Mercruiser 4.3L lift points

[liusigou]

The exhaust water is very warm while my engine runs. Is it normal or not? The temp shows only 50 ceis but it is at least 80.

 

[alldodge]

It's normal on a hose. The hose cannot provide enough water

 

[liusigou]

Yes. I think so. there are 6 cylinders for this engine and it releases more heat than 4 cylinders motor.

 

[liusigou]

I cannot start engine any more.. The motor sometime moved and some times cannot move after I tested in the water and there is a click voice from engine, Is the starter bad? the output voltage is 12.64.

 

[Lou C]

A couple things
One if the engine doesn’t crank over I would first remove the spark plugs to make sure there is no water in the cylinders. If there is you have to find out why it could be an exhaust problem or another engine problem. If not then you have to troubleshoot the starting system.
That in-line fuel filter does not belong there it is a safety hazard (explosion & fire risk) if it leaks. You should have a proper water separating fuel filter with a metal canister ONLY with inboard gasoline engines!

 

[Lou C]

Yes. I think so. there are 6 cylinders for this engine and it releases more heat than 4 cylinders motor.

Actually you should not have steam like that esp with the engine temp of only 120*F. You problem is that the rubber hoses feeding the exhaust elbows are kinked (too short) and the elbows are likely not getting enough raw water flow hence the exhaust steam.
My OMC Cobra has the same engine and when running on the host it never steams like that and the exhaust water is warm but not hot.

So replace those hoses with ones that are long enough so they don’t kink & get rid of that in-line fuel filter. In the USA Coast Gard regulations prohibit plastic or glass fuel filters in an enclosed engine space with a gasoline fueled engine. Metal only.

 

[liusigou]

Actually you should not have steam like that esp with the engine temp of only 120*F. You problem is that the rubber hoses feeding the exhaust elbows are kinked (too short) and the elbows are likely not getting enough raw water flow hence the exhaust steam.
My OMC Cobra has the same engine and when running on the host it never steams like that and the exhaust water is warm but not hot.

So replace those hoses with ones that are long enough so they don’t kink & get rid of that in-line fuel filter. In the USA Coast Gard regulations prohibit plastic or glass fuel filters in an enclosed engine space with a gasoline fueled engine. Metal only.

Did you see the attached video I uploaded before, it runs great. But it failed to start after I run it in the water. Sometime the engine move after I hit the starter with a hammer.

 

[Lou C]

You have the old big Delco style starter or the newer smaller PMGR style? If the Delco you probably need a new solenoid. If the newer smaller style do not hit these with a hammer it will break the magnets inside! However first check every connection in the starter circuit & battery cable terminals, including grounds.

 

[liusigou]

You have the old big Delco style starter or the newer smaller PMGR style? If the Delco you probably need a new solenoid. If the newer smaller style do not hit these with a hammer it will break the magnets inside! However first check every connection in the starter circuit & battery cable terminals, including grounds.

Now I do not know what style the starter is. I saw the previous owner hit the starter with a hammer but softly.

How can I there is water or not in the cylinders? Also I did make the connection shining with sand. I will check the starter again, it should come out to bit the flying wheel. If it does not come out for engage, it means starter is bad

 

[Lou C]

You can tell if there is water in the cylinders by removing the spark plugs & cranking the engine over (try to start it). If water comes out of the spark plug holes that’s bad; it could be a leaky exhaust system (remember the exhaust system on inboard boats is water cooled) or an internal engine problem (leaking head gasket or cracked cyl head). I mention this because sometimes the engine won’t crank over not because the starter is bad but because a cyl is full of water which can’t be compressed like air can, so the engine doesn’t turn when you engage the starter.
If you’re lucky you just need a new starter.

 

[liusigou]

Bad news. Water in the cylinders, Can it be fixed?

 

[alldodge]

Yes, remove all plugs
Get some oil into each cylinder and crank it some.
Put some more oil in and crank it some more

Now figure out where the water came in from

 

[liusigou]

Now I removed all the sparks, some do not have water and some have. and I cannot crank over the engine and I turned it manually. But I cannot find water from spark hole.

 

[alldodge]

Sure sorry but guess we have a language barrier
You cannot crank over the motor?

 

[Lou C]

You seem to have at least 2 problems the water in the cyls & perhaps a bad starter.
Now you have to figure out how the water is getting in (bad exhaust system, blown head gasket/cracked head) and repair that. Then change the oil repeatedly till you get the water out of the oil. Spray fogging oil in the cyls for now.
I’m had this happen to mine; had an overheat in 2013, ran ok for 2 more seasons then had water in cyls at the end of the 3rd season. Not enough to hydro lock it but enough to cause misfires & water (salt water) in the oil.
I changed the oil 3 times ran it long enough to get it hot then drained the block & exhaust. Exhaust tested fine. So I knew it was something internal. Wound up being leaking head gaskets on both sides & crack cyl heads. Did a top end overhaul in 2017, & it’s still running fine now, no water in the oil or cyls etc,…

 

[liusigou]

Sure sorry but guess we have a language barrier
You cannot crank over the motor?

No. I cannot crank over the engine. there is only a click voice. even it is very difficult to turn it over.

 

[liusigou]

You seem to have at least 2 problems thecwater in the cyls & perhaps a bad starter.
Now you have to figure out how the water is getting in (bad exhaust system, blown head gasket/cracked head) and repair that. Then change the oil repeatedly till you get the water out of the oil. Spray fogging oil in the cyls for now.
I’m had this happen to mine; had an overheat in 2013, ran ok for 2 more seasons then had water in cyls at the end of the 3rd season. Not enough to hydro lock it but enough to cause misfires & water (salt water) in the oil.
I changed the oil 3 times ran it long enough to get it hot then drained the block & exhaust. Exhaust tested fine. So I knew it was something internal. Wound up being leaking head gaskets on both sides & crack cyl heads. Did a top end overhaul in 2017, & it’s still running fine now, no water in the oil or cyls etc,…

I checked engine oil, it seems the engine oil is good. not milky

 

[alldodge]

No. I cannot crank over the engine. there is only a click voice. even it is very difficult to turn it over.

Are ALL of the spark plugs out of the motor?
If they are then the motor is locked up

 

[Lou C]

Yeah could be locked by rust in the cyls

 

[Lou C]

I checked engine oil, it seems the engine oil is good. not milky

It doesn’t always show on the dipstick right away; take off the oil cap on the valve cover & look inside