1990 Mercruiser 4.3 LX/V6 Alpha One Cranks But won’t Start

[ChrisC631]

Hello everyone, first time poster here. I purchased a 1990 Sea Ray 200 off of craigslist as a project. I've rebuilt the carburetor (rochester quadrajet), replaced 2 batteries, replaced the spark plug wires and cleaned wire connectors all around the the motor and battery area.

The motor cranks but does not turn over. I am not using the gas inside the boats fuel tank as i believe it may be contaminated with water (gentleman let the boat sit for 2 years covered). Currently using an external gas tank.

i do not have the serial number at the moment but i will in a few hrs or so.

Any and all help would be much appreciated. Thanks guys!

 

[alldodge]

The motor cranks but does not turn over.

For most of us this means the same thing, cranking and turning over. Do I take it this means it will crank (turn over) but it will not run?

If the above is true then need a volt meter to see if you have 12V on the + side of the coil?
What does the distributor and rotor look like and have they been replaced?
Are you getting spark?

 

[ChrisC631]

For most of us this means the same thing, cranking and turning over. Do I take it this means it will crank (turn over) but it will not run?

If the above is true then need a volt meter to see if you have 12V on the + side of the coil?
What does the distributor and rotor look like and have they been replaced?
Are you getting spark?

My apologies, the motor turns over but does not start/run. The distributor according to the seller was replaced 2 years ago. I just got spark plugs as he told me they should be replaced but were fairly "new"

 

[alldodge]

Pull the distributor cap and have a look under it to see what the contacts look like.
If you can get a hold of a timing light, put it on the coil wire when cranking to see if it flashes

 

[JASinIL2006]

Also, if your boat has a kill switch (often, there is a lanyard attached that activates the switch if you fall out of the boat), make sure it's not flipped. That also will allow the boat to crank without starting.

 

[ChrisC631]

Engine serial number: 0C858047

I checked the Distributor besides one of them that looked a little dirty they were fine. I found a 7? Point connector by the ignition that wasn’t pushed in all the way.

I took a spark plug out and it it looked a little worn. Will replace and update.

As for a kill switch, I did not find one.

 

[H20Rat]

Engine serial number: 0C858047

I checked the Distributor besides one of them that looked a little dirty they were fine. I found a 7? Point connector by the ignition that wasn’t pushed in all the way.

I took a spark plug out and it it looked a little worn. Will replace and update.

As for a kill switch, I did not find one.

On the control console, possibly on the lower front side by your throttle. Sometimes they aren't easily visible.

 

[ChrisC631]

On the control console, possibly on the lower front side by your throttle. Sometimes they aren't easily visible.

the previous owner stated there was not a kill switch installed.

 

[alldodge]

the previous owner stated there was not a kill switch installed.

Being a 1990, look at the wiring on the key switch. There are 3, Red/Purple, Yellow/Red and Purple.
Follow the purple to see if if goes straight to the gauges or goes toward the shift.

Now if you turn the key to ON/RUN and the gauges turn on, then don't bother looking

And still need to do this

need a volt meter to see if you have 12V on the + side of the coil?

 

[ChrisC631]

Being a 1990, look at the wiring on the key switch. There are 3, Red/Purple, Yellow/Red and Purple.
Follow the purple to see if if goes straight to the gauges or goes toward the shift.

Now if you turn the key to ON/RUN and the gauges turn on, then don't bother looking

And still need to do this

I replaced the spark plugs. The gauges and switches work/turn on. Picking up voltmeter later. Thank you

 

[ChrisC631]

Pull the distributor cap and have a look under it to see what the contacts look like.
If you can get a hold of a timing light, put it on the coil wire when cranking to see if it flashes

Thank you for the help. I have spark. I got her to start by spraying starter fluid into the carburetor. Stayed on for about 10-12 secs then shut off. I noticed to the bottom left of the circuit breaker, there are about 8 screws with wires connected to them. One was corroded and I cleaned it up and it started again but shut off...

 

[alldodge]

Starting fluid (either) is not good to use because it can break rings. That said it ran for 10-12 seconds. So it went from a spark issue to a fuel issue as I see it

 

[ChrisC631]

Starting fluid (either) is not good to use because it can break rings. That said it ran for 10-12 seconds. So it went from a spark issue to a fuel issue as I see it

Ah f*** I didn’t know the starting fluid was a bad thing. Thank you for the heads up. I noticed a little bit of leakage asa well from one of the seals. Will remove and examine. Going to also change the fuel pump as the previous owner stated he recommends i change it.

Thank you you for all the help. I really appreciate it.

 

[nola mike]

Which seals? I'd check/change out the fuel filters and rebuild the carb before changing out the fuel pump.

 

[alldodge]

didn’t know the starting fluid was a bad thing.

Best not to use, things can break if more then just a little bit is used and should be sprayed at the carb, not in it from a distance so it mixes with the air

 

[ChrisC631]

Which seals? I'd check/change out the fuel filters and rebuild the carb before changing out the fuel pump.

Seems like a gasket from the carburetor. Will take pictures and post later.

 

[ChrisC631]

Which seals? I'd check/change out the fuel filters and rebuild the carb before changing out the fuel pump.

Seems like the carburetor was not screwed in tightly enough. I took a wrench and tightened the bolts up and no more leakages like before. She started again but shut off as I gave it some gas and then it cut off.

Now my power trim does not work. I apologize for the delay in the response. Unfortunately I cannot work on the boat as often as I would like due to work and family commitments.


Thank you you for your help

 

[Mad Props]

If you pump the throttle on the carb several times, can you see fuel spraying into the primaries? If not, your accelerator pump circuit is clogged which means other things can be clogged... I know you said you rebuilt the carb, but did you clear all of the carb passages with carb cleaner and compressed air?

 

[Glipat]

Did you verify the ignition switch located under the distributor cap? I replaced the cap, rotor, wires, coil, and plugs before I changed that switch. My boat would be so very difficult to start because it wouldn't detect a spark even though there was spark. It was like $100 CAD part. 15- 20 mins to replace. I only replaced it after my buddy suggested it.