Removing an 85 HP

[SkaterRace]

I have a 1977 Mercury 850 with power trim on it, I need to remove it to do fiberglass repairs to my boat. I am not sure how to do it the most simple way. I would like to not have to drain the power trim unit if possible. Looking at it I see lots of bolts holding everything together and am not sure where to start removing. I think I can take the rams off by themselves but not 100% on it.

Will post pictures of it later when I get the chance.

 

[Texasmark]

I think you have asked several questions about this engine and I answered at least one. It's been a long time but the engine is intact in that you unbolt the transom bracket from the transom (4 bolts) and it's ready to lift (mechanically, not manually) off. That engine weighs over 200# for a number. The pump as I recall is located elsewhere and you might just disconnect the wiring and remove it and the reservoir with the engine as one unit.

Or you might mark your hoses to ensure you get them back to the right place at the cylinders, removing them there and lift the engine off leaving the rest in the boat. Let the engine all the way down before you start and prop the hoses up vertically. When you put it back together, run the trim up and down till you get the air bubbles out of it, replacing any fluid you lost in the process....fluid type is ATF if red, or Quicksilver/Merc PTT fluid if clear.....so says the manual.

Best way to lift the engine is with the crankshaft threads protruding out from the center of the flywheel. Make an adapter or ebay usually has one. Sometimes you have to remove the flywheel nut to have enough threads to grasp.

 

[SkaterRace]

I think you have asked several questions about this engine and I answered at least one. It's been a long time but the engine is intact in that you unbolt the transom bracket from the transom (4 bolts) and it's ready to lift (mechanically, not manually) off. That engine weighs over 200# for a number. The pump as I recall is located elsewhere and you might just disconnect the wiring and remove it and the reservoir with the engine as one unit.

Or you might mark your hoses to ensure you get them back to the right place at the cylinders, removing them there and lift the engine off leaving the rest in the boat. Let the engine all the way down before you start and prop the hoses up vertically. When you put it back together, run the trim up and down till you get the air bubbles out of it, replacing any fluid you lost in the process....fluid type is ATF if red, or Quicksilver/Merc PTT fluid if clear.....so says the manual.

Best way to lift the engine is with the crankshaft threads protruding out from the center of the flywheel. Make an adapter or ebay usually has one. Sometimes you have to remove the flywheel nut to have enough threads to grasp.

Thanks and you are right I have asked a few questions but mostly regarding repairing it and "upgrading" it with filters for the intake (never did figure this one out). Motor has bad valves and piston seal on #3. Fixed it with help from the forum well I think anyways have yet to test it since I don't feel safe doing it with the transom damage.

 

[Chris1956]

If the PTT hoses pass thru the hull, you will need to disconnect them at the PTT pump. The connection of the PTT hoses to the cylinders can strip out easily, and I do not know of a fix, except replacement of the cylinder.. Put a plastic bag over the PTT hoses to keep the dirt out of them.

 

[Texasmark]

If the PTT hoses pass thru the hull, you will need to disconnect them at the PTT pump. The connection of the PTT hoses to the cylinders can strip out easily, and I do not know of a fix, except replacement of the cylinder.. Put a plastic bag over the PTT hoses to keep the dirt out of them.

Chris,

I had one of those 850's; mid 70's or thereabouts.....decal on engine were 3 stripes, silver, red, lt. blue and at the aft end of the engine they went south, like Ranger boat's logo. Also, Mercury on the engine was spelled mercury.

The PTT cylinders were just replacements of the shocks that used to occupy that position in earler models of mercs. I had it on a bass boat which was narrow and had a side depth of about 24"...just barely above the 20" transom. I do not recall any plumbing through the transom other than the drain plug. Butttt it's been a lot of years and a lotta boats since.

 

[Chris1956]

Mark, Your motor's decals sounds like a '76/77. If so, the PTT used brackets on the top of the transom to secure the tops of the PTT cylinders. The PTT cylinders were longer than the shocks on non-PTT motors. The PTT hoses would have gone into the boat to connect tot he external PTT pump.

 

[CV16]

When I pulled my motor off I just disconnected the rams and let them hang. I then lifted the motor off. That was the least messy way I could think of.

 

[Texasmark]

You got-r-done. That's what matters.

Thanks Chris. Been a long time since the mid 70's. Grin

 

[444]

I took the 1978 175hp mercury off my boat. I strapped the engine to my cherry picker, unbolted everything and pulled it out of the way. Mine has the power trim fluid that goes through the transom bolts. Disconnect your lines and wrap rags and bags around the connections. The mess is actually minor. Best is to get everything removed out of the way so you can do your repairs and reseal everything after with some marine silicone.

 

[SkaterRace]

Update: I have removed the engine, I had to disconnect the PTT lines from the PT pump then remove then through the splash well. Next I hooked it up to a chain fall and lifted slightly. I then removed the bolts and loosened the clamps then lifted till it was off. Not standing too safe right now but am taking a break and will support it after a water and a beer. Thanks everyone!