mercruiser 5.0 low of oil

I have a 1995 chaparral 2130 with a mercruiser 5.0 carb chevy 305. motor has only around 25 hours and today i was out on lake running about 3/4 throttle and suddenly started loosing power and noticed my oil pressure was dropping so i immediately shut it down and rasied engine cover and noticed oil leaking and motor was smoking out of valve cover vent. had it towed in and when i got home was looking and the oil pan drain plug had vibrated completely out. does this boat have a low oil pressure shut off that would have caused the loss of power or have i majorly srewed the motor up. i did reinstall the l plug and refilled with oil just to be sure it wasnt locked up and it started up but didnt sound the best thanks Corey

Re: mercruiser 5.0 low of oil

Run it for a little while (on muffs) and see if it gets better. If you are lucky you just need to build up the oil in the lifters.
Just do a fast idle like 1000 RPMs. Until it warms up.

Re: mercruiser 5.0 low of oil

Ok thanks should I put some lucus oil stabilizer in it or do marine engines run to cool for that. Also what would explain the gradual loss of power does the oil pressure switch run to the fuel pump and shut it off

Re: mercruiser 5.0 low of oil

Loss of power was probably due to lifters not having oil, and not opening the valves. Or due to the high friction starting to gall all the bearings to the crank and cam. If it didnt seize up, and isnt knocking now, just clattery, try running it on the muffs and see what happens.

Re: mercruiser 5.0 low of oil

On models with an electric fuel pump yes it is safety connected to the oil pressure.

Re: mercruiser 5.0 low of oil

Well good news I took off valve covers and poured a little oil over the rockers and started it up on the muffs and it chattered for about 15 seconds and cleared up and now sounds back to normal.

Re: mercruiser 5.0 low of oil

Sounds like the lifters ran dry, and collapsed. Your responsiveness to the engines reactions might have saved you thousands!. It pays to pay attention! Dodged that bullet. I would pull the oil filter, and cut it open. Look for bearing material. Drain the oil as best you can. I like to suck it all out that i can, then pull plug and drain into a bucket. New filter and oil, then cut next filter open and see what it looks like. You might have a running engine with greatly reduced life?

Re: mercruiser 5.0 low of oil

well took it out on the lake this afternoon and everything sounds good execpt when i get it up to around 3000 rpms i can hear a ticking , sounds like it may be a rocker arm hopefully and not a main bearing. gonna take off valve covers tomm and check them what is the torque specs for the rocker arms 1995 305 chevy seems like i remember a long time ago i helped a friend rebuild one and it was tighten till they click then backoff a 1/4 turn not sure if thats right or not thanks

Re: mercruiser 5.0 low of oil

well just hooked it up on muffs and kinda sounds like the clicking may be coming from the outdrive