I bought a 314 that's in pretty good shape a few months ago. I've been going through it fixing little things like bushings in the steering system and various other things. I'm really enjoying the learning experience. After I bought it, I noticed a rattling sound after it warmed up. Figuring it's probably due for an engine rebuild, I was planning to work with my friend who has a repair shop this winter.
As I dug into the sound last week, I found the what I thought was an engine rattle, is actually air and fuel blowing out of the carb. It gets progressively worse as I get to full throttle. It doesn't sputter when at idle.
My question is what causes this? Could it be a carb problem like the float valve seating? Maybe an internal valve leaking and the air is escaping through the carb? I can feel a significant amount of air blowing out of the vent tube below the carb. I'm not very knowledgeable about the inner working of an engine. So if this doesn't make sense whatsoever, just ignore it........lol.
The engine runs really good. It isn't missing or anything. It's just sputtering out of the carb. I will say the high and low speed mixture needles are set on the rich side compared to what the service manual suggests (both about one full turn past recommended settings)
I ordered a carb rebuild kit since they are so cheap. I'm curious what your thoughts are. I absolutely love this tractor. I'm going to do whatever it takes to get it right.
Here is a short video of what it's doing.