Mercruiser 4.3lx Clunking. PLease Help

[Aquatron]

Alright replaced intake for a crack and water on pistons. When I remove the plugs turns over without issue as soon as I put one plug in no matter what location. It turns over and then Clunk.

It seems like it has water on the pistons. I changed oil again and turned it over making sure I pushed all the water out. When I turn it over no signs of water.

Now I am lost. I was thinking distributor 180 out but no wires hooked up at all. When I install plug I don't hook up plug wire.

I went to a different forum to ask a question because I screwed up my password for Iboats.

Well won't do that again advice telling me to trash the motor and get a drop in replacement. If I could afford a drop in replacement I would but trying to salvage this one.

There might be a point when I have to do that, but I am holding on to hope...So please some just some advice...

 

[NHGuy]

Re: Mercruiser 4.3lx Clunking. PLease Help

So when you cranked and it stopped, did you then remove the plugs to crank it, and was there then water in the combustion chambers? That is, when you crank it after removing the plugs does water come out of the plug holes?

 

[Aquatron]

Re: Mercruiser 4.3lx Clunking. PLease Help

When I first tried to start it with plugs out I had water. Then after a oil change and turning over several times now no sign of water.

 

[dubs283]

Re: Mercruiser 4.3lx Clunking. PLease Help

is the battery fully charged??

all cables and connections clean and tight??

 

[Aquatron]

Re: Mercruiser 4.3lx Clunking. PLease Help

Yep..

 

[WSKIPPER]

Re: Mercruiser 4.3lx Clunking. PLease Help

Yep..

Is it on a trailer or in the water?...if on trailer try to start briefly with no water to see if it is hydra-locked from water intrusion...this will help to determine which problem you may have...I suspect other issues may be present...Bill

 

[bonzoscott]

Re: Mercruiser 4.3lx Clunking. PLease Help

Not sure of what all happened with the water intrusion but first thought comes to mind (cranks w/plugs out - no crank w/plugs in) is one or more valves are not opening. You might pull the valve covers and verify the valve train is functioning, cranking slowly with a breaker bar. That is, if you can use a breaker bar. If not, have someone turn the key.

 

[Aquatron]

Re: Mercruiser 4.3lx Clunking. PLease Help

Well I have a Bora scope and I crank it over and I can see all the valves opening and closing.

 

[dubs283]

Re: Mercruiser 4.3lx Clunking. PLease Help

have you load tested the battery??

what is the vintage/condition of the starter motor??

 

[Aquatron]

Re: Mercruiser 4.3lx Clunking. PLease Help

Thanks for all the help.

Yesterday I got it started once plus made sure timing was not out 180. Timing checked great.

Still getting a clunk and sometimes a grind on starter. I replaced with a after market starter and I think I might need to shim it. I have never shimmed a boat starter, but I guess just like a car if you use after market stuff to save cost you will still need to shim. That's why its CHEAPER it's not the same quality as OEM.

If this doesn't sound like a logical solution please let me know. Removing the starter two and three times yesterday inspecting the ring gear takes it's toll on this old man...

Thank, again

 

[Aquatron]

Re: Mercruiser 4.3lx Clunking. PLease Help

I just examined the teeth on the starter and it looks like the top of the teeth are wearing at a angle.

I think my worst fear is coming true..The PO did a repair job on one of the starter mount holes. Looks like a weld job. I think under load starter is pulling away from flywheel causing all the clunking sound.

I will go home and try to shim but don't think it will fix it...

Any advice on a fix?????? The motor is running about 150 plus on compression.. So scraping the motor kills me to even think about it...If I have to crazy glue the starter in I will. HAHA