Could someone clarify chain tensioner / tension? 99 750 dark

[memper]

The screws at the end of the swing arm, do they only push the axle forward? Or do they draw the axle back as well?
Also, I read on the swing arm to set it at 20 to 25 mm. Even 25mm seems tight to me. Mine is about 40mm and the top run of the chain just barely touches the bottom of the swing arm.
What is too loose? I have seen some race bikes with seriously sagging chains at the track. Is 40mm too much??
Thanks

[ducpainter]

The screws at the end of the swing arm, do they only push the axle forward? Or do they draw the axle back as well?
Also, I read on the swing arm to set it at 20 to 25 mm. Even 25mm seems tight to me. Mine is about 40mm and the top run of the chain just barely touches the bottom of the swing arm.
What is too loose? I have seen some race bikes with seriously sagging chains at the track. Is 40mm too much??
Thanks

If the rear ride height is stock, then 25mm is correct...40 would be pretty loose.

If the ride height has been altered you would need more or less depending on which way you adjusted the height...higher ride height needing more.

Make sure you find the tightest spot on the chain to set your free play.

[battlecry]

Memper, the bolts screw into axle carrier plates that ride inside the swingarm.  So they do move the axle forward and back a small amount, but you do not need much. 

I tend to loosen them up somewhat and bump the tire with a rubber mallet so it seats forward, then bring the axle back into spec and alignment by screwing the bolts.  If you haven't done this yet, I'd recommend you pull the plates out, unscrew the bolts and lather them in anti-seize compound.  The plates and the bolts will corrode into a fixed mass after some time and rides in the rain. 

[memper]

Ok thanks guys. I just checked it again, and while on the side stand it read about 38mm.
When I get a chance I will tighten it up some.
Thanks on the anti-seize tip. Didnt even think of that.

[H-2 CHARLIE]

 Always check free play why sitting on the bike .

[Howie]

Always check free play why sitting on the bike .

Always check by manufacturer's instructions if stock ride height:
Chain tensioning
Turn the rear wheel slowly until you find the position
where chain tension is highest.
With the motorcycle on the side stand, push the chain up
pressing with a finger at the point where it intersects
with swing arm centerline. The lower portion of the chain
should have a slack as follows (fig. 33.1):
20-25 mm (600/750);
25-30 mm (900).
To adjust chain tension, slacken the nut (1, fig. 33.2) of
the wheel spindle. Then tighten similarly the screw (2)
clockwise on both sides of the swing arm to increase or
reduce chain tension. If you are slackening the chain, you
will have to push the wheel forward.

On a rear stand will work too.

[memper]

Thanks and will do. I have to replace my master link anyways(squished it a tad much on the install). So I will adjust properly at that time.

[MadDuck]

Always check free play why sitting on the bike .

That is, after setting properly according to factory procedure, have someone close to your weight sit on the bike and check the play again. A little loose is better than a little tight but you don't want to go to extremes.