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350 no start

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redsnapper386

Regular Contributor
hi guys i tried to start my 1987 350 a-1 today with no luck.the starter spins the motor real good.i got a backfire through the carb one time with no start. the boat has sat awhile and back in the summer we installed a hei distributor and it ran good.i have fresh gas,strong 12 volts. thanks in advance for help and in put.what to check.
 
It's either no spark or no fuel or both. Pour an ounce of fuel into the carb throat, install the flame arrestor and see if it tries to start. If it sputters you found the problem.
 
Your Merc A drive requires a SI (shift assist).
This SI system interrupts and stumbles the ignition during a shift from gear back into neutral.
If the SI micro switch is hanging up, it could be the source of your problem.

You may want to do one of several things:
** check the adjustment and function of the SI.
** temporarily and momentarily disconnect the SI, and give it a try.



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ricardo,thanks for your reply.i installed a new shift assembly.this sea ray was completely rebuilt .i also have a history on this site that i re read.i got so discusted that i quit working on it. what i dont get is before the motor was reinstalled we ran the motor on the ground to check it out and to break in the cam.it was prefect. now we put motor in boat hook up all wires and componets and it ran good in the boat for 39 hours.now im back to same problem.no start. i even installed a marine hei dizy.there is something some where in that wireing thats kicking my*****. i am going to start from sratch with a wire schematic and retrace my work. this sea ray is full of wires. is there a way to do by pass wireing to keep it running.i dont like the idea but i have heard of it. is it safe to do so.thanks again.
 
You will want to repair it correctly. Have measures will avail you nothing. This system is quite simple. You will need a good volt meter and a schematic and in no time you will find the problem.
 
You sound frustrated...I would be too. Just don't overthink it and keep it simple. Since the "starter spins the motor real good.i got a backfire through the carb one time" start w/a timing light to check for base timing. Back firing is either a lean fuel condition or timing is off. I use a small plastic medicinal syringe to squirt fuel into the carb.
 
I'm with Chris!
Look at your OEM schematic and trace out your wiring system.
With the dog clutch A drive, the SI is absolutely required in order to make a shift from gear back into neutral!
You will not want to circumvent or disable the system!

If you need to circumvent or disable this for troubleshooting, go ahead. Just don't operate the boat near the dock or other boats under these conditions ....... because you may not be able to achieve neutral!


While not ideal, the SI can be made to function correctly.


In order for this engine to fire up, you'll need the correct camshaft timing, the correct ignition timing, correct fuel/air delivery, cylinder pressure, and ignition spark!
Is all of this in order????

Are you able to create a spark event by rotating the distributor housing CCW while it's powered up?
Have you timed the ignition for #1 cylinder near 6 or 8 degrees BTDC on the compression stroke?



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guys thanks again.i am feeling a little better, i just finished a volt test.here is. 12.41 volts at the battery posts,12.21v coming out of coil. i am going to spark test every spark plug next,does the voltage sound ok.next i will start a timing check.i wanted to post this progress to you guys so far.i will post with results as i go.i feel better to know i have good volts without going into a wireing mess.i hope the harmonic balancer has not spun on me. my rotor turns good so i know it did not jump timing.thanks again awhole lots.will post more
 
guys thanks again.i am feeling a little better, i just finished a volt test.here is. 12.41 volts at the battery posts,12.21v coming out of coil. i am going to spark test every spark plug next,does the voltage sound ok.next i will start a timing check.i wanted to post this progress to you guys so far.i will post with results as i go.i feel better to know i have good volts without going into a wireing mess.i hope the harmonic balancer has not spun on me. my rotor turns good so i know it did not jump timing.thanks again awhole lots.will post more
 
Try this first

If you have 12.21 volts on the - neg side of the coil.

How many wires are connected to that terminal?

One should be grey (TACHOMETER)
One should be going to the shift interrupter switch.

Is this so?

if not then find the interrupter switch and tell us where the wires go, One should be going to ground the other should be going to the neg side of coil. When your original thunderbolt ignition was in place the other wire from the switch was most likely going to the green with white stripe wire going into the ignition timing module that was attached at the elbow (little black box with wires).

Also if you have a bad tachometer then this could be an issue shorting the coil out...

disconnect the grey tach wire and retest before doing any other checks/test....




To eliminate any dash side wiring issues you need to make a jumper device.

you will need two toggle switches, one a ON/OFF the other a momentary on.

connect a 16 ga wire to one terminal of both switches and have a 6 ft length also from this connection with a alligator clip on it. Use red wire if possible, this will connect to the battery.

Of the on/off switch other terminal connect a purple wire if you have that color, 6 ft long with a alligator clip on the other end. This will connect to the coil +

The last terminal on the momentary switch use a yellow wire if you have that color 6 ft long with a alligator clip on the other end. This will connect to the small post on the starter solenoid that has the yellow with red strip already attached.




Make sure your on/off switch is OFF before connecting these clips.

Disconnect the main wire harness big black connector.

Once the leads are attached to there correct locations, turn the on/off ON, this will apply power to the coil and anything else on the IGNITION ON circuit.

Now activate the momentary switch and this will crank the engine over. If all is good it will start.

If not and the motor does not start then it is either the distributor is bad (something inside maybe) or something with the motor (pulling the plugs and making sure they look normal needs to be done to be sure nothing internal or water is there)

*****NOTE: if the engine starts the ONLY way to stop it is to turn the ON/OFF switch OFF!!!!!!!*******


Here is a quick illustration of the switch rig if needed. best to use 16 gauge wire or thicker if you have any and try to use the appropriate colors to match what is at each connection point already.
 
If you do a PPS procedure, use at least 25 degrees separation. IOW, run the stop out/down further!
IMO, a 10 degree spread (20 total) is not enough for accuracy.
 
thanks ricardo,how far should i run out the all thread.i heard 1/2 inch on 350 5.7.im in the dark here as this is my first try at this procedure. is the goal to determine if the har bal is true and stable,and to get a true tdc.correct me if im wrong.thanks
 
As far as his timing is concerned, we dont even know if he has any spark.

Lets get that information first. If there is spark he can hook up a timing light while cranking the motor over to get a visual and see if the timing is anywhere near where it should be. If it is not then go down the path of TDC and timing mark location......Motor was already running so if the timing is out then it is either a distributor issue or a timing chain issue or a cam gear/dist gear issue.......

Dont think we are there yet.

Troubleshoot spark first..........
Spark plugs second
then timing

For all we know he could have water in the cyclinders.........

in my opinion.......
 
redsnapper386 said:
thanks ricardo,how far should i run out the all thread.i heard 1/2 inch on 350 5.7.im in the dark here as this is my first try at this procedure. is the goal to determine if the har bal is true and stable,and to get a true tdc.correct me if im wrong.thanks
Click to expand...

If the harmonic balancer is not stable you have issues.

If it is intact and not seperated and the key has not sheared then you should be fine.
But again lets start at square one

1 spark/ignition
2 spark plugs
3 timing
 
redsnapper386 said:
hi guys i tried to start my 1987 350 a-1 today with no luck.the starter spins the motor real good.i got a backfire through the carb one time with no start. the boat has sat awhile and back in the summer we installed a hei distributor and it ran good.i have fresh gas,strong 12 volts. thanks in advance for help and in put.what to check.
Click to expand...

Ayuh,.... Sure sounds like ya stabbed the distributor in, at 180° Off,....

On the Tdc, Exhaust, insteada Tdc, Compression stroke,...
 
redsnapper386 said:
thanks ricardo,how far should i run out the all thread.i heard 1/2 inch on 350 5.7.im in the dark here as this is my first try at this procedure. is the goal to determine if the har bal is true and stable,and to get a true tdc.correct me if im wrong.thanks
Click to expand...
I would not be able to suggest a dimension! You will just have to experiment, and learn approximately where the piston will be stopped in relationship to crankshaft angle!

The angle itself is not important. It could be 27° BTDC and ATDC, or it could be 31° BTDC and ATDC!
The important part is that you give it enough spread as to create accuracy when this angle is "split"!

Example:
If we used 8* BTDC and ATDC, we would be too close to the top of the crankshaft throw.
If we increase this angle BTDC and ATDC, we gain accuracy when the angle is split in half!


Ideally, a degree wheel and temporary pointer are used when doing a positive piston stop procedure.
The pointer is moved until we see the same angle being shown at BTDC and ATDC.
Once this has been achieved, the piston stop is removed, and we then roll the engine over until the pointer aligns with zero on the degree wheel.
Theoretically, we now have a true TDC!
We then re-mark the balancer for TDC as per our timing tab location.

You can then "stake" the balancer in two locations, so that it can be checked in the future to see whether not it continues to slip!
If the two stake markings continue to align, all is good!


But I agree...... we are getting off track here!
You need to focus on why this engine is not firing for you.

Even if your timing marks are not completely accurate, I would suggest that you bring it around to #1 cylinder TDC on the compression stroke.
Remove your distributor cap, and check to see if the rotor is aligned with the cap plug wire socket that leads to cylinder number one.

That would be a good starting point!
Yes..... Pun intended! :D



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TMI (Too Much Information) the problem is going to be simple. According to the original post the engine was running and now it isn't. I doubt the distributor is out of time with the camshaft.
 
AMEN! I totally agree w/Chris and Rick. You don't pull a tooth because it aches...find the root of the problem...no fuel or spark to start; which is it?
 
You may want to check the fuel pump. ABYC doesn't allow for the fuel pump to run anytime the engine isn't turning. So to fix this, they power the fuel pump solenoid from the secondary start solenoid (starter slave solenoid in the schematic), to turn on the fuel pump during start. Afterwards, it is usually powered either through an oil pressure feed or a feed tap off your alternator.

Try having someone touch the fuel pump while you are turning the engine over. (carefully I might add). If you don't feel the fuel pump kick on, that could be your problem.
I would check the lead from your secondary start solenoid to the pump. It could be simply the solenoid itself. Easy fix. (there are 2 small posts on the secondary start solenoid. One is the key in (activation) and the other is a simple 12v out, not a ground. That will be the post you should be looking at)
 
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Chuck Green said:
You may want to check the fuel pump. ABYC doesn't allow for the fuel pump to run anytime the engine isn't turning. So to fix this, they power the fuel pump solenoid from the secondary start solenoid (starter slave solenoid in the schematic), to turn on the fuel pump during start. Afterwards, it is usually powered either through an oil pressure feed or a feed tap off your alternator.

Try having someone touch the fuel pump while you are turning the engine over. (carefully I might add). If you don't feel the fuel pump kick on, that could be your problem.
I would check the lead from your secondary start solenoid to the pump. It could be simply the solenoid itself. Easy fix. (there are 2 small posts on the secondary start solenoid. One is the key in (activation) and the other is a simple 12v out, not a ground. That will be the post you should be looking at)
Click to expand...

Chuck.......he has a carburated motor and a mechanical fuel pump....your posty relates to a electric fuel pump............does not apply here.
 
Been away for a while. Just read this thread. This is a perfect example of checking if a device is plugged in first. Somebody said it earlier; do we have spark and fuel?? No sense in checking anything else until that is determined.
 
So far I have not read that the fuel test has been made. Did I miss something? Having set for a while, it could be something as simple as a gummed-up float valve not letting gas enter the carb. I see this a lot every spring on both friends' boats and their lawnmowers, and on generators in the winter when power lines fail from ice storms.
 
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