I picked up a 91 Suzuki DT25 that had overheated. Owner had pulled head and broken off 3 head bolts. I drilled out bolts and rethreaded, replaced water pump and thermostat (old one would not open) cleaned carbs, fuel filter,flushed water passages, new head gasket.
On hose engine would not pee and would start to get hot.
Removed lower unit, hooked garden hose to water pick up tube with lower unit off , engine cools and pees fine.
Put engine in lake, weak, dribbling, pee stream, good water flow from exhaust port, initially, them engine temp continues to climb, (based on leaving hand on head), then water from exhaust port turns to steam and have to shut down. Head is too hot to keep hand on.
I did not machine head at all when I reinstalled it.
When drilling out the head bolts, I got crooked and drilled into water jacket to side of head bolt hole at the bottom of hole. With new head bolt installed, I believe this hole is effectively plugged.
Question: Would a warped head, cracked head, head gasket leak, cause this overheating?
Should I try to seal my mis-drilled hole with epoxy?, rethread and reinstall?
I am leaning toward a warped, bad head, but only a guess.
I don't think it is water pump related, I ran the motor, with the themostat cover off, in the lake and it gurgles good water out of the themostat cover hole when running.
All help appreciated!
On hose engine would not pee and would start to get hot.
Removed lower unit, hooked garden hose to water pick up tube with lower unit off , engine cools and pees fine.
Put engine in lake, weak, dribbling, pee stream, good water flow from exhaust port, initially, them engine temp continues to climb, (based on leaving hand on head), then water from exhaust port turns to steam and have to shut down. Head is too hot to keep hand on.
I did not machine head at all when I reinstalled it.
When drilling out the head bolts, I got crooked and drilled into water jacket to side of head bolt hole at the bottom of hole. With new head bolt installed, I believe this hole is effectively plugged.
Question: Would a warped head, cracked head, head gasket leak, cause this overheating?
Should I try to seal my mis-drilled hole with epoxy?, rethread and reinstall?
I am leaning toward a warped, bad head, but only a guess.
I don't think it is water pump related, I ran the motor, with the themostat cover off, in the lake and it gurgles good water out of the themostat cover hole when running.
All help appreciated!