89 70hp yamaha runs rough from water in fuel

[jee352]

I have a 89 70 hp yamaha w/ approx 50 hours since rebuild. started running rough & i found water/rust in fuel system. completely went through fuel system including carb rebuild. now im running out of a 5 gal container. it fouls out plugs and seems to still have rust in the engine. ive flushed the cylinders w/ mineral spirits & im still getting rust. im thinking ive got a blown gasket or could this be residual from the contaminated tank?

[jb123]

compression test it

[jee352]

thanks sounds like the next step

[jb123]

sounds like you may have a bad gasket SOMEwhere... maybe from the rebuild or the block/base mount.

[jee352]

i have an even 120 psi compression on all cylinders. removed part of the cowl for the mid section & inspected the block base gasket & it looks ok externally but it could be blown internally any more suggestions? Im trying to limit the disassembly

[jee352]

pulled the pwrhead to rebuild. has anyone come across someone that can replace the bearings on the one piece pressed crank?