rick 48 cub
Well-known member
Hi friends,
I have owned my 1978 cub for about 15 years. This tractor has been a huge help in mowing (59" belly), pushing snow, providing hydraulic pressure for a log splitter, moving trailers around, etc
About a week ago while mowing, my cub started a cycle of surging that became more pronounced in taller grass and going uphill. I assumed it was fuel starvation.
So today I took the zenith carb apart and cleaned every orifice with carb cleaner, copper wire, and high pressure air. I can not identify the culprit. But there are two tiny holes in the barrel/venturi. Sticking out of one of these hole felt like a sharp grain of sand. With my fingernail and compressed air, it came out. I do not know what it was.
Funny thing I had not encountered before, a tiny torsion spring that pushed the float down into the fuel bowl. This spring wraps around the axel pin that connects the float to the carb body. Apparently this spring is supposed to keep the float from bouncing when u take the tractor "four wheeling".
To my amazement, the cub started on the first try!!! I adjusted the idle air and high speed mixture screws a fraction of a turn to find the sweet spots. I took it to the back 40 with the mower deck engaged and in second gear - no surge
I have owned my 1978 cub for about 15 years. This tractor has been a huge help in mowing (59" belly), pushing snow, providing hydraulic pressure for a log splitter, moving trailers around, etc
About a week ago while mowing, my cub started a cycle of surging that became more pronounced in taller grass and going uphill. I assumed it was fuel starvation.
So today I took the zenith carb apart and cleaned every orifice with carb cleaner, copper wire, and high pressure air. I can not identify the culprit. But there are two tiny holes in the barrel/venturi. Sticking out of one of these hole felt like a sharp grain of sand. With my fingernail and compressed air, it came out. I do not know what it was.
Funny thing I had not encountered before, a tiny torsion spring that pushed the float down into the fuel bowl. This spring wraps around the axel pin that connects the float to the carb body. Apparently this spring is supposed to keep the float from bouncing when u take the tractor "four wheeling".
To my amazement, the cub started on the first try!!! I adjusted the idle air and high speed mixture screws a fraction of a turn to find the sweet spots. I took it to the back 40 with the mower deck engaged and in second gear - no surge
