I own two, 1996 Royal Stars. Both of them appear to have a slipping clutch at higher rpm's in the higher gears. Neither one will creep if you start them in gear while holding the clutch, just top end issues. I have been advised that these bikes are notorious for "glazed" clutch plates, not worn. I was also advised that simply cleaning valve holes and changing fluid will fix it. I would appreciate any experience with this issue!!!!!

You need a new clutch, you completely fried it revving it to 4000 rpm while it's slipping

It is slipping. These big yamahas normally have slipping clutches. Mine slips, I've just learned to baby the clutch. Make sure you are in the most comfortable gear for the speed you are running at. Avoid rolling on full power at low speeds in higher gears. It's the nature of these great beasts. Clutch springs are too weak in these bikes, you may consider an aftermarket clutch spring assembly. The "shudder"(intermittent slipping) is caused by glazing. Make sure you are using the right lubricants for your bike, some synthetics can cause problems.

1)Adjust clutch cable correctly, check
2)Pull the clutch assembly apart, if there is little wear then you have "glazed" plates, clean each plate with 600 grit sandpaper and reassemble...get a new clutch spring assembly (weakened spring causes "shudder", slippage, and consequently glazing). Reassemble and adjust correctly (many forums out there with info).
3)Replace the full assembly and adjust correctly at setup. Adjust regularly....I check adjustment about every 300-500 miles.
4)Pay a shop to do these things for you.

the automatic transmission creeps? is that it?
that means the (brakes are dead) or the engine RPM is too fast.
if engine is cold (was it) the RPM can be and will be very high and will creep. so is it cold, the engine , and how cold, was it at time of creep
and what was the engine RPM.

or does e ofline mean off line or really means stalls.
as in, my engine when off line, like printer. or ?
wild guess there.

this is simple, all A./T have a clutch that has a stall speed
if you exceed that, RPM it does creep, that is how the a/T fluid clutch works. That is why say , when you idle a 800 RPM it dont creep
then you advance the throttle (engine rpm rises) there is a point
that car starts to move, this is the stall speed, threshold.
all normal.
this is why the operators guide has you start the engine brakes on
and trans in park then while holding the brake , you shift to drive
and prevent creeping,,,,,

If the engine starts with a good RPM but does not move when engaged in gear then it is possible that the CLUTCH is faulty and needs a change as it is slipping.
If there is no higher RPM when the accelerator is pressed then the engine needs a tuning. The electrical section for ignition must be checked specially the timing and also the fuel supply and pressure.

If it's the original 1996 clutch I'd be surprised if it wasn't slipping. If the clutch & clutch springs are actually still good & working properly, make sure the oil you're using doesn't contain any "friction modifiers". AMSOIL & other companies make synthetic lubricants without friction modifiers. If your oil or an oil additive has friction modifiers, just drain the crankcase and replace the oil with the proper stuff and that may well cure the problem. Replace the filter too.

converter came loose

This is simple your going to need transmission work replacement of gears and shift fork or forks as needed after inspection, and a new clutch plates and springs.

it sounds like its slipping, a burning plastic smell is a good indicator of a slipping clutch.but it may just need an adjustment, plz rate-bozcro

It seems as though the Transmission clutches are slipping if it's an automatic or the clutch is worn if it's a standard. If it's an automatic transmission check the Transmission oil it should be clean and no burnt smell. You will easily recognize burnt oil by it's nasty smell.

The fluid and speed sensor did not really do anything to solve your slipping problem. If it slipped before it could be that there are chips/breaks in the teeth on the gears or it could be that the clutch is not connecting when it gets into higher gears. May need a new tranny or clutch.