I always check my chain tension on my ktm's while I'm sat on the bike... It's really loose when your not on the bike but when you sit on it with the suspension compressing it tightens up loads. I've always done that, rather have my chain loose than tighten it to the correct tension with me not on the bike then when I'd be on the bike it'd be solid and would put a load of strain on the gear box. I have a ktm 525 exc 2006 and a ktm 450 2004 exc btw. Great bikes. Changed my top end in the 450 at 250 hours for a hi comp piston now at around 500 hours and not had a single problem with either bikes. Only changed top end on the 450 for peace of mind didn't need it