merc 150 remote oil tank/alarm - rookie question

[dcohan]

Sorry, got a rookie question:<br /><br />I recently got ahold of a 10 year old 19'6" Grady White with a Merc 150 BlackMax engine, also 10 years old (has been on the boat since purchase). According to the previous user the boat has been running without a hitch for a decade. (drumroll)<br /><br />About a month ago the gasket at the top of the remote oil tank broke and was replaced. The tank is under aft the seat. Two weeks ago I was out for about 4 hours, after about 2.5 a very loud steady alarm started to sound from the dash. After stopping the boat and restarting the alarm went away. The next day I took the boat to get gas, and after filling up and heading for home, the alarm sounded again. I restarted the boat but had the alarm go off another time. Finally it stopped. No sooner had I got underway when I noticed oil shooting from a crack in the remote tank. I wadded a towel around the tank and was able to make it home. <br /><br />My questions are the following -- is the alarm related to the oil tank problem? And can I fix the tank by replacing it or should I enlist the help of a mechanic?<br /><br />Sorry for the long post. Any help for a new guy would be greatly appreciated. Thanks.

 

[aquamal]

Re: merc 150 remote oil tank/alarm - rookie question

A steady alarm i.e. Beeeeeeeeeeeeeep means that the engine is overheating, hence you turned off for a while and the buzzer stopped probably because the engine cooled enough to not trip the alarm. If you system makes a beep beep beep alarm then that is oil injection system.<br /><br />That said the oil injection system is pressurised by gas pumped from teh engine down into the remote tank which pushes oil up the pipe into the header tank at the top of the engine. If you have a leak such as your cracked tank then it is plausible that insufficient oil or no oil may be getting up into the header and therefore eventually down to the engine, therefore you mixture would be too lean and would burn hotter hence the overheat, and you may eventually cook your engine (ouch!). <br /><br />You definately need a new tank you cannot have cracks or gas escaping, and therefore pressure lost. Simply replace the tank the connectors are usually very straightforward although you should ensure connections are air tight, also try to fill the remote tank with 2 stroke oil (less area to pressurise) and definatley sure the header tank (on top of engine) is full of 2 stroke.<br /><br />Then try again - a top tip it is always handy to run the engine on premixed 50:1 fuel when you mess around with the oil injection just to make sure that you cant cook your engine.<br /><br />good luck...

 

[gss036]

Re: merc 150 remote oil tank/alarm - rookie question

You have 2 problems there. The oil tank under the seat does not have an alarm, the oil alarm which is a beep-beep-beep not steady beeeeeeeeeeeeep. Beeeeeeeeeeping contiously is an over heating alarm. Your are overheating. Find out why before you run anymore. When was the last time the water pump (impeller) was changed?<br />2. There should be a small oil tank under the cowling, make sure it has oil in it (full), that is where the oil alarm works from.There should be a float w/2 wires coming out of the tank cap, The float gets low in the tank and sets off the alarm.<br />The tank under the seat is pressurized by the engine and forces oil into the small tank under the cowling. Probable will need to replace the tank under the seat. Then check the tank to make sure it is not bulging, too much pressure. There are a couple of check valves in the lines (under the cowling). Find your overheating problem first.

 

[gss036]

Re: merc 150 remote oil tank/alarm - rookie question

Looks like Aquamal and I were posting replies at the same time saying the same thing. Good Luck.

 

[dcohan]

Re: merc 150 remote oil tank/alarm - rookie question

Thanks for the prompt replies. In case the previous owner doesn't know, is there a way to tell the age/fitness of my impeller? And is that something I can fix myself, or should I leave it to a pro? Thanks again.

 

[gss036]

Re: merc 150 remote oil tank/alarm - rookie question

How is the water flow in your pee hole? Good stream of water? That is the 1st thing to check. The lower end has to be taken off to change the impeller.