I bought this engine for $100 as a project. Came having been overheated, head taken off, 3 head bolts broken off in block. Resurfaced Head with sandpaper and glass, new head gasket, changed water pump impeller, and water pump housing, and lower pickup tube grommet, changed thermistat (old thermistat wouldn't open).
When drilling out broken head bolts, got off-center with 2 of them and drilled into water jacket, picked out threads, installed new bolts with sealant.
Runs great, good,even compression on all cylinders, pumps only a trickle of water and overheats.
If I remove lower unit and hook garden hose to pickup tube, cools and pees strong.
Have flushed water passages both ways, through thermistat opening, up thru pickup tube. Water seems to flow clearly, no debris.
Is it possible I have exhaust gas entering water jacket, building up pressure, keeping cooling water from reaching up to engine? This as a result of my off-center drilling? Compression is OK, though.
Leak in pickup tube?
Some unresolved issue with water pump?
Any thoughts as to narrowing this down would be appreciated.
Thanks!
When drilling out broken head bolts, got off-center with 2 of them and drilled into water jacket, picked out threads, installed new bolts with sealant.
Runs great, good,even compression on all cylinders, pumps only a trickle of water and overheats.
If I remove lower unit and hook garden hose to pickup tube, cools and pees strong.
Have flushed water passages both ways, through thermistat opening, up thru pickup tube. Water seems to flow clearly, no debris.
Is it possible I have exhaust gas entering water jacket, building up pressure, keeping cooling water from reaching up to engine? This as a result of my off-center drilling? Compression is OK, though.
Leak in pickup tube?
Some unresolved issue with water pump?
Any thoughts as to narrowing this down would be appreciated.
Thanks!