Mercury 850 85hp. Good engine or stay away?

Bman2895

Petty Officer 2nd Class
Joined
Feb 11, 2016
Messages
165
I run up a shallow arm of my lake and have not had that problem but i do not put on the tab.

When kicking over in the driveway before every trip, i do have to lower and prime. Raised to tabs and primed does not work.

82 model.
Oh I wasn't running it while up on the tabs. I'd kill it floating up to the bank go back pull the motor up put it on the tabs and then Coast it into the sand
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,808
Those motors when tilted, leaked fuel out of the carb throats. The fuel sat in the lower cowling fuel drain "pan" until the motor was tilted down and then leaked into the water. Most of the time, you needed to reprime.

The PTT system on the 50HP motor is a bit different than the one original to the 850. I do not think they will interchange. The PTT system on the 115HP motor should work on the 850.

I would look into aftermarket PTT systems for that motor, as the original PTT systems took up space in the boat, the cylinders often leaked and repair kits were either not avail and if avail, were tricky to install without a special tool. Also, replacement PTT motors were hard to get. ARCO used to make them, but not sure if they still do.
 

Texasmark

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Joined
Dec 20, 2005
Messages
14,988
The brown / copper decals were for 84 / 85 models.
Mine had Mercury spelled with a "lower case" m.......disqusted me every time I looked at it.......It had 3 stripes, silver, red, and one other color, blue I think, I forget.....they were beneath the name in a straight line from the front of the cowl straight back and at the rear turned down and cut off.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,988
Those motors when tilted, leaked fuel out of the carb throats. The fuel sat in the lower cowling fuel drain "pan" until the motor was tilted down and then leaked into the water. Most of the time, you needed to reprime.

The PTT system on the 50HP motor is a bit different than the one original to the 850. I do not think they will interchange. The PTT system on the 115HP motor should work on the 850.

I would look into aftermarket PTT systems for that motor, as the original PTT systems took up space in the boat, the cylinders often leaked and repair kits were either not avail and if avail, were tricky to install without a special tool. Also, replacement PTT motors were hard to get. ARCO used to make them, but not sure if they still do.
Opinion: I think the 115 was just the 850 with an extra carb and a couple more pistons stacked on top.....with a 2:1 gear box. Having had both, The '88 115 I6 was liken to a well oiled sewing machine. Another mighty fine engine that loved to run my little Ranger "pad" boat at 50 MPH at 6k RPM. You could hear the engine singing and the prop humming since the blade tips were right at the surface at best trim....Mercury original Laser SS prop.
 

redneck joe

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Mar 18, 2009
Messages
15,159
Ive looked for an aftermarket tnt system but havent found one that can handle a motor larger than 35 or so?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,808
Mark, the 115HP IL6 was indeed an 850 with another carb and two more cylinders, labrinth seal and reed valves. The Mercs were modular in that way.

CMC used to make PTT systems for larger HP motors. They may not be the only ones.
 
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