From your stated desires, it is unlikely that you will ever like the Cb550 brakes. Even when you get them to lock the front tire while dry, they will still be different and have less power when wet. Water acts as a lubricant between disk and pad, reducing friction. It's both good and bad, really. I never thought locking the front tire as a good thing, as this tends to get the sides of the bike scraped up from sliding to a stop on it.
The front brake light switch is located in the hydraulic pressure line on the lower triple tree. See, if it is still connected.
In traffic, I tend to ride the front brake to squeege off the water and keep the disk hot. This allows you to retain about 1/2 to 3/4 of the brake effectiveness. Remember, your tires don't have best traction in the rain either. And, the rear brake still works well enough to lock the rear tire in the rain. I prefer to keep the tires rolling. After rebuilding the front brake, replacing the fatigued,expanding rubber front brake lines with braided SS, was the best performance improvement made. I suspect wet performance would increase if you either drilled rotor and.or cut some channeling grooves in the brake pad. But, I just allow extra time and space while driving to compensate for wet riding conditions.
Oil change:
Get your self a 6 point, tight fitting socket for that oil filter bolt. And pray that it wasn't overtorqued by the previous filter changer. Alternatives will leave you proclaiming expletives.
Spark plugs for the CB550 s/b D7EA. D8EA will make the bike very cold blooded.
Carburetors:
You'll hate removing them from the bike. Most do, until the technique for extraction/insertion is learned. It is possible to do much of the cleaning with them in place, though. You'll have to be limber, clever, devious, and determined to do so, though. But, check your tank for rust first. Cleaned carbs only remain so if fed clean fuel. The 75 petcock has an in tank full screen that can easily be damaged and then let pass debris that can cause the carbs to overflow.
If your tank and in-tank filter check out, then you might consider dropping one of the outer carb bowls, in order to see what kind of glop is inside them. If foreign ,material will spray off with carb cleaner, you can probably clean them in place. If you have white corrosion deposits inside or hardened residue that is difficult to dislodge, then you are better off with bench maintenance. Do get some carb kits from Honda and don't whine about $18 a carb for them. You're saving over $300 on labor, aren't you?
Split, leaking fuel hoses are best replaced. Get 5 mm fuel line in bulk from the Honda dealer.
Ticking noise:
Argh. You could be describing the dreaded cam cover rocker wear. I've described this and the repair in detail elsewhere in this forum. Search. And, have the crying towel handy. Maybe your parts bike will bail you out. Maybe you should peruse eBuy for a 77-78 CB550 Cam cover, rocker arms, and cam. If you can feel the ticking at an inspection cover...weep.
Electrical:
Unless you describe the mods done from the vetter install and removal, it is best to simply point you to the stock wire diagram. The closer your bike reflect this diagram arrangement the more likely it will work like it did when new.
Work order:
Leaking gas is a fire hazard. I think I would address that first. A burned bike and surrounding area can ruin more than just your day.
Electrical would probably be next, for operational reliability.
A full tuneup.
Chain lube/adjust.
Fork oil change
Improve your brakes, or learn to cope, next.
Address the ticking.
I also have one of those 700SCs. It's a pretty nice bike now that I've taken care of the "little things" that had been allowed to deteriorate. It's kinda spoiled me. Shaft drive= no chain lube, adjustment or replacement. Hydraulic valves= no frequent tune-up. Electronic ignition= no points or timing adjustments. I still have to change the oil and put gas in it, though.
Dual disk front brake works pretty well. I haven't encountered rain with it yet, But, the drilled rotors should help keep it effective. I'm not at all sorry about the money I've spent on it since it was given to me. In the picture you posted, yours doesn't seem to be in bad condition. It's quite a bit faster than the 550 and gets to its 10K redline scary fast.
If you can take the lock off and get to a locksmith, they should be able to make a key for it. Good ones will anyway.
Cheers,
