Drain hole stopped up?
The reason the plug is recessed on that side of cylinder is the cam chains are on that side, on the front cylinder it is the other side. If there were only 2 plugs they would probably be on the other side of each cylinder where recessing them would not be necessary. When you remove this tube there are two o-rings you should replace so you do not develope an oil leak. There is a drain passage to the rear of the rear cylinder and one to the front of the front cylinder, these need to be clear so water can drain out of the tube. Your rear one must be stopped up to allow water to sit and cause such corrosion. I would use a small skinny screwdriver to loosen up as much crud as possible then run a small wire through drain passage and vacume it out before I removed spark plug or the tube. When you have removed the tube you can clean it much easier. The rear axle nut does fit into the tube to unscrew it. You could also use compressed air to blow the crud out of tube and passage, be sure to wear eye protection! Putting it back together is just the reverse of removing it. Try to insure that nothing gets into the spark plug hole or the engine while doing this!! One place to get the proper o-rings is BikeBandit.com Part numbers are 92055 31mm & 92055B 27.7mm if you get them there. A dealership would want Part numbers 11028-1085 31mm & 11028-1097 27.7mm, or at least the dealer where I live did. Of course the dealership did not have them.
Last edited by Jeff Barnes; 04-02-2012 at 05:17 PM.