Welcome.
You may have to wait for answers on this site. It's slow because many members no longer here and those of us left are old (not lying).
Like you said, tremendous amount of info on this site and it seems you have been looking.
I will post some PDF stuff for you below to download and other stuff. It may seem over whelming.
To answer your questions:
1) Wheels -- I don't know the answer
2) Axel -- #42310-950-000 -- It's only used on the FL250's based on service Honda
3) Fuel pump -- this is critical, like you said. Since you don't have a starter you can test it like the FL400 manual says. However I don't like this method because of fire hazard. You start your machine to make sure float bowl is full of fuel. Then shut it off. You pull the hose off the carb (attach longer line ??) and put it into a measuring container that has OZ markings. Now you start machine for 10 seconds (use a stop watch) and shut it down. You need 4.5 oz in 10 sec approx. If you got 4 then you're probably good.
Please remember your machine must start at the lowest idle possible without stalling and the stop watch starts as soon as the machine starts. CAUTION FIRE !!!Next important info:
1) The best way to find something here is to use the search box above.
In the search box type ONE word ONLY and hit enter. If you don't you will get to many hits.
When the list of threads comes up there will be another search box there on the right.
In that box type ONE word ONLY. Keep doing this as many times as you want until you have narrowed it down. Some common words will be ignored like "Engine" "Honda" etc.
Also at the very bottom of any thread you read will be an area where there a similar threads to the one you are reading. You can click on them to read.
2) Honda FL250 serial numbers:
1977 FL250 1000001-1011921
1978 FL250 1100001-1112345
1979 FL250 2000001-2012620
1980 TB04 2000001-2006315
1981 TB04 BC400001-BC406324
1982 TB04 CC500001-CC514700
1983 TB04 DC600001-DC617555
1984 TB04 EC700051-EC703225
3) Searching for parts:
Below is a pdf of the FL250 parts book. What you do is copy the part number and then go to service honda. Here is the link:
https://www.servicehonda.com/error/notf ... rts/lookupIt will come up "page not found". That don't matter. Click on "factory parts". Click on "Honda". Click on "FL models". On the right side is a search box. Enter the part number you are looking for and hit enter. On the list that comes up there will be a small highlighted area that says "where used". Click on it. It will tell you if that part is used on any other machine.
4) I don't know if you have a manual but I will try to attach it below. Hope it works. If not I will provide a link for free download. (I couldn't add the manual). Here is a link:
https://oddatv.com/fl250-fl350-factory-manuals/ 5) Be patient. Nothing happens fast on this site.
CO