Mariner 5 HP Internal Tank Leakage Warning
Some gas leakages inside cowling has been reported on Mariner 5 HP, so will assume that on Mercury's, Tohatsu's and Nissan's 2 strokes engines too. The problem: during summer excesive's heat, pressure builds up on internal tank that leaks with gas through the hose that connects to tank selector control. The tank tube exit has a middle neck which is of inferior diameter as the tube itself, the only tie wrap available there doesn't hold well the hose against the tube, so with pressure will begin to leak.
Cut tie wrap with care as not to cut the gas hose, remove, place several wrapps of teflon tape until neck is completely filled and matches about same diameter as tube, cut, lubricate a bit, push hose in as was before. Secure tight with 2 tie wraps as shown on the pic, cut remaining end portions. The leakage is mostly experimented when engine is on transom with vented screw closed or when horizontal transported in car trunk.