Chinese carburetors

[JDIH]

I know the topic of Chinese carburetors has been discussed before but I can't find the info I'm looking for. I have a Farmall C that I bought with a Chinese carb (Reedmoral brand) already on it and he no longer had the original. Question 1) Is there a trick to adjusting these? There's an extra adjustment screw that the original doesn't have. I can get it to run perfect and then it sits overnight and back to running like garbage, always having to run with the choke on some at different rpm ranges, until you fool with the adjustments again for a while. Something has to be changing in to make it run bad but I can't figure out what. Question 2) is there a Chinese brand that's better or worse than others? I know people on here have used them with success before. I can get a used factory carb for 4x the price of an aftermarket and it will need rebuilt. I'd rather not spend the extra money if I don't need to but I will if that's what I have to do so it will run right.

 

[Janicholson]

Most adjustment variability is particles of material/rust plugging jets or passages. There is some chance that a float rubbing on the bowl could be causing changes in luel level, but more rare. I would take a fuel flow check from the drain and expect a pint in 2 minutes. If good, I would take it apart and clean it. Jim

 

[John in Ct]

I don't know much but having to run with the choke ok is usually a symptom of not getting enough fuel.

 

[Fritz Maurer]

I have no particular love or hate of Chinese carbs, but many times the installer is at fault. A lot of times, the tech doesn't make any effort to sanitize the rest of the fuel system, just turn the gas on and hope for the best. This initial rush of gasoline filling washes loose crud into the carburetor.

The sequence of events you are describing sounds like water in the gas... runs good, then the water separates overnight and runs bad the next morning until a more burnable mixture of gas/water is in the bowl.

 

[JDIH]

Thanks for the advice everybody. Some junk floating around in there makes sense. I'll pull it apart again and make sure it's clean. I'm confident it's not water in the fuel as I've ran a couple tanks through it

 

[300guy]

If he bought this off Amazon then I would throw it as far as you can!!!!! I have seen 3 of these carburetors and everyone was a piece of junk and ran just like you described straight out of the box!! A guy worked and worked on for he didn't know how many hours and finally when and bought an original one. I think they have metal stuff left inside the casting from who knows where. Anyway that's the way they acted. Run good for a while an then start running terrible just like a passage becomes plugged. The one the guy worked on ran wires through passages numerous times, sprayed cleaner through them and nothing ever helped. It liked to drive him nuts!!!!!

 

[used red MN]

You might check your distributor mechanical advance to see if it is sticking. With the rotor between your thumb and forefinger it should twist clockwise just a bit against spring pressure and then when released turn back.

 

[grandpa Love]

Always, always blame the carburetor! Do you have a good screen in your sediment bowl? Bowl catches water and debris. I'm betting you are getting trash in the carb, there is no way an inanimate object ( like a carb) adjusts itself over night . If the "Chinese" carb works great sometimes, then it ain't the carb.

 

[Brownie450]

Our super C came with a Zenith carb & is very finicky
on float level. Jim is possibly right with the float dragging
on the bowl. Possible that the float pin isn't square with
the world.
Worked with brothers 656 last summer for carb trouble.
Float hinge pin/ float wasn't right & caused lots of
problems.
Jim

 

[DanielW]

The Chinese carbs I've worked on with were either for Ford N's or a replacement M/S for an old Massey. Only one worked moderately ok. The problems I encountered in those ones were:

a) The main adjustment needle on some of them was machined on way, waaay to blunt of an angle compared to the OEM. It just didn't meter fuel as it should, and it was very tricky to try and dial in. Due to the blunt angle, 1/4 turn on one of those blunt Chinese main jets is equivalent to about 2 turns on the OEM carb adjustment.

b) Not sure if this applies to other Chinese carbs, but on the ones for the N's there's a port in the bowl that's not drilled out properly. There's lots of documentation on these forums about how and where to drill it out if you have one of the aftermarket carbs.

c) The main jet orifice diameters on the aftermarket carbs tends to be significantly oversize on the ones for the N's. As with above, there's lots of documentation on these forums about how to fix (usually getting a brass set-screw with the appropriate metric thread, drilling it out, and using it as the main jet orifice).

d) On one of the aftermarket carbs that worked reasonably well for me (one of the more expensive ones, not the uber-cheap $70 ones) it started to run rough after an hour or so of use. Took it apart, and found the fasteners were loose and there was some machining swarf inside. Cleaned it up, tightened everything up properly, and it ran ok after that.

I have no specific hatred of Chinese carbs - its amazing what they can provide for so cheap. But it seems to be very hit or miss with what you get. Far better to just keep and rebuild the original. Brownie's point of the float rubbing the bowl is definitely something to check. Not sure what tractor(s) you're dealing with, but the float/carb used on our Super W6 just barely fits in the bowl - if it's bent a tiny bit either way it will rub and cause erratic running.

Also, make sure you do a drain test to make sure you have free flow coming from your tank. With the age of the tractors discussed on these forums, having the tank flow partially restricted with rust/gunk in the tank is a very common problem that's talked about quite frequently on here.

 

[560Dennis]

Was plowing with the Farmall C Saturday. Stalled ,thunder. Looked in the sediment bowl ,had rust small amount in the bottom barle visible from the outside. . That’s enough of this ,going to get a sealer kit somewhere.
I fought this issue with the other SC .
what issues I’ve had.

 

[timcasbolt]

If he bought this off Amazon then I would throw it as far as you can!!!!! I have seen 3 of these carburetors and everyone was a piece of junk and ran just like you described straight out of the box!! A guy worked and worked on for he didn't know how many hours and finally when and bought an original one. I think they have metal stuff left inside the casting from who knows where. Anyway that's the way they acted. Run good for a while an then start running terrible just like a passage becomes plugged. The one the guy worked on ran wires through passages numerous times, sprayed cleaner through them and nothing ever helped. It liked to drive him nuts!!!!!

And I have seen 4 of them that made that 50 year old engine run like new.

 

[BarnyardEngineering]

As far as one being "better" than any other, no. They're all made on the same assembly line in the same factory. Only difference is (sometimes) packaging, and price.

 

[JDIH]

Always, always blame the carburetor! Do you have a good screen in your sediment bowl? Bowl catches water and debris. I'm betting you are getting trash in the carb, there is no way an inanimate object ( like a carb) adjusts itself over night . If the "Chinese" carb works great sometimes, then it ain't the carb.

It is definitely something with the carb, otherwise half choking it wouldn't straighten it out. I'm aware of how a sediment bowl functions. It is new and also the fuel line is new.. I'm also very aware the carb can not adjust itself over night. As other posters said it's probably some kind of debris in the carb, so I will disassemble it again to inspect and thoroughly clean