Is the trailer hitched to the bike? Some need to be hitched for a good ground.

There are 2 hoses connected to the air box. Both toward the rear of the box. Pull those off and the air box should pull right out.
Pictures would help us help you.

#1--Sounds like an add on by the P.O.

#2-- 7/8 yes

#3--no idea about the valve. It does get taller.

#4--Most put a spacer on top of the spring.

Earl is correct.

The diode is located inside the tape from mother Honda. It is on the left side about 2 inches in, behind the regulator.

Glad you got it running. Show us a pic ...

Glad you survived your ordeal. Do not use fiberglass to fix it. Fiberglass will not stick to the fairing plastic. Get some black Oatleys plastic pipe cement and black plastic pipe . Shave some pieces off the pipe and mix in some cement to make a slurry solution. If you can not find the Oatleys then ...

go to top of page and hit manuals. It shows how to test thermostat etc...

When I put the rocker's on I torqued them to 20 ft. lbs. He untorqued the 6 bolts for the rack to 15 ft. lbs. This allowed us to turn the engine over with no catches.

Believe it or not but I am having the exact same problem with my left head.
2 Springs broke on the valves. Now I can not get past a spot when turning the crank.
Will let you know tomorrow on what my mechanic does.

When you changed the timing belts did you check the valves intake and exhaust? That made my bike perk up a lot.

They are chromed plastic.
They have a clip behind them and they attach to the lower fairing.

That would be real nice to have. How many before me??

floor boards and shifter?

floor boards and shifter?

80 81 front caliper piston 45107-415-006 82 front caliper piston 45107-ma3-006 80 81 rear caliper piston 45107-415-006 82 rear caliper piston 45107-ma3-006 83 front caliper piston 45107-mb9-781 83 rear caliper piston 43107-ma7-006 google the part #'s and find the specs on the different piston sizes....

I am looking for the floor boards and shifter for my 82 wing. If I find them you can have the pegs off of my bike.

That wire sounds like the neutral switch.

Change the belts ASAP.
Also write the date and mileage on the inside of the belt covers.

Go to the "manual" at the top of any page. Follow the wiring diagram.

The plug by the left knee is where all the fairing wires lead to, including the ground.

WOW!!!
I did not know there was a GL1200 in the year 1886.

Have you had the battery tested under load? Napa will check it out.Check the easy and cheap things before pulling an engine.

Most parts are interchangeable on all gl1100. The tires and brakes are a little different on the 4 models.

NAPA # 7733 Hose.

Take the hose you cut off the bike and cut this NAPA hose from your old hose for length. You have both the upper and lower hose

Replace the left side and ride it.

15 bearing, radial ball, 6204u 96140-62040-10
16 bearing, radial ball, 6304u 96140-63040-10