Newbie to Mercury outboard 85 Hp

[Mercury850]

I just got an outboard advertised on e-bay as 1977 model 85 Hp Mercury outboard. When I received it yesterday, I looked up the serial number #4301232 on the name tag. Then I saw other serial number on the engine block #3496798. The motor has a blue metal band cover in the middle. It has an external tilt/trim pump and the pump is real bigger than typical pump I have seen on other outboard. It has a distributor driven by a belt. So what is my motor year ??? Which serial number do I use to order parts ???
The e-bay owner told me it was running outboard but it needed a lower unit because its lower unit could not go to reverse. I did compression test to day: Cylinder #1,#2,#3 and #4 as followings:
First trial: 138 psi, 134 psi, 145 psi & 132 psi
Second trial: 140 psi, 140 psi, 141 psi & 140 psi
Third trial: 140 psi, 140 psi, 140 psi & 135 psi

Do I have to tear it apart to rebuild ?
All electrical wires are bad. I will redo all the wires.
Is it good and reliable motor ?
Thanks,

 

[Chris1956]

Re: Newbie to Mercury outboard 85 Hp

The compression is good. The wires likey need replacing. Try Surplusunlimited.com for them. Clean the carbs and rebuild them. Inspect the floats and replace any that are cracked or deteriorating. Perform the link and synch.

That motor is likely between 1971-1976. The 850 was not made every year. If you get on the Crowleymarine.com web site, you can look up parts for it. I think the inline 4 motors had distributor ignition until 1976 or so, but I am really not sure.

 

[egclassic]

Re: Newbie to Mercury outboard 85 Hp

http://www.maxrules.com/Merc_model_files/60-100.html

Copy and paste the above link, should help.

 

[monk-monk]

Re: Newbie to Mercury outboard 85 Hp

My references says thats a 1973 model...any repairs to the powerhead and components should be purchased using the serial number off the powerhead itself.

 

[Mercury850]

Re: Newbie to Mercury outboard 85 Hp

So I got screwed. It is not 1977 model as advertised but it is 1973. Look up Crowleymarine.com web site, 1973-1977 models were all most the same. They had almost the same components.

 

[douglas1978]

Re: Newbie to Mercury outboard 85 Hp

if it is the motor i saw on ebay http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=260592951183&viewitem=&sspagename=STRK%3AMEWAX%3AIT then alot of things need to be checked and replace 12 years is alot of sitting

 

[Wingedwheel]

Re: Newbie to Mercury outboard 85 Hp

I have the same engine and when I bought it I had some of the same problems. I rebuilt the carbs and fuel pump, fabricated new fuel lines(which are NLA) and had the shifting problem going into reverse. the shifting problem ended up being a worn-out shaft coupler. The lower units are very easy to work on and diagnose. The engine overall has been very easy to work on and it has been a very reliable motor since I got all the little things taken care of that were caused by total neglect over the years from the previous owners. As long as you have good compression, fuel and spark, you will enjoy that outboard.

 

[egclassic]

Re: Newbie to Mercury outboard 85 Hp

So I got screwed. It is not 1977 model as advertised but it is 1973. Look up Crowleymarine.com web site, 1973-1977 models were all most the same. They had almost the same components.

Yes, except there are two different cam shift types on the lower units, and quite a few parts are different. Mine is a Type 1 and iboats only shows the break down for the type 2, at least from what I could find.