4.3 alpha one gen 2 prop strike engine will start but won't run

[S_WELLS]

94 mercruiser 4.3 alpha one gen 2 thunderbolt 4 ignition.

Idling out of the harbor and ran up on a shallow bank and dug the prop in the mud and it stopped the engine.
when I try to start the boat it will fire and burp a few times and die.

I have checked compression and all is well there.
Engine spins good doesn't seem like any internal damage.
Checked the timing and everything looks lined up when I get #1 up on tdc. rotor is pointing at #1 and if I spin the engine with a timing light it is firing correctly.

There was zero damage to the prop or skeg so I was hoping no outdrive damage but I'm not sure.

Would outdrive damage keep the engine from starting in neutral ?

Could the distributor be damaged ?
I replaced the cap and rotor because they looked suspect but it still sputters and dies.
I did notice that you could spin the old rotor a lil , maybe a eight of an inch at various positions in the revolution but with #1 at tdc it was tight with zero play.

My first thought was that it had jumped time but with everything lining up right on the timing and seeing that it is firing correctly I'm wondering if something in the outdrive is bound up and keeping it from running but seeing as how I don't know much about outdrive it seems that if the boat is in neutral that there wouldn't be anything in the outdrive engaged to stop the engine from running correctly.

Any advice is greatly appreciated !

 

[Rick Stephens]

Best way to know if drive is the problem is pull it, shove a cut off garden hose in the water inlet hole in the bell housing and see if it will fire up.

 

[achris]

Gear shifting is done in the lower part of the drive, not behind the engine. Even in neutral, everything in the drive is still engaged, and spinning.

Pull the drive (10 minutes job, see my videos, link at the bottom of my post signature), stuff a water hose into the water passage on the port side of the bell housing and fire up the engine....

Chris...........

 

[alldodge]

Engine spins good

Your checking spark with a timing light so it may or may not be good. Disconnect the shift interrupter to see if it will start

 

[S_WELLS]

Pulled the drive off today and no change.
Still starts and sputters for a second and dies.

Anyone have any ideas on where I should look next ?

 

[QBhoy]

Was it quite a fair old thud you hit it at ? Wonder if you’ve disturbed and taken up some crap in the bottom of the fuel tank ?
did it over heat afterwards at all ?
have you checked the plugs to see what they are like ?

 

[S_WELLS]

Not at all.
I was idling along about as slow as you can idle.
it wasnt a hard stop.
prop stuck in mud and killed the engine and it immediately would barely start and sputters and backfires and dies.
all indications point towards it being out of time but if you bring #1 up to tdc the line on the harmonica balancer is at 0• and the rotor is pointing to #1.
I'm starting to think it may be the distributor but I'm not 100% since I hooked up a light and #1 seemed to be firing in time.

I'd really appreciate any advice or suggestions anyone has.

thanks !!

 

[wellcraft-classic210]

Have you been able to verify fuel supply as in fuel pressure check and inspecting the contents of the fuel filter ? // A fuel supply issue will definitely cause sputtering. //

You may want to try dumping a little gas down the carb before you start it next time & see if runs strong for atleast few seconds.

// If it starts you have at least some spark // If its starts and dies after the test above its probably fuel system related.

 

[Rick Stephens]

I agree. Seems like the prop strike was coincidence. Might be time to do a carb rebuild and go through the fuel system. Engine firing up at all says you have spark.

 

[alldodge]

Remove spark plug 1, remove power to the coil, and crank the motor over holding your thumb on the hole. Just bump the starter, and once it blows you thumb off, check the timing mark on the damper, and check where the distributor is pointing

 

[achris]

It could be a dodgy key switch. Check you have power on the coil+ with the key ON...

Chris....