Engine Hard To Turn Over

PickleRick

Dont expect water to show up on the dip stick. It will be sitting at the bottom of the pan.  If you pull the drain plug the milky grey mixture will be the first to come out. 

YYZRC

Details on the magnet please!!

YYZRC

Can you snap a pic of the exhaust flaps?  I've never seen them.

aero3113

@YYZRC I did but they are hard to make out.

aero3113

I’ll do a separate topic on the magnet.

YYZRC

Looks like an endoscope in a butt hole. 

aero3113

So where would the water be coming from in the manifold? By looking at it you can’t really see anything out of the norm.

Willhound

aero3113 said:

I’ll do a separate topic on the magnet.

Sorry to see you have to change all those parts but happy you found the issue before major damage. I just happened to start a "Neat Gear" thread for the magnet.

PickleRick

You can fill the riser and manifold with acetone once dried.  If it will weep anyting it will weep acetone. 

If the flapper. Is bad replace it while in there. 

aero3113

Yea, will definitely replace the flapper.

PickleRick

Also acetone is cheapest at Wal-Mart but they only allow 1 or two gallons per person at a time.

212rowboat

aero3113 said:

So where would the water be coming from in the manifold? By looking at it you can’t really see anything out of the norm.

i'm going to have a heck of a time trying to explain this... but it's what happens most often...

your exhaust manifold is a pipe in a pipe.. the exhaust goes through the pipe that butts up to the head port, and that pipe is submerged in a pipe that has water circulating in it. 

wet joint: the water jacket extends into the risers
dry joint: the water goes through an external hose to the risers, on the front side, poking out of the manifold, bending 90*, and into the riser.

but those likely aren't the issue you're facing... usually by the time either of those fail, there has been signs galore- to include external rust at the marrying surfaces... the place failures like to happen, especially early is:

the elbow is also a pipe in a pipe...  the 'external' pipe is wet.  here, i found an image showing dry joint plumbing and passages: 


right at 10 o'clock is the end of the elbow, which has a boot over it right up to the little bend on top and bottom.. that water is injected into the exhaust stream... it cools it.. 

if one of those ports are closed due to corrosion, the water still has to go somewhere- and it goes through a non-clogged port... but at a volume the system isn't designed for.  this is why your elbows get wicket hot when they're beginning to fail- it isn't getting water injection around the full circumference of the exhaust.... now the water which is going to another port and being spit into the exhaust stream is overwhelming that port and pooling + streaming... which is fine.... most the time... until the engine stops... and then some of it drips back into the exhaust port and the rest sinks back into the elbow and riser.. 

we're not talking a tremendous amount of water- at first.  it's usually just enough to stress your starter- which (again i offer) is the #1 indicator of a weak battery or water ingestion. 

I'm glad you paid attention to what your boat was trying to tell you, @aero3113 , most folks wouldn't... and then those folks would be forking over some serious dough to get fixed back up and cursing the maker of the boat or mercruiser the whole time...

also note:  flappers are overrated.  i don't run them because they fall apart and clog things, and cause issues more than they are worth... HOWEVER- i trailer the boat and don't dock it but for short periods- i never place the stern in the way of wakes, waves, or even tides... i don't have exhaust bellows, either- i run a tube... when in circumstances that allow i run the drive all the way down making rising water hard to negotiate the path to the engine... basically, i think the flaps are a band-aid.  it's my personal opinion only, and i wouldn't recommend anyone follow my lead on that or to do so at your own risk. 

aero3113

Thanks @212rowboat , I hope no damage was done. Like I said, when it started it sounded perfect and smooth.

212rowboat

aero3113 said:

Thanks @212rowboat , I hope no damage was done. Like I said, when it started it sounded perfect and smooth.

i doubt there is... i'd be surprised if there was... you caught it early... you listened to what your boat told you and how it complains... that's the lesson here by my reckoning. 

aero3113

Here are a couple of pics of the water that was sitting by the valves.

aero3113

Started to take the fittings off, was definitely starting to plug up also. Should I use Teflon tape or thread sealant on the fittings that are going back on?

Pat310

I also have raw water cooled engines in salt water like @aero3113 . I’ve  looked for flush kits for them but most I’ve found are home made c**p. Anyone install them on their boats?  Would love something I can connect salt away also.  Just want to prolong life of manifolds and risers

aero3113

I see it calls for Perfect Seal on the riser gaskets, is Permitex Aviation gasket sealer ok or should I go with Perfect Seal?

aero3113

I was looking through my pictures and noticed that the gasket with the restrictor hole was installed on the exhaust manifold if you have a spacer it should be installed on top of the spacer. See link

https://www.perfprotech.com/blog/boat-and-engine-technical-tips/marine-exhaust-systems/mercruiser-exhaust-systems-position-of-the-restrictor-gasket-versus-full-flow

aero3113

Good video to watch for install instructions.

https://youtu.be/3ChXrMNVexY

PickleRick

I used pemrmatex right stuff.

Its my go to.  But in also took a **** file to all mating surfaces before install.  It's amazing how far oem manifolds were off.  I only used a very thin coat.  I had wet joints.

212rowboat

Pat310 said:

I also have raw water cooled engines in salt water like @aero3113 . I’ve  looked for flush kits for them but most I’ve found are home made c**p. Anyone install them on their boats?  Would love something I can connect salt away also.  Just want to prolong life of manifolds and risers

https://www.iboats.com/shop/perko-flush-pro-valve-kit-1.html?gclid=Cj0KCQjwsuP5BRCoARIsAPtX_wF4udIIGoy_TsPzDWUVkpxh0P13eWofb9CA3gtuH6EMH5PP5QrnqsgaAss8EALw_wcB

simple stern flush kit... the hardware mounts somewhere unobtrusive on your stern, and the hose T's into your plumbing AFTER the sea pump (or in case of outdrive pump, wherever- mine intercepts the incoming flow right after the steering cooler)... now remember, you need that impeller in either your OD foot or the sea pump in water so as not to burn it up... so.... implement a valve that redirects the sea pump through the bilge waste pump, and uses the stern flush as the supply to the engine.  

two caveats:

• for the love of all that's holy, don't forget to swap the valve back before you take your boat out..
• don't ever pump water when your engine isn't running.  this is precisely how i flooded my engine. 

you can also use this to inject 'salt away' if you so wish. 

or......

you can invest in ceramic coated exhaust manifolds, risers, and elbows.  your problems are a thing of the past.... they're a bit pricey, though. 

honestly though? just go with it as is... they're good for four to five years.  

I know a guy who passed away a few weeks ago- i made a thread about it here- who was a master boat mechanic... he serviced commercial vessels, too... he literally tapped a manifold and installed a galvanized bolt.  he would pull that bolt once or twice a year and inspect it.  he said "the manifolds last two bolts, the risers one and a half" and grinned... that's pretty slick, no?  he made a sacrificial indicator... the size of the bolt, IIRC, was 5/8" head and 1/2" shaft, standard machine threaded.  

212rowboat

PickleRick said:

I used pemrmatex right stuff.

Its my go to.  But in also took a **** file to all mating surfaces before install.  It's amazing how far oem manifolds were off.  I only used a very thin coat.  I had wet joints.

yeah, i've never seen a single set that didn't need to be touched up with a file.. a few passes is all that is really needed.  they're super sloppy on both the manifold, the riser (spacer, if you're using them) and elbow... i was warned, no, straight up told NOT to use any type of RTV on the surface when i went to closed loop cooling, but i did anyway... i was a bit perplexed how 'high and mighty' mercruiser engineers could say such a thing when i was looking at the OE products they produced (the terribly uneven marrying surface) and keep a straight face.  we're not talking slobbing it one, just a nice even and lean film... 

Ian

YYZRC said:

Looks like an endoscope in a butt hole. 

If this looks like your butthole you better see the doc again...

aero3113

I got everything back today and all is good! I didn’t have enough time to do an oil change, planning on getting that done tomorrow. @PickleRick your threaded rods really made the job go smoothly, plenty of room between the engines to use them. @YYZRC I took a better pic of the flappers for you also. The first pic of them is with the half missing and the second is with the new one installed.

PickleRick

You work quick. I'm glad they helped.  

aero3113

By the way, it’s a pleasure to install new spark plugs with the manifolds out of the way!! 😎

aero3113

@PickleRick , I hate knowing that something is as it shouldn’t be. If I have the time it’s my first priority. I’m a bit anal that way, LoL.

Liberty44140

aero3113 said:

By the way, it’s a pleasure to install new spark plugs with the manifolds out of the way!! 😎

Lol when I saw that pic earlier of the plugs I was thinking boy I’d change the plugs now with all that wonderful room!

PickleRick

aero3113 said:

@PickleRick , I hate knowing if something isn’t as it shouldn’t be. If I have the time it’s my first priority. I’m a bit anal that way, LoL.

We hadn't noticed 😂