Honda BF20A-BF25A, BF25D-BF30D Outboard Motors Shop Manual., Page 241Get this manual
4APPLYING LIQUID SEALANT Apply liquid sealant (ThreeBond #I 21 1, #I or equiva216 lent) to the engine under case gasket and oil pan gasket as follows: Apply aboutmm (0.040.20 in) widtha Assemble the engine under case and oil pan within the specified time after application of sealing agentExample:Within 90 minutes when using ThreeBond #I21 1- Within 30 minutes when using ThreeBond #I216a Wait for 15 minutes after assemblyDo not add oil during this period
ENGINE UNDER CASE GASKET LIQUID SEALANT Apply sealant about APPLICATION AREA mm (0.04 0.20 in) in widthon both sides-
ENGINE UNDER CASE GASKET
1) Clean the cylinder block and engine under case mating surfaces and clean new gasket with degreasing cleaning agent and clean shop towel2) Apply liquid sealant to both sides around the exhaust passage (i.eposition shown) of the new gasket