1972 Merc 1400

[linckeil]

Re: 1972 Merc 1400

Find the number on the carbs

the motor is at my parent's place. maybe i'll get over there tommorow, but at the latest by the weekend. at least its getting narrowed down a bit....

 

[ricksrster]

Re: 1972 Merc 1400

In picture 5 it looks like the choke plunger is out of the choke solenoid.

 

[linckeil]

Re: 1972 Merc 1400

In picture 5 it looks like the choke plunger is out of the choke solenoid.

it is. the rear cover where the electronics bolt to is broke in half and the wire on the plunger is tied to that plate and was pulled out when the plate broke. so all it needs is a starter, throttle lever, and rear plate - all of which i luckily have.

 

[Chris1956]

Re: 1972 Merc 1400

Linc, Look on the block for the part number. Then go to www.dougrussell.com and look up the 140HP by serial number and match 'em up. Since that motor was built, any powerhead could have been put on.

You migt pull a transfer cover and see if the piston has three rings (Original) or two rings (newer) and whether the piston has the power port.

 

[linckeil]

Re: 1972 Merc 1400

i just tried the dougrussel site and entered the block number i mention earlier in the thread (4320181) and nothing comes up. i tried searching for it in all fields. maybe i am using the site wrong?

anyway, i got some numbers off the carbs today. all 3 carbs have the same numbers on them, but i couldn't find anything begining with "WMK". the top of the bowl were the fuel enters reads "1399-1930 MERCARB". just below that were the fuel inlet meets the bowl it reads "1399-4664 MERCARB". and on the bottom of the bowl it reads "1399-3682 MERCARB" and it says "1 1/4" in a circle. does any of this help identify my powerhead?

i checked the compression today too. with all 6 plugs out, the throttle held wide open, and 2 squirts of ATF in each cylinder, all cylinders were between 120-125 psi. i expect it to read about 115 psi once the oil burns out. so i'm very happy with those readings.

 

[Chris1956]

Re: 1972 Merc 1400

Linc, On the Doug Russell Site, click on "Browse parts"; "Mercury"; "Model" 1400: your Serial number range; "Cylinder block and end caps". Scroll down to the block part number and match the block number (not serial number) found on the transfer port side of the block(??), with the part numbers. You may have to match by serial group as well

 

[linckeil]

Re: 1972 Merc 1400

I found the WMK# on the carbs. It is on the side of the bowl and was hidden by the choke mechanism...

anyway, the bottom 2 carbs say WMK 9. the top carb says WMK 9-1.

still trying to identify this powerhead.

 

[Droll]

Re: 1972 Merc 1400

I found the WMK# on the carbs. It is on the side of the bowl and was hidden by the choke mechanism...

anyway, the bottom 2 carbs say WMK 9. the top carb says WMK 9-1.

still trying to identify this powerhead.

WMK-9 were used on the late 1972 Merc1400.

My silver painted ( powerhead )1400 got WMK-7 carbs.



Arne Kjetil

 

[linckeil]

Re: 1972 Merc 1400

so is that the only motor the WMK-9's were used on? does this mean that if the carbs are original, the powerhead is in fact a 1972 1400?

 

[Droll]

Re: 1972 Merc 1400

so is that the only motor the WMK-9's were used on? does this mean that if the carbs are original, the powerhead is in fact a 1972 1400?

Yes.


Arne Kjetil

 

[linckeil]

Re: 1972 Merc 1400

interesting.... it seems everything from carbs to electronics indicates the motor to be a 1972 1400, but the powerhead serial number is still throwing me off....

are the WMK9's good carbs? were they an upgrade to the WMK7's?

 

[Droll]

Re: 1972 Merc 1400

but the powerhead serial number is still throwing me off....

how ??
1400 (140,0) 3293234 - 4865677 = 1972 and you got 4320181

are the WMK9's good carbs? were they an upgrade to the WMK7's?

SERIAL #3295134 AND up used WMK-9 carbs ( #1352-4510A21 )
The only difference I could find was the main jets.

• WMK-7 used .084 ontop, .082 on mid/bottom
• WMK-9 used .080 on all carbs .

There were also a service bulletin on the jet size on the 1400 (73-3 D ), don't know what it was ?? .

Arne Kjetil

 

[linckeil]

Re: 1972 Merc 1400

how ??
1400 (140,0) 3293234 - 4865677 = 1972 and you got 4320181

where did you find that range? as i said earlier, oldmercs.com says a 72 1400 serial number is 3293234 thru 3502805 - in which my riveted serial number plate falls into the range of.

but my powerhead at 4320181 is either a 1976 1150 or a 1976 1500 (among other options, but these 2 are the most likely as other options are inline 4's and smaller, and V6's) per oldmercs.com

if there's another source for serial numbers i'd love to see it as oldmercs.com has a lot of discrepancies amongst serial numbers.

what are the odds my motor came from the factory with a mismatched powerhead and riveted plate serial number? the motor looks so original, unused, and untouched that its hard to believe the powerhead was swapped....

 

[Droll]

Re: 1972 Merc 1400

where did you find that range? as i said earlier, oldmercs.com says a 72 1400 serial number is 3293234 thru 3502805 - in which my riveted serial number plate falls into the range of.

Mercury serial/year numbers are, kind a confusing

I usually uses this site, but you can find other sources too, like this one, or this one.......

But.... did you find any other numbers on the block, anything like 4880 ??, on old Mercurys, some of the parts casting number can be used as part number, not always, but sometimes ..


Arne Kjetil

 

[linckeil]

Re: 1972 Merc 1400

ok, checked all over the block for numbers...
aside from the serial number i mentioned (4320181), i found a few others. all are on the side opposite the distributor (starboard side)

directly above the serial number: "852-5591"

directly below the upper fuel pump: "62978"

directly above the upper fuel pump: "62301"

there was a number on the cylinder head too. in the #2 cylinder bank below the #2 plug: "1023 5068"

thats all the numbers i've found. does this help at all?

 

[Clams Canino]

Re: 1972 Merc 1400

That's not a head... it's a water jacket cover.

The 1972 1400 is kinda a one off critter. It's like the 1350 with the new exhaust exits, or like a 1500 missing the boost ports. It's the "missing link".

Great inline though.... use .080 mains, 21 degrees max advance, and mid-grade gas.

-W

 

[linckeil]

Re: 1972 Merc 1400

thanks to all who have helped me through this. i'm learning a lot about these motors thanks to you guys.

i have a question about the wiring on this motor. i found a wiring diagram that a member posted here in another thread. In comparing that diagram to the existing wiring on my motor, there is one discrepancy i've found. one wire is hooked up to a different post than what is indicated in the diagram. i think maybe the prior owner disconnected the line and incorrectly hooked it back up to the wrong post.

take a look at this picture. this is how the wiring is currently hooked up:

http://profile.imageshack.us/user/linckeil/images/detail/#172/721400ph1tm8.jpg

you can see in the picture that the brown terminal on the switchbox (2nd post from the top) has no wire going to it. then look below the switchbox at the rectifier. the bottom yellow post has 2 wires runing to it. per the diagram, the brown post on the switchbox should have a brown wire running to it and the bottom post on the rectifier should have only 1 wire running to it - not 2. the second wire on the rectifier post is indeed brown leading me to believe that this brown wire should be run to the brown post on the switchbox. i think the answer is obvoius that my assumptions are correct, but i wanted to be sure before i rebuild the harness and try to fire it up.

so please take a look at the picture and let me know what you guys think. thanks again.

 

[Droll]

Re: 1972 Merc 1400

You are right about the brown wire are on the wrong place according to the schematics, but it will not be any problem.

The brown wire goes to the tack, back then the switch box got a tack outlet ( special tack for the Thunderbolt ignition ), later tacks used the AC output from the stator ( one of the yellow wires, on the rectifier )

If you got a old tack designed to work with the Thunderbolt system, move the brown wire to the switch box.
If you got a later tack (Faria, Vdo, Teleflex, ++++ ), leave the brown wire on the rectifier, set the tack on 12 pulses.



Arne Kjetil

 

[ricksrster]

Re: 1972 Merc 1400

12 pole/6 pulses

 

[linckeil]

Re: 1972 Merc 1400

got ya. thanks, so it appears the engine was once on a boat with an aftermarket tach not compatable with the thunderbolt ignition.

the engine will be replacing a 1973 850 that has all stock mercury gauges, so i will move that wire.

and this leads me to another question... will the tach that works with the 4 cylinder 850 work with a 6 cylinder? i know some automotive tachs have a switch on the backside that will allow you to go from 4,6, or 8 cylinders. i need to check if the tach on my boat maybe has a switch on it.