Mercury 850 85HP Trim Problem

[bassloverky]

Does anyone know the oil ration for an 850 85HP motor. I think it is an 80s era motor. Just bought the boat and the previous owner didn't use the boat and has no idea.

I am also having a trim problem. I was told by a repair shop that the trim was probably added to the boat. This is my first boat that used a gas motor. From what I can tell the trim motor is working (whining) but it may be low on fluid. It trims down but wont trim back up. Unfortunately I have no idea how to check the fluid level. I have located the trim pump/motor but can't find any place to check the fluid level. I realize more information is probably needed but I don't know were to get it.

Also if anyone can tell me the year and any other info on my motor I would appreciate it.
Serial # 451193

Thanks in advance

 

[Plainsman]

Re: Mercury 850 85HP Trim Problem / Year info/ Oil Ratio

Re: Mercury 850 85HP Trim Problem / Year info/ Oil Ratio

Welcome to iboats!!
Motor is a 1976
Fuel ratio is 50:1
Look for a straight slot screw on the trim motor, that will be the fill. You can use ATF or something like 20 w oil in it. I do not know the proceedure for bleeding the system, but you can do a search for bleeding tilt/trim.

 

[bassloverky]

Re: Mercury 850 85HP Trim Problem

Thanks! Sorry about the duplicate post for the year question.

 

[Plainsman]

Re: Mercury 850 85HP Trim Problem

 

[Smig]

Re: Mercury 850 85HP Trim Problem

Here are copies of the Installation and Owners Manuals for the older two-ram trim units. These may answer a few of your questions.

Smig

 

[bassloverky]

Re: Mercury 850 85HP Trim Problem

Thanks! I love this forum. I would be lost without this info.

Any recommendations for a service manual for my 1976 Mercury 850 85HP? I should probably pick one up. It might save me some money down the road.

 

[Smig]

Re: Mercury 850 85HP Trim Problem

Any recommendations for a service manual for my 1976 Mercury 850 85HP?

I would recommend the factory manual and an aftermarket one - the factory for just about everything, but the aftermarket for some simple directions.

oldmercs.com and maxrules.com are two places that sell the factory manual. I found both of mine on ebay...

Smig

 

[bassloverky]

Re: Mercury 850 85HP Trim Problem

Thanks to everyone for your help with the trim problem. I was able to figure out what everything was on my trim motor by using the PTT manual. It was low on oil and I added SAE10W30 following the manuals instructions. The trim works great now!!!