overheated 92 454 (330hp) - now slow to turn over and no compression on many cylinder
#21
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Definately not close to what its worth up north here in Canada - you couldn't even get a dual axle boat trailer for that - here the trailer is easily between $2500 to $3000 alone. And then for even 70s and 80s 18' basic runabouts with small motors, people ask $5000+. Everything is expensive up here.
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Definately not close to what its worth up north here in Canada - you couldn't even get a dual axle boat trailer for that - here the trailer is easily between $2500 to $3000 alone. And then for even 70s and 80s 18' basic runabouts with small motors, people ask $5000+. Everything is expensive up here.
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Update - got my breaker bar out and socket and first went to crank with the starter - as usual it was slow and then within 5-10 seconds virtually stopped. I then got my breaker on the crank and tried to turn manually - it turned NO PROBLEM - I KEPT TURNING IT AND IT WAS TURNING EASY WITH THE BREAKER. So would that suggest my internals are OK, and instead I have a starter or other electrical issue????? Is it possible to get zero compression if the engine is turning too slow (like 1 rotation every second slow)?????
One other thing I noticed (maybe this can shed some light on my issue) - I removed the wire from the coil to the distributor when cranking from shore and noticed when I first try to crank with starter I get sparking out the coil about every second but after 5 seconds (when the cranking starts to slow down) I get no more sparking even though the engine is turning over (mind you real slow) - is it not sparking just cause the engine is cranking too slow to create a spark?
If this concludes my inner motor is OK and I have electrical issue, could that have been what caused it to stall and start overheating? Keep in mind it is a 92 merc which from what I understand don't need much battery power once started - so again what type of electrical issue could have caused the overheat and stalling??? I know my starter may be the issue of why it is turning slow, but obviously that would not have caused it to stall and overheat. Any ideas where to start diagnosing this?
Thanks
One other thing I noticed (maybe this can shed some light on my issue) - I removed the wire from the coil to the distributor when cranking from shore and noticed when I first try to crank with starter I get sparking out the coil about every second but after 5 seconds (when the cranking starts to slow down) I get no more sparking even though the engine is turning over (mind you real slow) - is it not sparking just cause the engine is cranking too slow to create a spark?
If this concludes my inner motor is OK and I have electrical issue, could that have been what caused it to stall and start overheating? Keep in mind it is a 92 merc which from what I understand don't need much battery power once started - so again what type of electrical issue could have caused the overheat and stalling??? I know my starter may be the issue of why it is turning slow, but obviously that would not have caused it to stall and overheat. Any ideas where to start diagnosing this?
Thanks
Last edited by dna; 07-08-2018 at 11:12 PM.
#25
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You do not have an electrical issue. When power is interrupted to the coil it will discharge the stored energy. I would first deal with a new starter and make sure your engine survived. Once you have completed that you will have to address you cooling issue. Not knowing the maintenance history, I would start at the raw water pump. Back flush from the pump to the drive. One thing I have seen (mostly salt water applications) is the water hose from the drive to the transom, where it enters the transom the housing corrodes and closes up causing a restriction. Now let's do a hypothetical situation, You put in a new marine stater and the compression test is good and you found the raw water pump failed (rebuilding it fixes the overheat) you think you are all set but you are not. Being a 1992 do you have the history on all maintenance done? It is a wet joint exhaust system and your stalling could be the manifold to riser joint is failing (also a potential cause for overheat) meaning it is time for new manifolds and risers. Some of the crackling noise you heard was the rubber bellows exhaust hoses melting. I would also imagine you exhaust flapper are destroyed as well from the overheating. Oh and one more thing (there are many others) the engine oil is now most likely toast due to it too was overheated. I have seen when a do it yourself'er fix the overheat issue only to have the engine fail due to lack of lubrication. One step at a time so you don't get in too deep. As a forum we are here for you.
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You do not have an electrical issue. When power is interrupted to the coil it will discharge the stored energy. I would first deal with a new starter and make sure your engine survived. Once you have completed that you will have to address you cooling issue. Not knowing the maintenance history, I would start at the raw water pump. Back flush from the pump to the drive. One thing I have seen (mostly salt water applications) is the water hose from the drive to the transom, where it enters the transom the housing corrodes and closes up causing a restriction. Now let's do a hypothetical situation, You put in a new marine stater and the compression test is good and you found the raw water pump failed (rebuilding it fixes the overheat) you think you are all set but you are not. Being a 1992 do you have the history on all maintenance done? It is a wet joint exhaust system and your stalling could be the manifold to riser joint is failing (also a potential cause for overheat) meaning it is time for new manifolds and risers. Some of the crackling noise you heard was the rubber bellows exhaust hoses melting. I would also imagine you exhaust flapper are destroyed as well from the overheating. Oh and one more thing (there are many others) the engine oil is now most likely toast due to it too was overheated. I have seen when a do it yourself'er fix the overheat issue only to have the engine fail due to lack of lubrication. One step at a time so you don't get in too deep. As a forum we are here for you.
So said that you didn't think I have an electrical issue. So do you think the hard turning and zero compression I have is internal to the motor - that was my point on my last thread that when the starter is barely able to turn over the motor (making it look like the engine is partially seized), I can easily turn it with the breaker bar - that makes me think I do have an electrical issue. I know the starter may be one of the issues, but obviously not the main issue cause that would have not caused the overheat and stalling. Keep in mind that I never got the engine into the red section on the gauge - I got it to 180 but the red is 220-240. Would that still be considered overheating the engine? Though to be fair I only looked at the gauage after the engine stalled and was off for about 20 seconds - but if it did get to 220 I doubt 20 seconds would cool it down to 180.
A new question - what would be the likely reason the engine stalled if it got to 180? I don't think these engines have an auto shutoff feature when the engine is getting hot, so to stall it either lost fuel, air, compression, or spark. I doubt fuel and air is the issue - so it stalled due to compression or spark. And based on my posts, I have both issues - no compression and limited spark out the coil - but I think both are due to it turning over slow right now. But what type of electrical issue would have caused the limited to no spark issue which could have caused it to stall? I know my batteries are 100%, so where should I look.
Thanks
#27
Let's discuss the over heating/180 not overheating.
If your engine was crackling like a bowl of rice crispies your engine got HOT as in way overheating. So why did the temp gauge not show this. The gauge must be submerged in water to work correctly. If a plastic bag etc were to block your water inlet on the drive the engine will starve for water, over heat and the temp gauge will not show the overheating condition and the alarm most likely will not sound, as the temp probes are no longer submerged in engine water to measure. Continue to run engine for a minute or so and you will start to have engine seizure.
I don't know this is what happened but my money is on this as a viable explanation to what happened.
If your engine was crackling like a bowl of rice crispies your engine got HOT as in way overheating. So why did the temp gauge not show this. The gauge must be submerged in water to work correctly. If a plastic bag etc were to block your water inlet on the drive the engine will starve for water, over heat and the temp gauge will not show the overheating condition and the alarm most likely will not sound, as the temp probes are no longer submerged in engine water to measure. Continue to run engine for a minute or so and you will start to have engine seizure.
I don't know this is what happened but my money is on this as a viable explanation to what happened.
#28
Alex, If you like the boat you may want to start looking for a low hour boat that has good mechanicals but neglected interior and hull/gelcote.
I have found these for as little as $ 500 with a 454 and bravo. Just keep looking and marry the mechanicals of one to the hull of the other. You will end up with lots of extra duplicate parts and can sell many to almost pay for the donner boat.
Just another idea trying to help you out. Good Luck.
I have found these for as little as $ 500 with a 454 and bravo. Just keep looking and marry the mechanicals of one to the hull of the other. You will end up with lots of extra duplicate parts and can sell many to almost pay for the donner boat.
Just another idea trying to help you out. Good Luck.
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Update - well I had a spare marine battery so for ****s and giggles I swapped it in and tried again - it is now turning fast and back to normal and sparking out the coil like ****. So I continued with compression test and unfortunately did find some issues. All were at 120+ except 3 at 80, 5 at zero, and 2 at 50. I understand 3 and 5 cause they are beside each other which implies the head gasket (hopefully), but what would cause the low compression on the other side in just one cylinder? Either way, off with the head(s).
Thanks
Thanks
#30
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Update - well I had a spare marine battery so for ****s and giggles I swapped it in and tried again - it is now turning fast and back to normal and sparking out the coil like ****. So I continued with compression test and unfortunately did find some issues. All were at 120+ except 3 at 80, 5 at zero, and 2 at 50. I understand 3 and 5 cause they are beside each other which implies the head gasket (hopefully), but what would cause the low compression on the other side in just one cylinder? Either way, off with the head(s).
Thanks
Thanks