Life with a Chinese Carburetor (1 Viewer)

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Dec 18, 2012
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Cuenca, Ecuador
I agree completely. I'm an old hot rodder and if they won't start at the touch of the key, something is wrong. Anything that needed to be pumped or choked in the kind of temperatures I deal with down here, needed and got attention. So I think Pin Head and other folks are right. There is still something in the plunger circuit that is keeping this thing from working right.
 
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The accelerator pump is easy to evaluate or diagnose. Just take the air cleaner off and look at how it squirts when you pump the throttle.

A normal start at temperatures above 50F should only require a couple of pumps to start in the first two revolutions.

I think you have an idle circuit problem so it never gets enough fuel unless the choke is applied. You also seem to have a problem with fuel coming out after you shut it down which requires a hot restart / flooded carb procedure.
 
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Here is an update folks that just defies all reason. I have been combining the best parts from my '70 FJ40 into a '79 FJ40 I bought in September. I got the rig back a few weeks ago and set about incorporating the wiring harness as well as installing new fittings for heating. Once that was done it was time to hit the key and see what happens. I had given it a shot of gasoline down the carburetor throat and the engine fired right up. While the mechanic did indeed have the distributor off a tooth and the points were reading 20 dwell instead of 41, it ran smooth. And it has run smooth ever since. So how on earth the hoist lift of the motor from one rig to another can possibly impact the performance of the carburetor I cannot fathom. So the new Aisan continues to reside in the box.

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There are a couple of things I can think of.
1. You poured gas in the carb this time and not in the past. If your bowl was empty or your accel pump is not working, this problem may come back.
2. It's a pretty common problem for these chinese carbs to have aluminum chips in them that eventually clogs up orifices. It's not hard to imagine that pulling the engine and shaking the carb around would free up one of these chips that caused the original problem. If so, it may well come back. I would DEFINITELY pull the bowl drain plug and try to get as much of that junk out of there if there is any.

If it starts and runs well without putting fuel in the carb AND if you don't find aluminum chip junk in the fuel that drains from the bowl AND the fuel level indicator stays in the middle of the window, I'd declare success for now and go have a beer.
 

GA Architect

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Funny how things work out sometimes.............Why the inline fuel filter at the carb? Be sure to keep those clamps tightened up. If you don't already carry one, be sure to have a fire extinguisher handy just in case. When I bought my rig, it had a short piece of rubber hose at the carb. And after a reputable individual poked-a-funny at it, I formed and replace that line from the fuel pump to carb.

before:
img_0306-jpg.909415


after:
img_0333-jpg.912635
 

Racer65

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Jan 28, 2012
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Here is an update folks that just defies all reason. I have been combining the best parts from my '70 FJ40 into a '79 FJ40 I bought in September. I got the rig back a few weeks ago and set about incorporating the wiring harness as well as installing new fittings for heating. Once that was done it was time to hit the key and see what happens. I had given it a shot of gasoline down the carburetor throat and the engine fired right up. While the mechanic did indeed have the distributor off a tooth and the points were reading 20 dwell instead of 41, it ran smooth. And it has run smooth ever since. So how on earth the hoist lift of the motor from one rig to another can possibly impact the performance of the carburetor I cannot fathom. So the new Aisan continues to reside in the box.

What's the part # on the label of your Aisan carburetor?
 
Joined
Dec 18, 2012
Messages
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Location
Cuenca, Ecuador
Funny how things work out sometimes.............Why the inline fuel filter at the carb? Be sure to keep those clamps tightened up. If you don't already carry one, be sure to have a fire extinguisher handy just in case. When I bought my rig, it had a short piece of rubber hose at the carb. And after a reputable individual poked-a-funny at it, I formed and replace that line from the fuel pump to carb.

before:
img_0306-jpg.909415


after:
img_0333-jpg.912635
I run two of them. One before the fuel pump and one before the carburetor. Folks tell me the gasoline is not refined as well here as it is in the USA. Fortunately we aren't using any MTBE or Corn. While the old tank had been flushed repeatedly with water, I would still need a new lower filter at every 3,000 mile oil change. We'll see how that goes with the new tank. I know I sure like the increased size. The taller gear ratio is giving me 15 mpg vs the old 11 or 12 mpg, same motor and carburetor.
 
Joined
Dec 18, 2012
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There are a couple of things I can think of.
1. You poured gas in the carb this time and not in the past. If your bowl was empty or your accel pump is not working, this problem may come back.
2. It's a pretty common problem for these chinese carbs to have aluminum chips in them that eventually clogs up orifices. It's not hard to imagine that pulling the engine and shaking the carb around would free up one of these chips that caused the original problem. If so, it may well come back. I would DEFINITELY pull the bowl drain plug and try to get as much of that junk out of there if there is any.

If it starts and runs well without putting fuel in the carb AND if you don't find aluminum chip junk in the fuel that drains from the bowl AND the fuel level indicator stays in the middle of the window, I'd declare success for now and go have a beer.
When I finish with the '79 I will start working to put the '70 back into running condition. That Aisan exhibited the same starting problems and needing to flutter the gas pedal from a stop but ran fine on the main system. I will probably put the Chinese carb on that motor and save the Aisan for a future rebuild, or decoration.
 
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Mar 3, 2014
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New Mexico
This probably has nothing to do with your carb, but my 40 originally came from Quito, Equador and I was chasing carb issues for a long time. Mine would start and idle fine but when i drove it it would buck and hesitate and then die. Then it would start back up again. I had a chinese carb and a mechanic told me I needed to have the carb rebuilt for $600, so instead of rebuilding the chinese carb, I ended up shipping my original Aisan off to Jim C for a rebuild. When I got it back, same problem.

I finally traced the problem to the hard line on the fuel tank that was clogged with braze. Some one had brazed the hard line onto the flange and clogged the line in the process and there was only a pin hole of fuel getting through. It was 98% clogged. It was just enough fuel for the truck to idle but not enough for it to run the main jets.

I had to drain the tank, drop one side of the tank, remove the flange, drill it out, and replace the hard line. Once I fixed that all my problems went away and it runs perfect now. 2-3 pumps and it starts instantly even on cool mornings. Haven't had to use the choke yet.

Qiute a few things on my truck have been brazed so I don't know if it's a common practice down in South America or what. Attached is a pic of my clogged hard line.
 
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Joined
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You have probably seen stories about how they keep the old US iron running in Cuba. About the same here, even though parts are available. Folks want the cheapest, fastest repair. So now I'm thanking my lucky stars that I didn't get a fuel line like you did! Yikes!
 
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As someone else mentioned, if this pos was a problem before it will probably be a problem again. Last night coming home from dinner it starts the dying, requiring choke to start, won't idle, won't pull away smoothly. We went into the grocery store early as it is the last day of football season and I just want to sit with a cold beer and watch the fellows play. It was a miserable trip. Of course on the highway it is just fine. So I hoped I could just raise the idle, nope. So I set the Seahawks game to record and got to work. It took about an hour which included making two new base gaskets. Cranked it to fill the bowl and then it lit off. I had to adjust the idle speed, darn. That was it. Just changed the carburetor, nothing more or less. As you can see in the attached picture I have found a place for this Trollhole made in China carburetor. Once it decomposes I can spread it in the garden, that will be the only other use I have for this pos. Thanks to all for your time, help, guidance and sharing of experience. I wish you all a Happy, Healthy & Prosperous New Year. Lenny.

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