my 81 650C with 9000 miles, It has a leaky head gasket I think. I cleaned the fins and put flour on the fins and discovered after running it that there is a one half inch wet spot in the center of the seam between the head and the lower case on the left side of the engine. Is there any way to stop this leak without a new head gasket? I run 10W30 rotella synthetic . The leak stopped for about a month after I went on a long trip to the mountains at a constnt 60 to 70MPH but now it is back. The leak is more ugly than anything else. Otherwise the bike runs flawlessly. I ride it to work almost everyday 34 miles round trip and it is mostly city stop and go.I Add oil when the stick gets down to half way on the dip stick. A few ounces tops it off. Can I do anything to help the situation?