1987 150hp Black Max Oil line failure

Just purchased bass boat with 150 HP BM. Oil line between pump and mixing valve blew and we lost power. Fixed line but was idling poorly, checked compression and all were good except #6 cylinder which had 75 PSI. cylinder was scored and powerhead is being rebuilt. Just wondering why #6 would go first and not the top cylinders which should be the first to run without oil??

Re: 87 Black Max oil injection failure

Cylinder 6 was probably the "weakest" of the bunch, plus maybe running a touch hotter than the others (which combined with the lack of oil just killed it a rotation or two quicker than the others would have died).

The firing order may have contributed as well - dozens of factors including just a slightly clogged jet for that cylinder which made a bad situation worse, further restricting that last reminant of oil from getting to the cylinder.

You should have really titled your thread "oil line" failure - you are living proof that a 23 year old Merc oil pump is still running fine - it was the "cheap rubber" hose that died...

Re: 87 Black Max oil injection failure

Thanks for the quick reply, hopefully it will be back in the water by next week as we are heading not far from you to Charleston lake. There turned out to be a ready to go upper bearing malfunctioning alarm and bend prop shaft so everything is getting done. Hope it lasts another 23 years.