[Paul Witt]

Can anyone give me some information on replacing the lower crankshaft seal on my 98 Evinrude 115. It seems this must be my mysterious oil leak, I've checked everything else.

[Solittle]

Where do you observe the leak? If it is comming out of the lower unit it may not be a leak at all but oil from unburned fuel - normal for a 2 cycle.

[Paul Witt]

It will leak down the lower unit from under the cowl. I thought it might be the carbs leaking, and by the time it got down to the lower unit, the fuel had evaporated. No luck, I've already rebuilt the carbs. It will leak the most, just sitting in the driveway. After a couple of days, It will be down to the prop. The upper crankshaft seal has already been changed. It doesn't seam to be leaking from the block seam. The only thing else I can think of is the lower crank shaft seal.

[Dhadley]

It may be a base gasket leaking or a crack in the mid section in the exhaust area. If the lower seal was leaking it should leak into the mid section near the top mount then find its way to the outside.Its fairly easy to pull the powerhead and change the base gasket and lower seal. At that time you can inspect the exhaust area for cracks. They usually are in the front starboard corner.Good luck!