4.3 Merc will not start

[tystick]

1990 merc 4.3l with alpha 1 drive

I was cruising out from dock when at slow speed (no wake) i hit a sand bar and stalled out and would not start - Engine will crank / turn over but will not start. :/

I do not see gas going into carb - I tried pouring gas in but that did not help.

I have a mechanical fuel pump which i inspected and it had no debris.
could be coincidence that it is fuel related issue at the exact moment it hits sand bar?

i am getting frustrated as it always seems like another problem crops up as soon as i fix one!!!!!!!!!

 

[Don S]

Re: 4.3 Merc will not start

Do you have spark? Did you knock the safety kill switch lanyard off by some chance?

i am getting frustrated as it always seems like another problem crops up as soon as i fix one!!!!!!!!!

Welcome to the wonderful world of OLD boat and engine repair.

PS: New ones aren't much better.

 

[tystick]

Re: 4.3 Merc will not start

SOB :/
It started right up in driveway this morning.

I guess it was flooded or there is something that gets sucked up in gas tank or hydrolock.
I am relieved in one way but would really like to know as it makes me a little nervous.

If it floods then what is best way to start? I might have
made things worse by pouring gas into carb throat and repeated attempts to start yesterday.

 

[Don S]

Re: 4.3 Merc will not start

If you suspect flooding, just hold the throttle wide open while cranking. When it starts, be sure to pull it back so it don't over rev.

 

[Bondo]

Re: 4.3 Merc will not start

If it happens Again,..........

Pull a Spark Plug,+ Look,.......... Then you'll Know what to Fix.........

 

[tystick]

Re: 4.3 Merc will not start

I tried throttle wide open but it did not catch...this could mean I did not try long enough or it was not flooded.
The former PO mentioned that he did experience hydrolock once
Is there anything on the 4.3 that is known to cause sudden stall? or is this possibly trying to tell me to save up for the carb rebuild?
FYI:
I do know that when filling gas tank, it will spit out if filled too fast. I tried to clear out vent tube but it did not help. I just have lived with it. I have no idea if this is related but had to ask

 

[Don S]

Re: 4.3 Merc will not start

Hydrolock is not caused by gas, it's caused by water in the cylinders and stops the engine from turning over.
And when you say sudden stall, if you are talking about the engine stopping instantly as if a steel block was installed in a cylinder and the piston hit it, then yes that could be hydrolock.
That would be from a cracked head, cracked block, blown head gasket, or somewhere that would allow the engine to suck in water during the intake stroke, and stalling the engine. This usually results in bent/twisted rods along with other damage.
Now if you are just saying that it cranks over fine, and doesn't start, then that could be a hundered different things.
But do like Bondo said. Pull the plugs and look at them, are the wet with gas? water? not wet at all? Do any of them look brand new like they have never fired.
You need to read those plugs, they tell a story ya know.

 

[tystick]

Re: 4.3 Merc will not start

I will check plugs next time
I just want to get a handle on this as what to do if it happens again.

If the prop was stopped from sand bar while at slow speed stalling the engine , would it most likely flood carb out?
Given that it starts right up the next day narrows the possibilities.