2001 0x66 250 TURZ Multiple Blown Head Gaskets

[bonafishark]

Need some direction if possible. Never had any issues until couple weeks ago. Temp alarm and overheat at low RPM's after running for 15 minutes down the canal and right before throttling up. Block looked like it got hotter than should have before the alarm sounded, some melted wires, browning of the block, etc. Tested thermo switches and they functioned fine. This overheat caused (Im guessing) the head gasket to rupture on the left bank between 2 cylinders. Replaced the head and cover gaskets-no sign of warpage/pitting or scoring- water pump/impeller-old one looked fine, new plugs-PRV and Tstats. Did find one Tstat that was stuck open, maybe it could also have been stuck closed. Engine ran fine for couple outings than she started having slight surge issues through the RPM range and eventually full power loss. Head gasket in similar spot on right bank blew. Replaced the gaskets, no visible sign of damage to cylinder, did not get any heat alarms this time. Also replaced the low pressure fuel pumps and all the fuel lines. Same scenario-she would run fine at first, than start surging up and down the RPM's and than eventually power loss. One quick overheat for couple seconds but instead of the temp gauge blinking it was the oil bars blinking. The head gasket in the same spot on the left bank blew again. Need some help in the right direction. One thing I have noticed is excessive oil consumption for month or two prior to the issues, maybe 30:1 if Im lucky. Checked and readjusted the Oil Pump Linkage. I feel like Im still battling the same issue that caused the original overheat, although half the time it feels like fuel starvation issues. I dont think this would cause multiple ruptured head gaskets but I could be wrong. I did run Ring Free for couple of fill ups. The new plugs do get dirtied pretty quickly and seem to be carboning up fast.
Any thoughts appreciated. Any additional info will be supllied quickly. Thanks

[bonafishark]

Also screen was clear and clean in the VST along with the small screen in the pressure regulator.

No ideas boat.net?

[boats.net]

Need to take heads to machine shop to have resurfaced and check cylinder block with a straight edge to see if warped, check small water passage holes around cylinders. If got hot enough to melt wires may a wire shorted somewhere.

[bonafishark]

had the heads cut, no warpage evidence on the block. All water passges were clear. Did have a melted wire, coincidently the thermo switch, that I have since fixed. Is it possible that running too lean for an extended period of time would cause these gaskets to fail? Where should I start with why it is running lean. I did have air leaking into the line from after I changed the pumps from a cracked hose. Oil pump link rod setting looks ok. Throttle vales in synch.

Thanks

[boats.net]

Running too lean usually will melt piston before it blow a head gasket, need to check fuel pressure and injectors are ok.

[jb123]

when you put the heads back on did you ever do a comp check ? possible you may have a water leak/corrosion and compressing water blows gasket ??