Leaky Valve Guides

[Anonymous]

Hello. My 1983 GS750ES has an exhaust valve guide that leaks horribly. I removed the exhaust to confirm. It's the farthest one to the left. I want to stop the leak; it's embarassing when I'm cruising with friends in the cities with all of the blue smoke and everything. Should I replace the valve guides? How do I go about that and how long would it take. ANY input is most appreciated. Thank-you for helping so selflessly.
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[Don Lobacz]

You have to pull the head to determine if you need valve guides (usually not). You definitely need valve seals and this is a good chance to clean up the head and valves. Take a compression test before you get into it as you may want to do rings too.

[Billy Ricks]

You could try replacing just the valve guide seal first and see if that helps. If you replace the guides themselves you will have to pull the head. If you want to replace the seal you have to remove the valve retainer and spring using a spring compressor. You have to move the piston to the top of its stroke to keep from losing the valve in the cylinder. You can use compressed air with both intake and exhaust valves closed to keep the valves from dropping. They have special tools that you thread into the spark plug hole or one can be made using an old spark plug and some imagination. Knock the insulator out so all you have left is the metal plug base and use a piece of metal tubing epoxied into place to hook an air hose up to. If your careful you can get by just moving the piston to the top of its stroke. Remove the old seal, oil up a new one and careful tap it into place.

If you actually need new guides it is more complcated. You have to knock the old guide out from the inside of the combustion chamber. Then you have to refinish the guide holes with an 11.2mm reamer. Then oil each hole and drive the new guide into place. You then have to refinish the inside of the guide with a 5.5mm reamer. There are special tools for removing and reinstalling the guides and reaming the holes and guides. Also use one of the old seals on top of the new guide when driving the new guide in. Sometimes you are better off just replacing the seal, even pro's have been known to screw up replacing guides.

[JJ]

Another trick for keeping the valve against the seat while removing the retainer/spring... Take out the spark plug, and turn the engine until the desired cylinder is near (but not completely at) TDC on a compression stroke. Then feed in a length of small-diameter rope, about 1/4" or so, so that it is coiled on top of the piston. Be SURE to leave some rope sticking OUT of the spark plug hole, so that you can get it back out later! Then SLOWLY turn the engine until the rope is pressed between the piston and the valves. This will hold the valve(s) against the seats during the retainer/valve removal and replacement procedure. When finished, turn the engine BACKWARDS to move the piston downward, which will allow you to pull the rope back out. Viola!

Johnny
1982 GS1100GK