It would really help us out if you would identify exactly what you have (unless you don't know and that's the reason for your post).
Simply stating I have a 2001 150 horse leads to many follow on questions.
In 2001 Merc sold a 150 2 stroke, a 150 Optimax and a 150 4 stroke.
They are mechanically very different and what might cause "this" to happen on a Opti would not be anywhere near what would happen on the 4 stroke.
So do us a favour and save yourself some time (especially if you want a quick answer) and identify your motor as completely as possible when you post...
"I have a 2001 EFI 150 2 stroke that had the oil injection bypassed" is an excellent way to start your post
Simply stating I have a 2001 150 horse leads to many follow on questions.
In 2001 Merc sold a 150 2 stroke, a 150 Optimax and a 150 4 stroke.
They are mechanically very different and what might cause "this" to happen on a Opti would not be anywhere near what would happen on the 4 stroke.
So do us a favour and save yourself some time (especially if you want a quick answer) and identify your motor as completely as possible when you post...
"I have a 2001 EFI 150 2 stroke that had the oil injection bypassed" is an excellent way to start your post