My motorcycle is way underpowered?

You wanna go fast eh?

Has the bike always been like this or is it a new thing?

Check it's running on all four, my old gs was a prick and ran on three until I gave it some gas then no.4 would cut in and she'd be right.

Ok I reckon you have to look at your brakes to make sure they're not binding. Then...

Clean out your air box/filter and make sure the carbies are getting full fat. Open the carbie floatbowl drain plugs and run out ll the crappy fuel with the tap off. Then turn it to pri and let the fuel run out clean. Then tighten her up.

If you have the model with the cv carbies, check the diaphragms aren't split

If you can do a comp test then do so.

Fit new plugs and check the leads from the coils are n't breaking down at high revs

Get the mouse nest out of the exhaust.

Lose weight if you're not "aerodynamic". The Gizzy is a good ole donk but it can't do miracles. That's a job for Jesus not GS's

First give it a complete major service.That would cover almost every routine aspect of the bike and without doing that, you don't have a clear baseline.

Then if the problem persists, you can do compression checks, clean the carbs (internally) and look for weak spark, air intake leaks, fuel flow restrictions and so on.

I'd also check the twist grip isn't stopping before full throttle, and check the throttle cable and even the sprockets are standard. Someone could have fitted the wrong ones.

Clean the carbs. A real cleaning involving disassembly and blowing out every jet and orifice. Do a compression check. Make sure everything in the book like valve clearance and cam chain tension has been done. Clean the petcock screens. Replace the air filter if it's old. Check the timing and make sure the vacuum advance is working. Make sure the brakes aren't dragging.

At 33 years old I'd check the cam chain , heads and pistons . Check the timing and do a compression and leak down test.

Carbs could be dirty , maladjusted or out of sink as well your air filter might be choking the intake.

Weak spark ? coils , ignition , plugs , plug wires and charging system.

There , that should keep you busy a few hours.

The GS engines really, really hate not being connected to their airbox, if you have cone filters that could be the cause, so could damaged/perished rubbers.

Smear washing-up liquid around the rubbers and run the bike you should be able to spot any air bubbles.

I would look for good compression and intake leaks. They could cause it to run with less oomph than it should. Are the cabs synched properly? That could reduce performance as well.

One of the most problems is the battles, remove them, pour gas on them, set on fire to clean them out. That should take care of the problem, if it doesn't, it may need a tune-up. riding 49 yrs