rusty handle bar under throttle :/

[raja777m]

I used these for few thousand miles, before selling the bike:
Motorcycle Black 7/8" Handlebar Hand Grips For Honda Suzuki Yamaha Kawasaki
I really love them, only problem is, you can't add bar end weights. You need to trim some excess pipe, but, the diameter is big enough, you can use OEM bar ends on it (once removed excess bits on the sides).
They are really comfy.

[TownsendsFJR1300]

I used these for few thousand miles, before selling the bike:
Motorcycle Black 7/8" Handlebar Hand Grips For Honda Suzuki Yamaha Kawasaki
I really love them, only problem is, you can't add bar end weights. You need to trim some excess pipe, but, the diameter is big enough, you can use OEM bar ends on it (once removed excess bits on the sides).
They are really comfy.

Cut the ends off!

Like Grip Puppies, remove bar ends, then slide em on!

[raja777m]

Cut the ends off!

Like Grip Puppies, remove bar ends, then slide em on!

The non rubber part is metal, so, we need more like a hack-saw or a rotary cutter, sand/file the edges and then put the bar ends, or just leave them as they are and use other types of fillers for the handlebars, to reduce vibrations(if they are still available).
One advantage with these are, they are pretty fat, compared to the thin ones on the OEM

[Pujazuba]

OK so today I managed to get the whole thing apart and do a decent cleaning job.
The metal part of the handlebar is in pretty grim shape. There was a very advanced level of rust and the metal had gone bumpy on the bottom part.
I lubed the cables from the top, cleaned the whole assembly, had to use sand paper on the handlebar to file rust off and smoothen it out. It's at least a lot better than before! Couldn't resist the urge of using a light amount of lube on the grip/bar. It slows down the advancing of rust.
Overall I'd say it rotates smoother. Nothing impressive, but from what I hear the throttle is tight on this bike so I'm happy so far.

That handlebar being so rusty in its underbelly really shows the importance of storing the bike away from the rain. Now I feel good about being bothered to keep the bike covered whenever I'm not riding it since it is constantly outside.

[TownsendsFJR1300]

The throttle is NOT tight on these bikes.

Sounds like you did good, especially with the rust. You can get a used handlebar on the forum and many swap bars for different styles.

Is the thin, plastic washer, at the INSIDE EDGE of the throttle grip VISIBLE and NOT inside the housing? If not, it needs to be.

Lastly, did you happen to simply move the inner cable to check for any binding? It should move easily.

Pic of my clutch cable, about 23,000 miles, ALWAYS maintained. I noticed the "slight" binding initially. Cut it open once the new one arrived.

[Pujazuba]

^Every chance I get I check the throttle on other bikes and right now they seem to feel less smooth and more tight than my FZs so you are right, they are not tight! Given that they're maintained.
And yes I have paid special attention to the thin washer as well as the cable insert in the above picture ever since I first saw it! Looks like that could spell disaster!