No spark, 120 mercruiser

[BMK10]

Hey guys so I've been trying to get a 120 mercruiser started thats been sitting for several years. I got the engine cranking but won't start. Pretty sure I have a fuel pump issue because the carb is dry however I've been spraying starter fluid into it and still get nothing so I'm assuming I have no spark as well.
I tested the coil from + to ground which read 11.9v, then I tested the lead out to ground which read 11.9v. Then - to ground which also read 11.9v.
I sanded the points a little considering its been sitting for so long, However I noticed there is quite a large gap in between the points so I'm wondering if they are my problem.
I have a good running 3.0l engine on another parts boat and I'm wondering If I can just swap the cap, points and all into the 120 that way I can avoid adjusting the current set up. It looks like everything just unscrews. Any opinions on this?
Thanks
Brad

 

[achris]

First opinion. Throw away the starter fluid. .. does more harm than good.

It does sound like the points may be the problem. I would turn the engine until the points are open, then with a spark plug connected to the coil HT lead, touch a wire between coil- and ground, rapidly a few times. That should generate sparks. If it does, try it cranking the engine. If that also sparks your problem is cap or rotor. If not, it could be the points.

 

[BMK10]

hmm okay just to make sure I'm following ya... You're saying connect a spark plug to the lead that connects the coil and distributor.. then hookup to the spark plug with a wire and ground it rapidly?
Sorry electrical stuff isn't my best subject.
Also out of curiosity why no starting fluid? does it lead to corrosion or something?

 

[achris]

Starter fluid is basically ether. It'll blow head gaskets.

Pull the HT lead out of the centre of the distributor cap. Put a spark plug in the end and lay it on the engine block. Turn the engine till the points are open. Take a normal piece of wire and connect it to the negative of the coil. With the key ON, tap the other end of that wire on a good ground. . Should get sparks across the spark plug.

 

[BMK10]

Okay thanks I will update in the morning

 

[Scott Danforth]

file your points, reset your points. if points sit longer than a few months, a bit of corrosion coats the contacts.

 

[BMK10]

Okay so so I'm getting spark. tested with the key on and while turning over, sparked both times. So I'm assuming the problem is the points?

 

[achris]

If you're getting spark, the points are fine. If you have spark at the coil but not at the spark plugs, the problem is the cap or rotor. (Or the leads. )

Chris. ..

 

[BMK10]

file your points, reset your points. if points sit longer than a few months, a bit of corrosion coats the contacts.

I have tried sanding them a little bit however I'm still getting nothing. I can see the points opening and closing when the engine turns over but maybe they need to be reset? I'm not too experienced with checking the dwell and what not which is why I was wondering if I could just swap my cap and points from my 3.0l?

 

[BMK10]

Ok disregard that last post. I filed the points some more and checked the gap which was about .020" ..So I hooked everything back up, put a little gas in the carb and she fired, well for a split second. Gonna swap the fuel pump out and hopefully it'll fire up cause right now the carb is dry. Maybe I didn't sand the points enough the first time.
Thanks guys.

 

[Scott Danforth]

you need to get a dwell meter to properly set the points.

 

[hogbare35]

Get a kit for dist. and do away with the points set up. I think the electronic set up is the way to go.

 

[BMK10]

you need to get a dwell meter to properly set the points.

I just found one online that I'm going to order. Seems like a good tool to have. However now I'm having trouble swapping my pumps. I was planning on using the pump from my 3.0l since its only a year old. However it looks like they are different pumps, one is mounted upright and the other is upside down. Also it looks like the actuator arms are set at different angles, I don't want to bolt this one up and mess up the cam or something. I figured the pumps would have been the same..
Is there a way to rebuild fuel pumps or am I better off just buying a new 120 pump? I'm getting fuel in the line to the pump however nothing from the pump to the carb so that's gotta be my problem right?

 

[BMK10]

Get a kit for dist. and do away with the points set up. I think the electronic set up is the way to go.

I would do a swap but I bought this as a project boat to get running and then sell so I'm trying to spend as little as possible. I do agree with you though.

 

[Scott Danforth]

the 3.0 most likely has the newer pump on it.

you can borrow a dwell meter from your local auto parts store.