banditt007
ArboristSite Operative
Ok so I have one of these carbs, its a chinese knock off of a walbro i believe.
The engine in question passes vac/pressure tests, and i know the problem is the carb itself. The problem is, that the carb runs very rich to the point of stalling or being very close to stalling, lowering the idle, when it is tipped on its side. Its as if the low speed needle is being richened a lot when it is tipped to the side. I have tested the primer bulb function and you can pump the bulb, and watch the psi increase on the gauge, and hold pressure each increment. Also I have tested to 8psi or so on the inlet side, and there is no leak down. I tried reducing the metering lever height (i was chicken and didn't bend it down much) and didn't really see a change in performance. Maybe i should try further but i haven't tried yet. The carb adjusts and tunes just perfect at high rpm.
I can adjust the low speed needle so lean, that it bogs on acceleration, yet when its tipped on its side (either side) or turned upside down, it runs super rich. All fuel lines test good as well as the fuel filter, no cracks in them ext. Also i noticed that its very easy when starting cold, using the choke, to bypass the point where the engine sputters, pops ext, and goes straight to being flooded. Not sure if there are other means of testing the carb than what i have described above.
As a note this is the first time i've had any trouble with these knock off carbs. For the cost sure i could just buy another one but i would like to learn about carbs and what makes them tick. Thanks in advance for any help
The engine in question passes vac/pressure tests, and i know the problem is the carb itself. The problem is, that the carb runs very rich to the point of stalling or being very close to stalling, lowering the idle, when it is tipped on its side. Its as if the low speed needle is being richened a lot when it is tipped to the side. I have tested the primer bulb function and you can pump the bulb, and watch the psi increase on the gauge, and hold pressure each increment. Also I have tested to 8psi or so on the inlet side, and there is no leak down. I tried reducing the metering lever height (i was chicken and didn't bend it down much) and didn't really see a change in performance. Maybe i should try further but i haven't tried yet. The carb adjusts and tunes just perfect at high rpm.
I can adjust the low speed needle so lean, that it bogs on acceleration, yet when its tipped on its side (either side) or turned upside down, it runs super rich. All fuel lines test good as well as the fuel filter, no cracks in them ext. Also i noticed that its very easy when starting cold, using the choke, to bypass the point where the engine sputters, pops ext, and goes straight to being flooded. Not sure if there are other means of testing the carb than what i have described above.
As a note this is the first time i've had any trouble with these knock off carbs. For the cost sure i could just buy another one but i would like to learn about carbs and what makes them tick. Thanks in advance for any help