Does your bike burn a bit of oil and blow blue smoke at startup? Goes away once its warm? Getting worse? Your valve stem seals are probably shot. Its not to hard to replace them. Heres how! Step 1 Remove the head as shown in my other how to: http://www.advrider.com/forums/showthread.php?t=419639 Step 2 The only additional tools you'll need to replace the seals are: Large c-clamp Stick magnet Pokey thingy Special home made tool! Small block of wood Lets start by making the tool. You'll need a 1 inch long piece of 1 inch square tubing. Cut down one side in the middle, then cut down one of the adjacent sides the same way, so you have a piece of metal that looks like this: This is your valve spring compressor. Pretty sweet, eh? Step 3 Get the keepers off of the spring! Place your home-made tool on the top of the spring. Now place one side of the c-clamp on top of the tool, and the other on the valve (with a block of wood or some other soft object between them) like so: (no block of wood in pick to show positioning- it should be directly on the valve head.) It helps to have a clamp that is very deep, otherwise some of the springs can be hard to reach around the fins. Tighten the clamp and compress the spring: Turn the head upside down and the two keepers should fall right out. DONT LOOSE THEM! The magnet comes in handy for picking them out... Slowly loosen the clamp. Remove the clamp. The springs (there are two for each valve, an internal and an external) should pull off and the valve should push out the bottom. Its generally a good idea to keep the same springs with the same valve in the same hole, so lay them out in order so you get them back together in the right place. Repeat for the other 3 valves. Step 4 Pop the seal off! Its the small green rubber deal with teeny spring wrapped around it. The pokey thingy works great for prying the seals off. Just be carefull you dont jab yourself or sratch something thats not sposed to be scratched! Step 5 Re-assembly. Since you've got it all appart, it might be a good time to lap the valves right now. Thats completely up to you. Lube the new seal and press it on. Time to put the valves back in- valve seated, springs on in same order/orientation they came off, home made spring compresser compressing the spring. Now you need some patience. Drop the first keeper in the hole. Use your sharp pokey thingy to spin the first keeper around to the back side, then drop the second one in. It may take a couple of tries, so use the magnet to fish out the keeper you drop... Loosen the clamp and remove the spring compressor. 1 down, 3 to go! Step 6 A simple test you can do to make sure your valves are seated is to tip one side (intake or exhaust) up and pour some liquid (gasoline, WD-40, etc) down into the chamber. Let it sit for a while and see if any is leaking out of the valves. Drain, dry, and repeat for the other side. If you DO have one thats leaking, try tapping on the spring side lightly to see if it will seat better. Assuming all is well, put the head back on and the engine back in!