Author Topic: Cheap carb jets, warning  (Read 580 times)

Offline Canuck750

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Cheap carb jets, warning
« on: September 22, 2021, 01:54:48 PM »
The Guzzi content is being cheap,

I bought two pairs of Mikuni pilot jets off Ebay, made in good old China. Now I know that all reputable web sites recommend using the real Mikuni jets but being a cheapskate I thought I would give the China copies a try.

A TOTAL waste of money

using a micro set of drill bits I measured with a micrometer the results are just silly -

One 27.5 measured appx 36 and the other appx 34

One 32.5 measured 30 and the other appx 29

The 30 jets I had originally in the carbs (no idea if they are Mikuni jets) would not pass a 30 drill bit through, closer to 28~29, drilled them out to a 30

The Chinese made Mikuni jets are absolute junk, save your money and buy the genuine parts!!!
48 Guzzi Airone, 57 Guzzi Cardellino, 65 Benelli Barracuda, 66 Aermacchi Sprint, 68 Gilera 106SS, 72 Eldorado, 72 Benelli 180, 74 Guzzi 750S, 73 Laverda SF1, 74  Benelli 650S, 75 Ducati 860GT, 75 Moto Morini 3-1/2, 78 Moto Morinii 500

Offline bacongrease

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Re: Cheap carb jets, warning
« Reply #1 on: September 22, 2021, 09:25:17 PM »

    Are we surprised?


    :embarrassed:

 :popcorn:

 :undecided:

Offline nc43bsa

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Re: Cheap carb jets, warning
« Reply #2 on: September 22, 2021, 10:53:26 PM »
    Are we surprised?


    :embarrassed:

 :popcorn:

 :undecided:

We are not.   :grin:
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Online Scout63

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Re: Cheap carb jets, warning
« Reply #3 on: September 22, 2021, 11:01:33 PM »
Thanks for the tip.  Talk about a tuning nightmare. Itís hard enough to tune carbs with accurate jet sizes.
Ben Zehnder
Orleans, MA USA
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Re: Cheap carb jets, warning
« Reply #3 on: September 22, 2021, 11:01:33 PM »

Offline SIR REAL ED

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Re: Cheap carb jets, warning
« Reply #4 on: September 23, 2021, 06:27:15 AM »
The Guzzi content is being cheap,

I bought two pairs of Mikuni pilot jets off Ebay, made in good old China. Now I know that all reputable web sites recommend using the real Mikuni jets but being a cheapskate I thought I would give the China copies a try.

A TOTAL waste of money

using a micro set of drill bits I measured with a micrometer the results are just silly -

One 27.5 measured appx 36 and the other appx 34

One 32.5 measured 30 and the other appx 29

The 30 jets I had originally in the carbs (no idea if they are Mikuni jets) would not pass a 30 drill bit through, closer to 28~29, drilled them out to a 30

The Chinese made Mikuni jets are absolute junk, save your money and buy the genuine parts!!!

You get bonus points from me, for being true to our ideology rather than exercising good sense.

We all get tempted to go to the dark side from time to time, which is why WG is such a great source of information and experience.

It's kinda like you are a PhD working on a Cold Fusion reactor.....
"There's two kinds of people in the world; those for whom no explanation is necessary, and those for whom no explanation is possible."

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Offline Petrus Rocks

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Re: Cheap carb jets, warning
« Reply #5 on: September 23, 2021, 07:08:28 AM »
Had a similar experience.  Tuning my CZ400 with Mikuni installed.  Bought a range of main jets from #200 to #300.  Put the correct main in for the moddedCZ- ran awful ??  very rich.  Hmmm-looked through my other jets, found the same size, worked great!
Looked at the problem jet- the #270 was the same size as the #300 and same as the #200!  Every jet looked like it had been drilled out to a #450.  Buying real Mikuni from now on...

Offline huub

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Re: Cheap carb jets, warning
« Reply #6 on: September 23, 2021, 10:33:42 AM »
i had pretty poor, and pretty good experiences with chinese jets.
the pilot jets i bought were not drilled accurate, the main jets were fine
 if you decide to use them , measuring them before use is a good idea.

if you dont want to, just buy the genuine mikuni.

Offline kballowe

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Re: Cheap carb jets, warning
« Reply #7 on: September 23, 2021, 10:57:20 AM »
At work, we have a real problem with counterfeit parts - even from some of the more reputable suppliers.

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Offline Canuck750

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Re: Cheap carb jets, warning
« Reply #8 on: September 24, 2021, 05:42:15 PM »
At work, we have a real problem with counterfeit parts - even from some of the more reputable suppliers.

I don't think I would trust any Chinese part that is installed in a stress condition, such as 'high strength' nuts and bolts or bearings, I heard from a local bearing shop that the Chinese bearings can be of such poor quality that they don't even like to sell them but some folks only look at the cost (something I am trying to change in my own thinking)
48 Guzzi Airone, 57 Guzzi Cardellino, 65 Benelli Barracuda, 66 Aermacchi Sprint, 68 Gilera 106SS, 72 Eldorado, 72 Benelli 180, 74 Guzzi 750S, 73 Laverda SF1, 74  Benelli 650S, 75 Ducati 860GT, 75 Moto Morini 3-1/2, 78 Moto Morinii 500

Offline 80CX100

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Re: Cheap carb jets, warning
« Reply #9 on: September 24, 2021, 06:40:56 PM »
I don't think I would trust any Chinese part that is installed in a stress condition, such as 'high strength' nuts and bolts or bearings, I heard from a local bearing shop that the Chinese bearings can be of such poor quality that they don't even like to sell them but some folks only look at the cost (something I am trying to change in my own thinking)

     Yup, the last time I replaced the bearings on my trailer, regrettably I did the job on the weekend and was forced to buy the only bearings available at my local auto parts store. The new Chinese bearing sets weighed about a 1/3 of the originals, obviously much lower quality steel/material.

      You even have to be careful with well respected and trusted name brands. I can't remember the name of the country of manufacture on the box, but the last set of SKF fork seals that I bought on Amazon were  made off shore.

       Modern parts can be a coin toss, if you're lucky you can read the packaging for the place of manufacture before purchasing.

      fwiw
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Offline Kiwi_Roy

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Re: Cheap carb jets, warning
« Reply #10 on: September 25, 2021, 02:00:13 AM »
Before taking my Griso to the arctic circle I thought I would treat it to new wheel bearings, what was available All-Balls from China.
At some stage of the trip one bearing locked up snd started spinning on the shaft.
DSCN0422" border="0
I should have known better, the Chinese don't allow Chinese bearings in their motors and pumps that we supplied them for our plants over there.
They do know how to make good stuff but if they can take a short-cut they will, the Chinese stator in my V7III only lasted a few months until it burned a couple of coils.
I know of a 1400 that the alternator quit on as well, Peter?
« Last Edit: September 25, 2021, 02:07:07 AM by Kiwi_Roy »
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Online pete mcgee

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Re: Cheap carb jets, warning
« Reply #11 on: September 25, 2021, 03:39:59 AM »
Chinese and quality, two words never used in the same sentence.
Go onto youtube and search for Tofu Dreg,  many vids will pop up, watch and cringe.
Remember it was western CEOs that led to this, stuff the blue collar workers and manufacturing industrues, send it all to china so they could pocket  massive bonuses.
Pete (no not the Bungendore one)


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Offline huub

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Re: Cheap carb jets, warning
« Reply #12 on: September 25, 2021, 04:43:14 AM »
chinese will make whatever you want,
if you want a 1 dollar crappy bearing , they will happily sell those
if you are prepared to pay 10 dollar for a quality item, they can do that too.
the biggest problem is knowing what you get.
At work i work a lot with chinese suppliers,  the quality we get from them is a lot better than the german and spanish suppiers we also use for the same parts.





Offline guzziart

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Re: Cheap carb jets, warning
« Reply #13 on: September 25, 2021, 07:32:04 AM »
Well, I suppose where there are loose/poor specifications, broad tolerances, tolerance stacking, mediocre quality control will cause the end user some headaches.

Anyway, I'm glad this thread was started.  I've had issues in getting an old cb125s running "good".  I've messed with carb rebuilding, carb replacement but never thought to actually measure the main jet replacements that I was buying.  In the past with my Guzzi's I've bought Dellorto parts from Herdan in Pa. and have had acceptable results.  However, for the 125 I've been going the fleabay route and chasing my tail.  Upon reading this thread, when I go back to focusing on the 125 I'll measure jet size and compare to stamped size.

Art

Offline MattP

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Re: Cheap carb jets, warning
« Reply #14 on: September 27, 2021, 01:55:40 PM »
solder up the jet and re drill it . I think I would start small because it might be hard to drill the hole smaller if to large.

Offline guzziart

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Re: Cheap carb jets, warning
« Reply #15 on: September 27, 2021, 07:57:15 PM »
solder up the jet and re drill it . I think I would start small because it might be hard to drill the hole smaller if to large.

LOL...my drilling skills are on par with my rattle can skills.  I might be tempted though if I had a good set of small drill bits and maybe a small lathe or drill press otherwise it would be a waste of time for me.

Online Rough Edge racing

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Re: Cheap carb jets, warning
« Reply #16 on: September 27, 2021, 09:07:32 PM »
 Niche Cycles in Florida has an online store and sells real brand name carbs and parts. Jets come in factory bags with the company logo for Mkuni Amal and Keihin.They have reasonable prices and really fast shipping for reasonable cost... Don't settle for generic crap or hand drilled jets when a .0005 of an  inch  can make a noticeable difference in some jetting applications...
 and there's more to jets than the hole size, the chamfer and or the length of the hole affect flow...
« Last Edit: September 27, 2021, 09:11:53 PM by Rough Edge racing »
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Offline Moto Vita

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Re: Cheap carb jets, warning
« Reply #17 on: September 27, 2021, 09:37:29 PM »
 STOP THE PRESSES! ALERT THE MEDIA! I wonder if anybody knows about cheap, inferior, merchandise?

Online centauro

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Re: Cheap carb jets, warning
« Reply #18 on: September 28, 2021, 03:49:06 PM »
Pretty much the same situation with knock-off Chinese Honda carb rebuild kits. In the SOHC forum, the usual recommendation is to stay away from non OEM Honda jets, and just use the o-rings in the kits.
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