Thanks to both of you. I'm beginning to suspect my deck is different. There don't seem to be any handles on it at all. What the book tells you to do is: "Put a 15mm closed wrench or a socket on the idler sheave nut (A) and rotate clockwise to move idler sheave toward front of tractor and hold to release belt tension." I tried that, but it doesn't give nearly enough tension release. I'm begining to wonder... I bought the new belt from Alexander & Duncan in Leominster UK, and while I was at it I bought a second one as a spare. The second one has "John Deere" on its outside face, but the first doesn't, and it's the first one that I mounted. Both these belts came in an identical thin card sleeve, but they weren't coiled quite the same way. I'm wondering if someone "made a mistake" and put a non-original belt in a John Deere sleeve. But be that as it may, is it possible that your 48" deck and mine aren't the same? I bought the whole thing less than a year ago, so maybe they changed the pattern. Passthegravey: does your manual talk about slipping a wrench over the left-hand idler sheave nut?

I had the exact same issue...replaced fuel pump, spark plug, cleaned fuel lines and replaced fuel still no start. Turns out the intake valve push rod (aluminum) was bent... replaced it and re-gapped the valve rocker arms and the engine started immediately! Anyone know why B&S used aluminum valve push rod? Answer: IT ALWAYS BENDS! Very poor design I think. I've never seen that in a car or ANY other mower I've owned in the last 50 years.

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. 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? Thanks.

Well, first cut has taken place. The mulch kit was dealer fitted but looks different from the photos above, as there is no block on the side discharge (should I check this out with the dealer?). Having only used a 16inch push gas mower, it's quite a big change to use a fancy smancy tractor. It took several passes before I figured out the blades weren't on! It's also shown up the big dips I have on my lawn and the two holes! I must fill those up and toss in some grass seed. The plug in hose thingy worked great. I'm just thinking about smoothing out some of those tight bends in the plastic border that separates the gravel from the grass. I will have to reset some portions. Can anyone tell me what I should be aiming at when setting the plastic border height? Are all plastic borders the same? Thanks.