A slappy chain is a happy chain... well, not really, but people used to pure streetbikes have to be re-trained a bit. The DL needs a good bit more chain slack than a typical streetbike. Too tight can be VERY bad, while a little too loose is no big deal at all.
Make sure you triple-check this if you have a shop do any work -- they often set it like a streetbike chain.
2002 Suzuki DL1000 V-Strom, Dark Metallic Space Blue
1983 Suzuki GS850G, Cosmic Blue
2005 KLR685, Aztec Red - Turd II.2, the ReReTurdening