Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi all died after a raft they were on collided with another raft and flipped at the Gold Coast theme park.
A malfunction in a water pump on the ride had caused water levels to drop, contributing to the disaster.
It was the third time the pump had malfunctioned on October 25, 2016.
Dreamworld's engineering supervisor Peter Gardner has told the inquest that park procedure should have meant the ride was shut down after the second pump failure.
Counsel assisting the coroner Ken Fleming QC asked Mr Gardner how many times a ride had to break down before someone says "enough is enough".
"Before a review is taken, it's twice ... twice in the same day," Mr Gardner replied.
"That ride should not have been in service after it broke down the second time should it?" Mr Fleming then asked.
"No," Mr Gardner said.
The inquest also heard wiring described as a "rat's nest" with a potential for serious malfunction in the ride's main control panel was "not of a particularly high standard" in Mr Gardner's opinion.
He said had he been aware of the state of the wiring he would have raised it as an issue.
Dreamworld electricians have already told the inquest they had mentioned their concerns about the wiring "multiple times" and believed the control panel was due to be upgraded before the tragedy.
Electrician Quentin Dennis said he wouldn't let a mechanic reset a ride's pump, as happened on the day of the tragedy when the ride's south pump failed twice before a third malfunction contributed to the fatal incident.
"No, I wouldn't show them because they don't have experience on drives on the electric side of things," Mr Dennis said.
Mr Dennis also expressed surprise when he was informed an emergency stop button on the ride's control panel only stopped the ride's pump and not the conveyor.
He said to his knowledge the button should have shut down the ride completely.
The inquest continues.
