This is my first time on here, so I don't exactly know how to post so here goes.
My JD-425 has a flooding problem. Sometimes it runs ok, and sometimes not. When I turn on the ignition, the fuel pump starts (as normal) and I can usually start it. Then, after running for a while, it begins flooding. This is between 15 minutes and half an hour most of the time. I can keep it running if I go full throttle and have the tractor under load, like mowing grass, but there is so much gas entering the carb that there is a bit of black smoke as well.
If I stop it and remove the air cleaner, and look into the carb, there is gas everywhere.
Here is what I did so far...
The carb was new 3 years ago. But I removed it, and took it apart (did this 3 times). Each time I took it apart and put it back together, I know I did it right because the machine started and ran as noted above. I thought it just might be plugged or something. The first time I took it apart I also replaced the electric solenoid valve, just to be sure. And I know it works, because I saw it operating with the carb disassembled. Then, I thought it might be that the float valve was leaking or perhaps the floats had a hole and was full of gas. All was good. When the carb was back together, I blew into the fuel hose when the carb was full of gas and proved that the float valve was working. Hmmm. There is a manual in-line fuel shutoff valve, so what I did was throttle it back so that it would take 30 seconds to to let about an ounce of fuel out. Full blast, the pump actually pumps a lot of fuel. This time, I was able to keep the machine from flooding too bad. And was able to mow the 1 acre of grass I have. Today, however was different. It ran for about 5 minutes, then began to act up. I turned it off, removed the air cleaner and looked into the carb. When I turn the ignition switch on, (not engaging the starter) I can see tons of gas coming out of every carb orifice, flooding into the engine, gas everywhere! This is without the engine running! The only thing I can come up with is that the fuel pump for some unknown reason has too much pressure behind it and is causing the float valve to not shut.
Another wierd thing is that when I turn a sharp corner, under the flooding condition, the flooding gets noticably worse.
Any ideas anyone? Is there a pressure regulator somewhere in the fuel pump line?