"I have a 38 hatteras with twi
"I have a 38 hatteras with twin detroits 6-71 485's A couple of months ago, I had the STB Turbo rebuilt. All was well. A day or so ago, while on a fishing trip, the RPM's on the same STB engine unexpectedly dropped from 1500 to 700 and after a few seconds, it kicked back up to 1500 emmiting black smoke. This RPM and black smoke fluctuation continued until I lowered my speed to 1000 rpms. Could it be that my Turbo went bad again? Or is this something new?"
"I have a 38 hatteras with twin detroits 6-71 485's A couple of months ago, I had the STB Turbo rebuilt. All was well. A day or so ago, while on a fishing trip, the RPM's on the same STB engine unexpectedly dropped from 1500 to 700 and after a few seconds, it kicked back up to 1500 emmiting black smoke. This RPM and black smoke fluctuation continued until I lowered my speed to 1000 rpms. Could it be that my Turbo went bad again? Or is this something new?"