bx2200, so different machine and some of the old timers here may say I know nothing, which I don't, but here goes.
A couple of months ago, my engine would slow and die when I put a load on it (like even going up a small hill). It would start again in a couple on minutes. Then, after a few times, it would start and blow white smoke. Long story short- I changed both fuel filters. When I took the one after the fuel tank and before the fuel pump off, white stuff came out, which eventually turned to just water. Ours doesn't sit all winter under a tarp like yours did, so we must have laid our hands on some bad fuel at one of the two places we buy. Anyway, drained all the water out, then when fuel was coming out, clamped the line (mine's rubber hose), and put on both new filters. Had to purge the injectors (on mine, just loosened the front one a bit and turned the fuel pump on until fuel was squirting out. Started and ran, but then started missing again. I went and got some biocide because someone here smarter than me told me I had mold or fungus in my tank (I don't remember which and don't care too much. lol). Added the biocide and let the thing just fast idle for a half hour or so. Hopped on, kicked it in the ass, and haven't had a problem since. The other issue I had is that on my 2200, there's a connecting rod from the foot control, back to the hst behind the right rear tire (why do you have tyres, boots, torches, and WC's?). The distal end has a ball joint on it and the end that connects to the foot control just has a right angle bend with a hole for a cotter pin. My distal end was broken, so no matter how hard I pushed on the pedal, nothing happened. I've also had a stick get jammed in the foot control, which rendered it immoveable, which made it kind of hard to do anything except go in one direction.
So, if your tractor is anything like mine, I'd look the same places- it sounds like your issues are very similar to what happened here.
I also had an issue with an oil seal on the left rear axle getting popped out. I saw fluid draining out as she was digging out multi-flora roses (I hope you don't have those damn things over there!!). I told her to take it up to the house and park it. We ran it maybe 10 minutes that way. Then, I took the wheel off and tapped the seal back into place, put the wheel on, then drove it a bit. I knew it was a bit low on fluid, but decided to mow some anyway. I wasn't wearing ear plugs as I usually do, but when I turned my head, I heard an unfamiliar whine, so I parked it. I drove 40 miles to the dealer and got 2.5 us gallons of SUDT2 (thank God I didn't get a couple of quarts). I figured I'd have plenty left over if we needed to do a change or something else leaked. I started adding, confident it wouldn't take over 2 qts. When I got to 5 qts, I started to fret a bit; at 7 qts, I worried more; at 9, I begged it to be up to the mark. It was. The amazing and scary thing is that the thing was still running fine (except for the whine with the pto engaged), on only 2 or 3 or 4 quarts. Granted, it wasn't doing any "work", but still. So, if your hst is anything like mine, that's not the issue. But, I suppose you should check- maybe when they are empty they act differently (a feeble attempt at humor)
