Help for two screw-ups B1550 fuel system

I made two mistakes and need help recovering. Any pointers will be appreciated.

The story:
B1550, 597 hours, bought new several years ago.

I started having engine cutouts and bogging down and quickly narrowed down the problem to a clogged fuel filter. My first mistake, I had cleaned the filter once but never replaced it and hadn't thought about it for a long time. Sure enough, when I took the filter bowl off, the fuel filter was covered solid with black flakes and gunk. After kicking myself, I ordered and replaced the filter.

Now second mistake. I tried to start the engine and of course it had air in the lines and I hadn't gone through the purging instructions that are clearly stated in the Work Shop Manual. I then tried purging using the vent on the fuel line after the fuel pump per WSM. I didn't get any fuel out of the vent valve while turning the engine though. I still tried starting it and it did kick off and ran for a while. I used the tractor a couple of times for an hour or so but then I started having the usual air in the fuel line symptoms, tractor runs for about 3-10 minutes and then starts stumbling. I would vent again and get it going and continue to run until I was finished with brush cutting or whatever.

Now this past weekend, I tried to cut grass for a while but it ran for 3 minutes and the venting procedure didn't fix it. So then I looked on line and found the procedure for venting at the injector fuel line connection and tried that. I did get some bubbles out of the 3rd fuel line (3 cylinder, third from the front). The other two didn't show much fuel coming out, just got a little wet even after I ran the battery down. I put jumper cables on the battery and tried some more but still no fuel out of the 1 and 2 cylinder fuel lines. Engine will not start at all now.

Question is, should I suspect more air anyway and try venting more, or did the clogged filter changing get some junk in the fuel lines? How to check each of these possibilities? Or is there another possible cause?

Thanks for any input.

Doug

Some good suggestions. Thanks D2Cat for a good detailed description of the process to get the lines cleared and find where the obstruction is. I'll get to that and cleaning out the fuel tank, hopefully this week. I'll start looking for the algaecide to add to my stored fuel since I do keep a couple of 5 gallon containers filled in my tractor shed most of the time. I've been adding Sta-bil for diesel fuel ever since I had the fuel filter gel up one cold, snowy day when I needed the tractor to clear a driveway.

Will let you guys know what I find.

Thanks. Doug

Found the biocide from Sta-bil at my Tractor Supply and will be getting a quart (expensive but with the small amount used for each 5 gal can it should last a while). I won't be able to work on my tractor this week since I've been called out of town, but will be disassembling next week. Thanks again for the replies.

Finally was able to get back to working on the tractor. I disconnected the fuel line where it goes into the fuel filter and got just a dribble followed by just drops and then nothing. I had a funnel with a ball of cheese cloth in the neck (very large funnel) and was draining the fuel into a 5 gallon gas (diesel really) can. When nothing came out, I sealed off the fill opening and blew into the fuel tank to give it some pressure. Sure enough, like many of you had thought, a big gob of gunk came out. (I actually thought it was a cricket at first, about the same size.) following that more smaller gobs came out until it started flowing freely and clear.

My next planned step is to check or change the fuel filter and then reconnect everything, bleed and then try starting the tractor. I thought about removing the tank and "wash" it out with kerosene but looking at all the interference items and the time it would take to get the tank off, I decided against it. I'll see if the fuel filter catches anything else by checking it frequently if the tractor does start and run OK.

Any comments on this plan of attack?

It will definitely help in future situations and I will make sure that I have a spare old inner tube (usually there's one hanging around somewhere).

Fired up tractor a few days ago and ran it for an hour in the morning with no problems. I didn't declare victory until today when I gave it a good workout with the bush hog for a couple of hours. It runs like it did when it was new. I'll be paying more attention to the preventive maintenance and filter changes.

Thanks again guys for the feedback and advice.

Doug