Took a vacation day today to tackle a very small coolant leak on the 400. Whenever it sat for a while- especially if it was really cold, there would always be a drop or two right under the water pump. I had ordered all the O rings a while ago and a used pump off of ebay as well. Today i ripped into her. Because you have to drain the oil as well, she got the full service. Finally got teh old pump off. All teh o rings were flattened out, glad i have all new ones. Have a look at the pump and discover that at some point in the past, someone has attempted a rebuild by pressing in a new shaft seal. Problem is, they didnt push it in far enough and the impeller has been slowly machining the housing down inside. Sure enough, after dumping the coolant out of the pan, plenty of little aluminum particles. Look at my ebay pump and it looks perfect, so in she goes. Got her all closed up, coolant and oil refilled, and took her for a good rip. Everything appears oil and water tight. Bike may be running just a bit rich in the bottom/mid, so tomorrow i am pulling the carbs again and playing with the mixture screws.

Cool - good job