00 Sprint Rs-kickstand Switch Issue

Seems a bit odd that, the sidestand switch should only kill the engine or prevent starting when the bike is put in gear. It’s the clutch switch that inhibits starting.
It could be an issue with crud in the stand switch causing a fault/short when down I guess. You’ll just need to remove the switch and give it a good clean out with some brake cleaner, they get covered in crud/chain lube etc.
I’m presuming you have a centre stand, that’ll make the job much easier.

 

The issue is NOT with your side-stand switch, it is with your NEUTRAL Switch
The bike requires either
a) the bike in Neutral
OR
b) the side-stand UP

Since your bike has no issue running with the stand up, it is clearly the neutral switch that is the issue

The clutch switch only interlocks the starter motor itself from running, has no impact on ability to actually fire and run.

 

Whether or not the transmission itself is in neutral is irrelevant (it obviously must be, or you could not run with the clutch engaged) - it is the switch that is the critical factor here and how well that contact is being made.
When the side-stand is DOWN it relies on the Neutral SWITCH being made (with good contact) - the side-stand switch has no bearing in the 'down' position.
The Neutral Switch is actually in the same area where the side-stand bolts to the engine casing - just slightly above that. - you should see a single wire going to it.
The same switch also feeds the panel indicator, but you may have a high resistance or intermittent connection there, even if looks like it's on (although flickering would certainly be a give-away)

p.s. the side-stand switch does not actually detect 'down', it detects 'up' or 'not-up' (which essentially means 'down' but in electrical logic terms down really signifies that it is not-up)
If bike is not seeing neutral, then it must see 'Up' to allow it to run.
So again if your problems are only when side-stand is 'not-up' (down) then it MUST be the Neutral Switch.

p.p.s. If it were the side-stand switch at fault, the opposite would be happening - it would be fine in neutral with stand down, you raise the stand, (still OK because it's still in neutral) and then you click into gear and it dies - THAT would be signature of side-stand switch not detecting 'Up'

 

Had a look through some Ebay pics for you

You can see it clearly here in this image
(between the side-stand mounting plate and the gear shifter shaft)

 

It is physically contacting the selector assembly when in Neutral - or not, when a gear (any) is selected. So yes, it is a 'mechanical' physical contact, creating an electrical path to engine ground.

 

You may find that if you jiggle the lever a little, it will become either worse or better, confirming the issue.

 

The neutral switch is worked by magnetism and over time the metal in the gear box wears this causes the switch to not pick up.Its Tiny amounts of wear, some people have reported success with a thinner sealing washer on

 

Gear change lever

 

Yes.drain the oil.