I understand what mtnviper is saying and he is correct, but we are not talking about having slack in the chain, just about how much tension should be placed on the chain from the top sprocket to the bottom sprocket, if ya use the 3/4-1" freeplay method it will work flawlessly.
I bought a 2001 srx off a guy brought it home, never rode it didnt need to it only had a few hundred miles on it, was almost new yet and did all the usual mods I do to them, porting,clutching,jetting, oversize wheels in skid, I usually always stick with the stock gearing on a 121" tracked srx so I never opened up the chaincase, anyways, after I completed my tinkering on it, I took the sled out for a test spin and mashed the gas wide open, let off... and almost ate the handlebars, the sled slowed down so rapidly it was just like the brakes were hanging up. Took it into the shop and checked the brake caliper and pads, they were releasing and were not hanging up, but with the sled on a jackstand the track was almost impossible to spin by hand, opened up the chaincase cover and low and behold if ya would have tapped the chain with a peice of steel, would have sounded like a tuning fork, it woulda rang a high note, that chain was banjo string tight in there, so tight it ruined the gears and chain, after replacing the whole works in there and cleaning out the metal shavings she was as good as new and had a whole lot more speed to it. too much tension will slow the sled down when you let off the gas from added drag of rolling resistance around the sprockets. Thats why I like to adjust them with the cover off, once a year I take off the covers and cange the chainlube out anyways, always good to make sure everything is up to snuff in there, nothing ruins a nice ride quicker then a break down.
