A year ago or more there was a lot of chat here about chain slack. Many claimed that the official Handbook slack measurement was far too tight, giving rise to a constant, annoying whine under way. Solutions offered seemed to be around increasing slack to 20 – 30mm. I personally found this helped greatly.
 
Is this still an issue on later bikes, or have Yamaha’s instructions and/ or ex-factory chain-slack settings changed?
 

I picked up my FJ a couple weeks ago and the salesman told me the mechanics at the shop like 1" about 25 mm of slack. That is what it was set at when I picked it up.

I run mine at about an inch of slack. Stock setting is ridiculous and will damage bearings to my knowledge.
 
Cheers

The manual says to adjust the chain to their spec while the bike is on the center stand, but even set at an 1-1/2" of slack when I have the bike setting on the side stand the chain tension seems tighter than it should be.
 
Wouldn't it make more sense to adjust the chain with the bike on the side stand?

The manual says to adjust the chain to their spec while the bike is on the center stand, but even set at an 1-1/2" of slack when I have the bike setting on the side stand the chain tension seems tighter than it should be. 
Wouldn't it make more sense to adjust the chain with the bike on the side stand?

 
 
I adjust on the center, and then check it on the side stand. Repeat as necessary. I like mine between 1 and 1.5 inches.

When I first got the bike and saw the manual spec I was a bit alarmed as I had about 1" of slack. After checking with 3 Yamaha dealers and two mechanics I know and trust, they all said the manual is crap. They haven't fixed it in more recent manuals afaik.

And the FZ1 manual says check the slack on the side stand - the wheel is on the ground, not in the air.