...In terms of reliabilty. I just got finished checking my 1999 yz400fs valves in my garage. My middle intake is too tight, and the other 4 valves are right on the edge of being too tight (Barely still in spec). Now, this will be the 2nd time that I've had to shim them in the past 6 months. What should I do? Should I just bite the bullet, and install all new valves and springs? I am already going to throw in a new timing chain for good measure. Even though the one in the engine is still fine. Here's some history on the bike. -Bought brand new in '98 by a guy who had nowhere to ride it, wife got unexpectedly pregnant, sold to who I bought it from. -Bought buy a dad coming off a 125, rode it for a while, then decided to go back to a 125 (The 400 was too much for him) -Then I bought it with very little time on it after my 125s crank went last April. The paint was barely worn off the frame. I changed the oil every 2 rides. I checked the valves in July, had to reshim all 5, the stock shims were still in the engine. I checked the valves again in September, and they hadn't moved. So, at this point, I think I am going to shim the one intake, then watch them like a hawk, and if they move I'll overhaul it. What do you think? Also, how much play should be in the timing chain when the adjusted is full tight? Barely any right? I have a pic of how much is in mine, but I can't find the cable to upload them right now. Thanks. Edit: After looking at my title, I feel it's a little much...LOL. I know that these bikes are supposed to be as reliable as rocks, and I am kind of dissapointed that mine isn't. At this point I am considering getting a 250 2-stroke too. So I don't know. Help me out.