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4.3l mercruiser not starting

Z

Zach1278

New member
Started this morning but there was a grinding or almost a farting sound at startup. Issue got worse and now it just grinds when I turn the key and it fails to startup. I replaced the plugs which were wet but still same issue. I attached a video of failed startup.
 
Battery connections all clean? Starter connections clean. Good battery ? Do you have battery voltage at the starter? Test the voltage at the slave solenoid.
 
Pull spark plugs, if it doesn't have seawater pump on front of crank pulley , hand bar engine over with socket on big bolt in the center of pulley. See if motor turns over now and how much water comes out spark plug holes. If still grinding if motor was hydro-locked(water on top of pistons ) he bendix on starter is bad. When you turn engine over by hand , you are moving flywheel ring gear , which gives you good flywheel ring gear teeth. If same problem , after you check bendix gear on starter. I'd say ring gear on flywheel.
 
hand bar engine over with socket on big bolt in the center of pulley.

Please stop giving out this bad information unless you also tell them they can break the bolt in the crankshaft and will have to get the motor disassembled for repair. You use this to turn a crankshaft
cca-4797_w_ml.jpg
 
Looks like a newbie "expert" has decided to spew un wanted, un needed and inexperienced advice....ugh..
 
........................
Mikey N.C. said:
Pull spark plugs, if it doesn't have seawater pump on front of crank pulley , hand bar engine over with socket on big bolt in the center of pulley. See if motor turns over now and how much water comes out spark plug holes.
Click to expand...
I'm with Ed on this one..... this is NOT advisable.
If that bolt was to break, you'll be pulling the engine out for a rather expensive machine shop bolt fragment extraction.

Mikey N.C. said:
If still grinding if motor was hydro-locked(water on top of pistons ) he bendix on starter is bad. When you turn engine over by hand , you are moving flywheel ring gear , which gives you good flywheel ring gear teeth. If same problem , after you check bendix gear on starter. I'd say ring gear on flywheel.
Click to expand...
I highly doubt that this 4.3L engine was equipped with an old Bendix style starter motor.

Bendix vs solenoid action starter motors.jpg

Bt Doctur said:
hand bar engine over with socket on big bolt in the center of pulley.
Click to expand...

Please stop giving out this bad information unless you also tell them they can break the bolt in the crankshaft and will have to get the motor disassembled for repair.
You use this to turn a crankshaft
cca-4797_w_ml.jpg
Click to expand...

kghost said:
Looks like a newbie "expert" has decided to spew un wanted, un needed and inexperienced advice....ugh..
Jack, I see that you now have another target.
Again..... please play nicely!
Click to expand...

Bt Doctur said:
Jack, go take your meds already,
No kidding!
Click to expand...

kghost said:
pre scription ran out a while ago...
Most likely ran out of them several years ago!
Click to expand...

Mikey N.C. said:
With spark plugs out if he breaks bolt then lower unit or motor is locked up.
Again, not advisable.
Use the tool that Ed suggested, or use a strap wrench around the harmonic balancer OD.
Click to expand...
 
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Wtf
who on earth would write a post like that.

1. Who gives an f about your opinion on anything or if you agree with anything. You agree why? Are you some kind of expert? If you feel this way then it is only your opinion as noone else feels this way and would never use ricardo and expert in the same sentence...ugh.
2. The bendix response. Are you really that f'n stupid!
It was not meant to refer to an actual old bendix.
I use this term all the time. You really are a f'n moron!!

Again another usless, uniformative post that has no value to the suject but only to increase post count.

You are truly pathedic!
 
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Mickey, I believe that you missed the point.
The center crankshaft bolt is to be tightened to a specific torque value.
If you need to exceed that value (in order to rotate the crankshaft with it), you will put that bolt at risk.
Its not worth the risk!

As far as your question regarding; “how many broken bolts have you seen?“...... I’ve seen zero, because I’ve not been foolish enough to use that bolt to turn a difficult-to-rotate crankshaft.


.
 
Last edited:
Zach1278 said:
Started this morning but there was a grinding or almost a farting sound at startup. Issue got worse and now it just grinds when I turn the key and it fails to startup. I replaced the plugs which were wet but still same issue. I attached a video of failed startup.
Click to expand...
Pull the plugs again. If theyre wet is it gas or water? Check oil. If there's water in oil the engine was hydrolocked.
 
Interesting post,

Says a specific torque spec but has no spec. Useless!!
Suggests it could break but has never seen one break.

Tells me there nothing to the post but increase in post count.

I guess the thing to do is remove potentially breakable bolt and install one that wont break while turning over a V6 with no compression.

Oh wait....but thatvwould have required an answer not opinion.

Makes one wonder how did we get so far off the topic again.

More useless opinion and spew...
Opinion from who?

One who seems to have answers with no solutions.

The solution for the off topic was given.
Didnt need any additional spew. Just peat and repeat.

Maybe let others answer questions about the posted topic who can actually give answers and not opinion.
 
It does happen and the people who it happens to have not been advised of the correct way to turn a crankshaft.
Call any reputable machine shop and ask. Also ask how much to remove the engine, remove the crankshaft, drill and retap it because if you broke it the motor was not turning . Only the bolt getting tighter until it snapped,
An alt method is to remove the pulley and reinstall the 3 bolts and use a bar on them to turn a motor from the balancer.
If this is new territory to you, get the manual and read it. If your winging it , have a safe flight
 
I'm not winging nothing, any engine with spark plugs removed should bar over easy. If connecting rod is broke customer is a idiot.
 
Yes I know the differences, and No i`ve never tried to break one. When I assemble a motor thats the next thing that goes on the crank after the crank is dropped into a block. mains torqued, pistons and rods installed and torqued.
heads, pushrods and a static pushrod adjustment . then the cam goes in, timing chain, timing cover, and pullys and belts. and intake
#1 has been brought to TDC compression, pre oil the motor, install the dist
 
Hey Mikey your so fine hey Mikey.

Tell us all the difference between grade 3 and grade 8 bolts.

Inquiring minds want to know...
 
We have 3 jasper 4.3 engines, long blocks still wrapped on pallets at $4,200. setting on floor.
Main cause of engine failure is freezing and cracks along push tubes in valley.
 
Great!
I just had a fudge brownie for desert.

Probably be dropping a jasper or two myself pretty soon...

Not sure what having 3 failed engines has to do with the China trade talks....??????
 
Khos. Grd 3 is a sheer bolt like you would use on application , for say pto drive on different applications such as Bush hog on tractor , drive train applications where it is a sheer pin. Grd. 5 is used in applications for where you need some give as in clutching situation. Grd 8 is for no give. Do you know what the hashes marks on head of bolt are to tell differents ?
 
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