1960’s mercruiser 120 help needed

[vscrl1]

I recently acquired a 1960’s aristocraft nineteen and the lower unit was off and engine cranked but wouldn’t fire. From what I could find from wiring diagrams from the mercruiser manual posted online, it looks like the coil isn’t wired right? Can someone verify this? Brown wire is on positive, black wire to negative and white wire isn’t connected. I believe white is positive, and brown is negative and the black is negative from the distributor? Also the exhaust elbow is missing all of its bolts. Anyone know what size bolt it takes or where I can order them? Needs the gasket too. Thanks in advance everyone

 

[achris]

Hello vscrl1 and :welcome: aboard.

We'll need quite a bit more information than '1960s 120'. Merc ran the 120 from 1964 to 1989, and in the 60's there were a lot of changes, especially to the exhaust and cooling systems. The best thing would be to post an engine serial number. It will be a 7 digit number.

As far as the wiring, the white is power which does go to the coil plus, and both the black and brown go to coil minus. The black goes to the points in the distributor and the brown runs back up the instrument harness and is the tacho signal.

As for the gaskets and screws, we would need to know which particular manifold and elbow you have.

Chris.......

 

[vscrl1]

Ok ill see if i can find a serial number. I tried posting pics but it didnt work

 

[vscrl1]

The only number i found was 21030, but im not sure thats the serial number as 221030 is stamped in the metal trim by the dash

 

[Bt Doctur]

just so or aware parts for those drives are no longer available

 

[vscrl1]

Part for the drive or the engine?

 

[achris]

Part for the drive or the engine?

both

 

[vscrl1]

Great lol. Just checked the oil (yep forgot to do it when i looked at the boat) and it has water in it. So basically theres no to replace gaskets or anything on this boat? So its basically garbage then right?

 

[Scott Danforth]

first, your motor has points.....

did you file them? if not, do so. all points need to be filed, even new points

then gap them to .018", verify the dwell at 28 to 32 degrees, and then set timing

if you need to replace, get a 1992 or newer 3.0 / alpha 1 gen 2 and swap in.

 

[vscrl1]

I dont have a clue with points and gapping or anything. Sorry. But the carb wasnt getting fuel so guessing that the fuel pump is bad. Disconnected the line at the carb and turned it over and nothing came out. No blockages in the lines either. Tank had 5 gallons in it. Currently trying to pull the headgasket. Pulled intake and there was a little rust on the intake side of cylinder 4. Lots of rust on all exhaust ports. Not having any luck getting the head bolts loose. Also do i need to remove the valve springs in order to get the head off? Im pretty sure i do but thought id ask. Also a local marina told me they could gaskets for this but the guy argued with me about the serial number i gave him (21030) which is the only number on a plate by motor. He said it absolutely should be a 7 digit number. Any ideas on that one? Wish i could upload pics but it keeps saying file size is too big

 

[achris]

If the file size is too big, reduce it. Plenty of software or there to do that. Or if you are using a phone, reduce the picture size of what you're taking, or upload the pictures to a photo sure and post the link here.

Absolutely right, the serial number will be 7 digits. There's a plate (or should be) on the engine block, just above the start motor. Serial number will be on that...

Have a look in the MerCruiser stickies. I posted a thread on where to look for serial numbers...

Chris...

 

[vscrl1]

Yeah i found it. It is missing part of it. It looks like someone pulled the outdrive and engine apart at one point. Part of the plate is now bent and smashed in between the engine and outdrive. It reads "rial number" and under that "12030." I did find all of the gaskets i need but the fuel pump is no longer available and the bolts for the exhaust elbow are also no longer available. So looks like ill be taking the intake to the hardware store to find bolts. Anyone know about how long the bolts need to be? Still no luck getting the head bolts off either. Soaking them in PB blaster overnight. Figured i have everything else off, might as well check the head gasket out too although im really thinking the water in the oil has something to do with the intake. Intake passages are rusty and the exhaust ones are not. Would the gas really make them that rusty? I would think only water would do that.

 

[vscrl1]

Based on the parts on my boat, listed by crowleymarine.com, my serial number is somewhere in this group. Im missing the first 2 digits. I was able to identify it by the intake manifold setup that i have. 2046625-2324346. Those serial numbers are from somewhere between '65 and '72

 

[Scott Danforth]

My recommendation..... Since you clearly dont know anything about internal combustion motors..... Your two choices are to either learn (suggest taking some classes in auto mechanics) or pay someone.

All the gaskets are still available. Direct from GM, Reinz, Mahle and others..... Same gaskets as a Chevy 153 in a nova, other than the head gasket.

No, you dont pull the valve springs untill you have the head off.....

You need to understand points with your motor. There is a guide in the stickies.

 

[vscrl1]

I was told the head gasket was the only thing thats the same as the nova. That came straight from a mercruiser tech. Any idea on the exhaust elbow bolts? And ill read up on points after i figure out why i have water in the oil

 

[Scott Danforth]

Most likely your exhaust manifold is leaking.

Pull the exhaust and if you see rust in the exhaust ports, your exhaust elbow gasket ot the manifold is leaking, and that is a potential source of water in the oil.

Do a cooling system pressure test, if the block doesnt hold 15psi, could be a casualty of improper winterization

 

[achris]

I was told the head gasket was the only thing thats the same as the nova. That came straight from a mercruiser tech. Any idea on the exhaust elbow bolts? And ill read up on points after i figure out why i have water in the oil

Then find another mechanic, because that one clearly knows nothing. The head gasket, core plugs and water pump are marine specific. The electrical and fuel systems are marine rated, and all other engine part are either GM or other suppliers to Merc. The only thing 'Merc' on the engine is the manifold, and for that serial number group, most of the parts are NLA.

2046625-2324346. Those serial numbers are from somewhere between '65 and '72

That serial number group is 1967.

Chris.....

 

[vscrl1]

I pulled the manifold and have rust in the intake ports. Exhaust ports are clean. The elbow however has lots of rust. The fuel pump is also no longer
available for my boat. can someone tell me a suitable replacement? Thanks for the help everyone

 

[achris]

I pulled the manifold and have rust in the intake ports. Exhaust ports are clean. The elbow however has lots of rust. The fuel pump is also no longer
available for my boat. can someone tell me a suitable replacement? Thanks for the help everyone

I'd be making sure everything else is working properly before pouring ANY money into a 53 year old engine and drive that parts are NLA for.

Get a 20 litre fuel container and set it up (securely) above the carburetor, then just let gravity be the fuel pump to get the engine running... Then you will know if you have something viable or not.

Chris.....

 

[vscrl1]

I already took off the manifold. Plus i need to change the oil. There was literally water and white vaseline like crap in the top of the rockers. I poured gas into the carb before i took the intake off and it was trying to start. Im gonna get some new plugs n wires and feeler gauge for the points and make sure everything is at tdc. The intake gasket looked fairly new. Im thinking someone changed it without cleaning the mating surfaces. So ill try reusing it for the sake of getting it running. As far as the lower unit goes, the impeller is missing the water tube that sits on top of it. Will other ones fit it or is the lower unit junk now?