1995 Merc 150 HP, carbed - Sea Trial

wilde1j

Vice Admiral
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Apr 15, 2002
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5,964
I'm going to sea trial a boat with twin 150's. Any issues to look for with these motors other than compression test, LU check for water. Any typical failure or weak areas needing careful inspection? Haven't owned or worked on larger Merc in years.<br /><br />What WOT throttle RPM to look for?<br /><br />Tkx for any meaningful feedback.
 

Kenny Bush

Chief Petty Officer
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Mar 24, 2002
Messages
564
Re: 1995 Merc 150 HP, carbed - Sea Trial

Only thing I would watch for is the water pressure guage. When you hammer down on these big mercs, if they do not cool efficiently, they will scour a piston quick... I have installed water pressure guages and on a couple of rigs I pulled the max timing back a couple of degrees to keep the pistons from scouring. Put some SeaFoam in the gas tank, and this stuff will clean the tank to the exhaust... Good luck....
 

bertad

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Nov 9, 2003
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Re: 1995 Merc 150 HP, carbed - Sea Trial

Hello wildeone,<br /><br />The engine should top out at 5200-5600 RPM at wot with full fuel and normal amount of people, equipment etc. If it doesn't the correct props are not installed.<br />Are the engines new or used? If used, look for old fuel and oil lines and replace as necessary.
 

rodbolt

Supreme Mariner
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Sep 1, 2003
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Re: 1995 Merc 150 HP, carbed - Sea Trial

hello<br /> luvtofish got it. look very close at the plastic oil lines. I tell my merc owning customers to replace the vynil oil lines every 3rd year. if you do odds are you will never do an overhaul due to a broken plastic line. its micky mouse but I dont design them I just fix them.<br /> good luck and keep posting
 

wilde1j

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Apr 15, 2002
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Re: 1995 Merc 150 HP, carbed - Sea Trial

Question for rodbolt: Is there an alternative material to the clear vinyl tubing for fuel/oil distribution that has a better service life? I spoke with a local Merc dealer service manager, who confirmed your comments. He said an overheat event almost always results in tubing failure, and the dealer just replaces with the std Merc pn tubing. Seems like there must be a better fix.
 

rodbolt

Supreme Mariner
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Sep 1, 2003
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20,066
Re: 1995 Merc 150 HP, carbed - Sea Trial

Hello<br /> not that I will go out on a limb about. although there are some motors out there that now have nice rubber fuel line tubing now. but the vinyl will work just replace it every 3 years
 
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