470 problems

[karayj]

Thank you all for the great advice. I will say my current drive is not pretty inside the impellar was totally shot. The shaft seal was missing. The tube that goes over the gear shaft keeps falling out of place. There is a crack up front shown in the 2nd picture.



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[karayj]

I replaced my water pump and impeller and to needed to move my shaft to align the key. Can someone tell me what direction I need to turn the gear selector to put in in forward before I re-connect the lower unit.

 

[stonyloam]

Back to winterizing, I don’t know what you did, but ALL YOU NEED TO DO IS PULL THE AFT PLUG ON THE HEAT EXCHANGER to drain the fresh water, and make sure your antifreeze is about 50/50 and you are good.

 

[karayj]

I will do that in a pinch as far as draining the water . I am trying to re-install by outdrive but it won't go up even if I move the shaft left or right a bit .
One thing you all should know that taking it off was so hard . I have to use a large screw driver to remove it. It seems sized in there. Any Ideas it is getting cold here and I"m running out of time . 21 degrees next week

 

[karayj]

:grumpy:
ALL set guys It was the Oring stuck inside I guess is came off the shaft. I put it back on the shaft with grease and going to tighten the bolts and pray .

 

[karayj]

Thank God this form is available you guys are so awesome helping me. So I have a new problem but at least I’m able to winterize it
when I was starting up the boat which took forever lots of starting fluid i I noticed some sparks by The alternator side of the harmonic balance .
When I was cranking it I even noticed it and I saw a couple of pieces of something flying out
no honestly I’m gonna start it tomorrow I’ll put my coolant through it and put it away but it’s going to be something I got to deal with in the spring any ideas?
and another problem I know he’s think it’s a carburetor but it feels like it’s running on three cylinders but when I remove the spark plug wires there’s a difference so it’s not that it’s not getting spark it’s something else but it has that same affect as if it’s running on three cylinders any ideas on that?

 

[stonyloam]

OK a loose magnet under the rotor, need to pull it and check. This is a 470 right, with a heat exchanger right? Just what are you putting coolant through? You should already have the block full of 50/50 auto antifreeze, so you DONO T NEED TO DO ANYTHING WITH. THE BLOCK! ALL YOU NEED TO DO IS DRAIN THE HEAT EXCHANGER! there are two plugs on the underside of the exchanger. You need the pul the farther aft plug (7/16 socket) to drain the raw water. Period done!

 

[karayj]

Oh man I will I know that I bought 6 gallons f the pink stuff any instruction on this method ?
SO I Don't not have to run anything through my outdrive till it turn pink? how about the other areas that have raw water ? I say a diagram and it shows raw water threw out the system.

 

[stonyloam]

OK, 89, 3.7 Mercruiser is there a rectangular cast iron tank with a radiator cap on the port side of the engine and a long 4” diameter tube with hoses going in and out of it? That is your coolant reservoir and heat exchanger. If you take off the radiator cap the tank should be full of automotive antifreeze (the green stuff) that circulates and cools the engine the same as in your car. The round tube is the heat exchanger that circulates raw water to cool the antifreeze, Same as the radiator in your car. The coolant in the block should be about 50/50 antifreeze mix so all you need to do with that is get a cheap antifreeze tester and check it. Should be good to -20°F. All you need to do now is drain the raw water from the heat exchanger. There are two plugs on the bottom aft of the exchanger. The front one drains the antifreeze DO NOT REMOVE THAT ONE, the aft plug drains the raw water, just remove it (drop it in a cup holder so you can find it in the spring) and let the water drain out. Then you are done with freeze protection. In the spring all you need to do is put that plug back in. No need for any antifreeze at all. If you have a 3.7 it should look like this https://bpi.ebasicpower.com/37special.html. If it doesn’t then you have something else.

 

[stonyloam]

OK, here is your coolant diagram (post #4) the only sea water is what goes through the exchanger and out the exhaust. https://forums.iboats.com/forum/engi...r-coolant-leak

 

[karayj]

Thank you Stonyloan the draining info is great I had most of that info but the correct side to drain I did not so thank you!!!
Now the 2nd issue the sparks when I was starting the boat and it was just turning over and 2 or three peices of someing flew out. (Felt like plastic)

I noticed metal to metal sparks 2-3 behind the harmonic balacer pulley (main Pulley) on the altenator side . The engine also vibrates , it has the same feel as whan you not runnnign on all cylinders yet I am. I pulled each plug wire and there was a change so the cylinders are getting spark.

Any help or ideas on that would be great .

 

[karayj]

One more thing to the experts out there . Since I have an alternator on my 3.7 then why do I have magnets AKA stator ? Is it possible someone did a conversions years back? When I winterized it today there is a clicking noise one the harmonicbalancer. I have a video are we allowed to attach them here?
In my previous post it mentions a few sparks and pieces flying from the balancer area but no noise , but today there is a clicking noise. In the spring what do I look for ? I will take the pulley off but then what ?Here is a link of the noise. This started today last week when I saw the parks yet NO noise , one week later noise WTF..
https://www.youtube.com/watch?v=m4PHSPhr890

 

[stonyloam]

Yes, someone has added an alternator. Originally it had a rotor and stator like an outboard. The voltage regulator probably went out and it is way cheaper to just add an alternator kit. There are magnets glued to the inside of the rotor (what you have been calling the harmonic balancer). I am betting that a magnet ( or several) has come loose and rattling around in there grinding up the stator. You need to pull the rotor off and see. You should be able to pull it off with a puller from the autozone tool loaner program. If the magnets are loose you can remove them, but you should take it to a shop to check the balance. You put it back on using a fine thread 1/2 inch rod a stack of washers and a couple of nuts.

 

[Scott Danforth]

if you pull magnets from the rotor, pull them all.

use a harmonic balancer installation tool (available along with the puller)

 

[stonyloam]

Yeah remove them all. I think to make a conventional instillation tool work you need to make some spacers because the rotor is deeply dished in the center. Seems like I used deep socket for the spacer once.

 

[karayj]

ok that was my call . I have taken many off cars with a puller and yes all the magnets MUST come off for proper balance I'm wondering if that is causing the vibration that makes it feel like a cylinder is not firing when it is . I used to be a car mechanic and learning boats is actually fun. Learning allot here. Hey one thing I heard and not sure if it is true. I was told the 3.7 was a crap engine and nothing but trouble it that true?

 

[Scott Danforth]

. I was told the 3.7 was a crap engine and nothing but trouble it that true?

pretty much.

from a concept point, it was a good idea

from an execution standpoint, it was a disaster.

the only good thing is the HX cooling

its a platypus........ a ford 460 iron head, pistons and rods in a custom mercruiser designed aluminum block with floating bores using a GM flywheel and the rotor from an outboard

because of the floating bores and the aluminum block with the iron head, any slight bit of over-heat and the head gasket goes. this is the primary reason the heat exchanger was added.
because the cam nose was not hardened, the seals wear out the cam nose and the coolant tends to leak into the oil

the block should have had a deck on it and the head should have been alluminum
the cam should have come sleeved from day one.

 

[stonyloam]

Yeah you need to keep on top of the maintenance. Change ,the impeller every other year and watch for coolant leaking out of the engine water pump weep hole. Mercruiser manual #8 is the one you need. When it runs right it is a great engine.

 

[karayj]

Thank you for that information what happens that when I bought the boat I did get manual eight thank God.

I wanna bring up the original matter I have a question for the experts out there I’ve learned so much being on this forum. When I first bought the boat I should’ve change the impala right away because it sat for two years and it basically dry rotted so it worked the first few times I ran the boat but when I took it on the lake my best guess is that it completely went.

The reason I say this is when I started the boat I might’ve drove in it for about 90 seconds at an idol then I gave it 70 per gas for about 45 seconds and she died. The boat restarted a few times but never stayed idle then I had to paddle it my question is is it possible I run the head gasket

i’m wondering this because now she idols as if I’m missing a cylinder and I’m reading that if there is a leak between the two cylinders it’ll give that feeling there’s no milk in the oil which would be water there’s no coolant burning out the back but when it runs it kind of feels like something is definitely off and not smooth like it used to be

 

[Scott Danforth]

without the impeller, there is no raw water flowing

so automatically the flapper and the rubber exhaust hose are now toast. those rubber bits have a maximum temperature of 250 degrees. exhaust with water in it is about 200-220 degrees. exhaust without water in it is over 1000 degrees

with the HX, you have a very short period of time prior to over-heating when you loose raw water flow.

what did the temp gauge read? in that 2-1/2 minutes, you should have looked at your gauges about 10 times.

yes, consider the head gasket suspect at this time.

drain the coolant and do a pressure test on the cooling water jacket.