1977 Mercury 850 85hp firing order

[boating85hp]

Hello All,

I'm a new member to the board and just purchased my first boat and having issues already. Could someone please let me know what is the firing order of the spark plugs. Right the spark plug wires is connected as follows: 1 2 4 3. Is this correct?

Thank you,
D

 

[chum1]

Re: 1977 Mercury 850 85hp firing order

normally the wires are connected in descending order just as labeled 1234 with #1 being on top

 

[Chris1956]

Re: 1977 Mercury 850 85hp firing order

A '77 850 should have the four coils. Connect the coils top to bottom to the closest cylinder. The wires from the switchbox to the coils provide the firing order.

 

[boating85hp]

Re: 1977 Mercury 850 85hp firing order

I made an error with the year. It is a Canadian made Merc. 850 serial # 7063553 which is equvilent to US 4590511. So it is a 1976 not 77.

The plug wires from the Distr. goes to the plugs as follows: 1 2 4 3. Should I switch it to 1 2 3 4? I bought the boat this way

Thank again!
d

 

[Chris1956]

Re: 1977 Mercury 850 85hp firing order

The distributor cap should have markings on it for the cylinders. I think the firing order was something like 1,3,4,2. You can check it using a screwdriver thru the spark plug holes.

 

[merc850]

Re: 1977 Mercury 850 85hp firing order

The order is on the block near the plugs and it is 1-3-2-4.

 

[boating85hp]

Re: 1977 Mercury 850 85hp firing order

The order is on the block near the plugs and it is 1-3-2-4.

Thank you....all good now...just need to deal with a sticking starter now
D