mm
butterfly before purchase.



Finally, here is a photo of a TRUE 20mm carburetor....
There is no machining and the seller will verify that the butterfly valve is in fact 20mm.
(The butterfly valve is the brass plate with two screws)
This carburetor can provide improved air flow volume for Big Bore Kit motors.

I took a closer look at it.and in your nomber2 pic.this carb do's have a lip on it so I can't say for sure if it's18 or 20mm carb.I tryed to get the butterfly off .got one scew off but the outher .one started to strip out .so I don't no owell I guess I can look at it this way I eather got a 20mm carb or I paved $35 for a unseld 18mm carb

[dude]

I've tried to find out how to measure a CVK carb. Nothing set in stone. At one time I had a slide style carb bored a 1 1/2 mm. Just something to think about is the stiffness of the CVT spring. Like a holley carb vacuum secondary springs. (Color coded)

[walleye1963]

Here's a pic of the carb with the lip .got carb yesterday from 02 star rider .inside intake says its 20mm but with the lip I don't no what do you guys think?

[stevec]

i always try to buy name brand carbs like authentic keihin, mikuni, hoca, NCY, oko and so on, buying a replica or a cheap carb is never a good idea, you end up with problems.
02starider, gy6racingteam and scooter elements usually have the better parts on ebay.

[humanshield]

Apr 4, 2015 13:45:12 GMT -5 walleye1963 said:

Hi guys thought I'd let youno I sent for a 20mm carb from 02starrider on eBay it look 3 days to get it.used my new Digital caliper to measure it and it read 20mm.I've got stuff from him before and will again.

All the fake 20mm carbs read 20mm if you measure inside the throat part of the carb where it goes to the intake manifold.

Only was to be sure is if it has a 20mm brass butterfly valve.  That one thing tells you the VENTURI is 20mm.  And that's what counts.

I don't know if China is duping wholesale buyers in the US or if wholesale buyers in the US are duping consumers.

[Lucass2T]

Apr 5, 2015 18:36:34 GMT -5 stevec said:

i always try to buy name brand carbs like authentic keihin, mikuni, hoca, NCY, oko and so on, buying a replica or a cheap carb is never a good idea, you end up with problems.
02starider, gy6racingteam and scooter elements usually have the better parts on ebay.

Nameless carbs are replica's of replica's, those are the worst.
There are only seven real motorcycle/scooter carb brands. The first three are the most common:
- Dellorto
- Mikuni
- Keihin

- Amal
- Arreche
- Bing
- Lectron

Everything else are all replica's.

[iwannascoot]

I have a Keihin that I'm pretty sure is a clone. The casting and finish are worse than my Taotao stock carb. How would you know if your part in genuine? Patent laws don't seem to matter much these days.

Billy

[humanshield]

China in particular has obliterated patent laws globally. They are duplicating anything and everything including the VW beetle and Ford F150 among tons more.
And as the US weakens and China grows stronger, this will get MUCH worse.
Unlike the USA, they have their own self interests at the very front.

If it's any consolation, Chinese products are slowly improving in quality.  That includes their stealth jet fighters and other military weapons.

So how can you be sure? I'm not sure you can always. A sure sign is if it does not have one of the names listed in the post above.

I bought a few TimKen bearings for my truck recently and I had to go through a bunch of documents and verification procedures to verify if they were genuine or not.  I even had to WEIGH them.  Crazy.

[stevec]

Apr 8, 2015 7:29:28 GMT -5 Lucass2T said:

Apr 5, 2015 18:36:34 GMT -5 stevec said:

i always try to buy name brand carbs like authentic keihin, mikuni, hoca, NCY, oko and so on, buying a replica or a cheap carb is never a good idea, you end up with problems.
02starider, gy6racingteam and scooter elements usually have the better parts on ebay.

Nameless carbs are replica's of replica's, those are the worst.
There are only seven real motorcycle/scooter carb brands. The first three are the most common:
- Dellorto
- Mikuni
- Keihin

- Amal
- Arreche
- Bing
- Lectron

Everything else are all replica's.

you didn't mention Naraku or HOCA, those are also authentic.

[Lucass2T]

Apr 8, 2015 9:45:11 GMT -5 stevec said:

Apr 8, 2015 7:29:28 GMT -5 Lucass2T said:

Nameless carbs are replica's of replica's, those are the worst.
There are only seven real motorcycle/scooter carb brands. The first three are the most common:
- Dellorto
- Mikuni
- Keihin

- Amal
- Arreche
- Bing
- Lectron

Everything else are all replica's.

you didn't mention Naraku or HOCA, those are also authentic.

Not really. Those PWK carbs HOCA has are just a copy of the keihin pwk seen on 85cc dirtbikes. I don't know about the 4stroke carbs but the two stroke stuff are just a chinese made copy of the Keihin PWK.