Merc V-150 Oil Injection Question

[Outrage 19]

Sorry for the new post but some of the old related posts are long and kind of ramble on so I started this one.<br /><br />Anyway down to business 1987 Mercury V-150 SN: 0B156087. I needed to rebuild because a sets of bent reed valves caused a lean condition in one cylinder and chewed up a piston. While at the machine shop inspection of the other cylinders showed a second cylinder needed boring in addition to the one with the bad piston. So I just received the two oversized pistons and now I’m ready to assemble.<br /><br />This is an oil-injected engine and since it has been working for the last 25 years I’m going to keep it that way. My question is does the oil injection system need to be primed and if so how? The Clymer manual I have doesn’t, or I haven’t found, a procedure to do this. Thanks in advance<br /><br />Outrage 19

 

[Kenny Bush]

Re: Merc V-150 Oil Injection Question

Yes you will need to bleed the motor tank(if it has one)by uncapping while the engine is running and watch it fill up. Once it hits the line, tighten oil tank cap. You can also manually fill the motor tank by hand. I would also put some in your gas tank so you will have double oil mix through break in.

 

[Outrage 19]

Re: Merc V-150 Oil Injection Question

Thanks BushCat I was planning to run double mix through the 5-hour brake in. Let me make sure I have the break in procedure correct.<br /><br />1 hour at idle<br />1 hour at ¼ throttle<br />1 hour at ½ throttle<br />1 hour at ¾ throttle<br />1 hour at WOT

 

[Kenny Bush]

Re: Merc V-150 Oil Injection Question

Man, I would not run that thing for 1 hour wide open. I have always broke my engines in by:<br />- double mix oil for the first 10 hours.<br />- do not run wide open until after breakin<br />- do not run over 4500 RPM's until after breakin.<br />- do not run the same RPM's for more than 10 minutes. Run 3800 for 10 minutes then 4200... then drop back to 3800. Just vary the RPM range while breaking in.<br />-after breakin, check/change plugs.

 

[Outrage 19]

Re: Merc V-150 Oil Injection Question

Ok guess I got that one all wrong. 10 hours it is. Thanks for setting me straight BushCat.

 

[Maximerc]

Re: Merc V-150 Oil Injection Question

Stready rpm for break in ? Never heard that one. I start mine for a couple of minutes, bring it just over idle a couple if times and shut it down. (you are letting the parts that are rubbing together too hard have a chance to cool) Restart and run it up and down to around 2200 for about ten min. Shut i down and let it cool. Biggest thing is no WOT for the first 10 hours. Also no pulling 400 pound skiers. Also NO syntetic 2 stroke oil until break in is compleat.

 

[Maximerc]

Re: Merc V-150 Oil Injection Question

Stready rpm for break in ? Never heard that one. I start mine for a couple of minutes, bring it just over idle a couple if times and shut it down. (you are letting the parts that are rubbing together too hard have a chance to cool) Restart and run it up and down to around 2200 for about ten min. Shut i down and let it cool.I just keep repeating this and taking the RPM up a bit each time. Biggest thing is no WOT for the first 10 hours. Also no pulling 400 pound skiers. Also NO syntetic 2 stroke oil until break in is compleat.

 

[ODDD1]

Re: Merc V-150 Oil Injection Question

If you are gonna keep the oil inj, [I would] acouple things to watch out for...back in this vintage, the oil seal liked to walk out of the back of the oil injection pump...check it, it should be below the bushing suface....also, look at the output check valve [ it is where the oil meets the fuel] it should take 2 psi of pressure to open and aloww oil into the fuel. With age they usually weaken and allow the oil to drain into the carbs when the engine isnt running, making smoky, hard starts.