Chinese carb lesson learnt.

[jamie N]

The carb on my Mercury 4hp 4T was bolloxed through the previous owner not draining the carb before the winter lay up, so I bought a Chinese copy once I'd bought the boat a year ago. The carb ran well enough, but on 3-4 occasions flooded because the needle valve didn't seal.
I blamed the fuel lines, and a bit of wax left over from 'before' causing the needle to not seal, cleaned everything and put it back together. The engine would run like a good'un, perfect colouring on the spark plug, then the same thing again....
This is annoying, and gave me doubts as to whether the problem was caused by the fuel and crud interfering with the needle, or not. Anyway, the engine was running well, so I'd not chased the fault.
A couple of days ago, it flooded again, so carb off, nothing bad seen, and put back together. It ran perfectly, but had annoyed me, so when I got home I sought out the original carb, and took the float stuff off, as well as the bowl, and today took them to the boat.
The engine failed within a boats length of leaving the pontoon, so I drifted into an empty slot, and again took the carb off and removed the bowl. Finally the light went on, and I noticed what I believe the problem to be, which is the roll pin that the float hinges on was free to slide from side to side, thus one side would come out, effectively lowering the float, causing the needle to not close the bowl. I'd liberated the 'old' roll pin from the 'old' carb, and fitted that one, which was a much tighter interference fit, and ran the engine, which runs well, and I think will continue to do so, as the fault is found and fixed.
It's easy to say that I should've noticed the loose pin, or the pin being out of position, but if you don't, you don't.

 

[Dellquay13]

The carb on my Mercury 4hp 4T was bolloxed through the previous owner not draining the carb before the winter lay up, so I bought a Chinese copy once I'd bought the boat a year ago. The carb ran well enough, but on 3-4 occasions flooded because the needle valve didn't seal.
I blamed the fuel lines, and a bit of wax left over from 'before' causing the needle to not seal, cleaned everything and put it back together. The engine would run like a good'un, perfect colouring on the spark plug, then the same thing again....
This is annoying, and gave me doubts as to whether the problem was caused by the fuel and crud interfering with the needle, or not. Anyway, the engine was running well, so I'd not chased the fault.
A couple of days ago, it flooded again, so carb off, nothing bad seen, and put back together. It ran perfectly, but had annoyed me, so when I got home I sought out the original carb, and took the float stuff off, as well as the bowl, and today took them to the boat.
The engine failed within a boats length of leaving the pontoon, so I drifted into an empty slot, and again took the carb off and removed the bowl. Finally the light went on, and I noticed what I believe the problem to be, which is the roll pin that the float hinges on was free to slide from side to side, thus one side would come out, effectively lowering the float, causing the needle to not close the bowl. I'd liberated the 'old' roll pin from the 'old' carb, and fitted that one, which was a much tighter interference fit, and ran the engine, which runs well, and I think will continue to do so, as the fault is found and fixed.
It's easy to say that I should've noticed the loose pin, or the pin being out of position, but if you don't, you don't.

I put a Chinese carb on a Honda bf2 gifted to me last year. The original carb (1997) didn’t last long before the bowl rusted out after the introduction of E10 and watery ethanol in stored fuel.
It runs but lumpy at low revs, and the choke lever needs an extra push with the lid off to fully disengage. The fuel tap has the open/close label the wrong way round on the tap cover.
Your info is another tip to file away until I get the next problem.

 

[Snowgoose-1]

The carb on my Mercury 4hp 4T was bolloxed through the previous owner not draining the carb before the winter lay up, so I bought a Chinese copy once I'd bought the boat a year ago. The carb ran well enough, but on 3-4 occasions flooded because the needle valve didn't seal.
I blamed the fuel lines, and a bit of wax left over from 'before' causing the needle to not seal, cleaned everything and put it back together. The engine would run like a good'un, perfect colouring on the spark plug, then the same thing again....
This is annoying, and gave me doubts as to whether the problem was caused by the fuel and crud interfering with the needle, or not. Anyway, the engine was running well, so I'd not chased the fault.
A couple of days ago, it flooded again, so carb off, nothing bad seen, and put back together. It ran perfectly, but had annoyed me, so when I got home I sought out the original carb, and took the float stuff off, as well as the bowl, and today took them to the boat.
The engine failed within a boats length of leaving the pontoon, so I drifted into an empty slot, and again took the carb off and removed the bowl. Finally the light went on, and I noticed what I believe the problem to be, which is the roll pin that the float hinges on was free to slide from side to side, thus one side would come out, effectively lowering the float, causing the needle to not close the bowl. I'd liberated the 'old' roll pin from the 'old' carb, and fitted that one, which was a much tighter interference fit, and ran the engine, which runs well, and I think will continue to do so, as the fault is found and fixed.
It's easy to say that I should've noticed the loose pin, or the pin being out of position, but if you don't, you don't.

Thanks for sharing.
A few years back , I had a Chinese replacement carb for a 4hp 2T Mariner.

Fortunately , it solved all of my problems first time. I also upgraded to 5hp rather than 4hp. The carb was silly money, about £55 delivered.

 

[Mark-1]

I put a Chinese carb on a Honda bf2 gifted to me last year. The original carb (1997) didn’t last long before the bowl rusted out after the introduction of E10 and watery ethanol in stored fuel.
It runs but lumpy at low revs, and the choke lever needs an extra push with the lid off to fully disengage. The fuel tap has the open/close label the wrong way round on the tap cover.
Your info is another tip to file away until I get the next problem.

The carb came with a fuel tap?