OUCH, that's hot! (pics now added, look)

[emoney]

So, following a wise man's advice, I decided to run my newly acquired '83 Chrysler 50hp (507H3D) to blow out the carbon and to do a shakedown. Before I could get her off the trailer, I wanted to check the tube from the
thermostat to make sure there was water there (no telltale, YET) as I was
in the process of warming up.

Engine had been running maybe 5 minutes, probably 3-4, and when I went
around to check, put my hand on the cyclinder head and yikes, it was h-o-t!!
Like, 2 seconds to burn type hot. I'm assuming the thing is overheating,
am I being paranoid? I've ordered a water pump kit with a new impeller.
I'm in Florida, and I know this has been a salt water motor so I assumed
an impeller was due. Just want to make sure that these things aren't
normally supposed to be that hot to touch.

 

[roscoe]

Re: OUCH, that's hot!

Re: OUCH, that's hot!

Should be able to put your hand on the head for 4-5 seconds.
So I would wait for the impeller to tale it out.
Throw in a new thermostat too.

 

[wickware]

Re: OUCH, that's hot!

Re: OUCH, that's hot!

emoney, Did you have a good water flow during you barrel test and other lake tests? If so, want your chemicals make it run hotter than normal? Plus, do you have a working over-heating indicator? JOW

 

[jerryjerry05]

Re: OUCH, that's hot!

Re: OUCH, that's hot!

Too hot to touch!! Then it probably needs the impeller.When you disasemble look for salt blockage.If the old owner didn't flush.It could be blocked.
Fill out the profile,someone might be close to you.
Put in a teltale too.J

 

[emoney]

Re: OUCH, that's hot!

Re: OUCH, that's hot!

Ok, got the fitting for the telltale. Finally got the thermostat cover off and the thermostat itself probably hasn't worked in a long, long time. There is a lot of corrosion inside that housing and the piece itself is a nasty mess. I started to take off the lower unit, but I'm having trouble getting it all the way off. I'm going to "reread" the impeller change thread. All the bolts are out and it's being held on by the shaft itself.

Just from what I can see, the top of the water pump looks relatively new. I've got this sneaky suspicion that po knew there was a water issue and replaced water pump & impeller, however, never considered the thermostat itself. Although, in the therm housing, it doesn't look like there's been any water in there for a little while. I'm not exaggerating; it looks like something that's been sitting on the ocean floor for a couple of years in there. Is that really, really bad news?

Wickware, I never really got that far in the barrell test because I kept having this suspicion it was getting too hot. When I touched the head and felt that heat, I decided no more running until I knew for a fact. There was moisture in the tube coming from the thermostat, but no real water (does that make sense?). And, no, there's no type of overheating sensor, buzzer, anything of that sort.

Man, I wish I knew a lot more than I do. I'll update the profile, but ftr, I'm in Hudson, Florida.

 

[wickware]

Re: OUCH, that's hot!

Re: OUCH, that's hot!

Emoney, Take your time! Another great finds, but with the salt water issues, you might have some real surprises yet. JOW

 

[wickware]

Re: OUCH, that's hot!

Re: OUCH, that's hot!

Oops! Double check for the over-heating sensor in the head with an ?orange wire connected?. That will set off my horn in my case or buzzer etc due to it working as a ground with a hot source from the switch. Man! With your energy, I would have caught some fish or be on the moon. JOW

 

[emoney]

Re: OUCH, that's hot!

Re: OUCH, that's hot!

Wickware, would it surprise you to know that I have 2 jobs, front 2 different bands, and this is my 2nd boat (her big sister is a sailboat)?
My wife says I'm both OCD and ADD. Hey, I'm 45, they didn't test me back when I was a kid, so you can't technically hold that against me.

Ok, here's pics of the thermostat, housing, and the yuck inside. Take a look (hopefully they come out) and see what you think.

 

[Frank Acampora]

Re: OUCH, that's hot! (pics now added, look)

That's the "old style" head, although they did use it on some later engines. Water comes from the exhaust chest through the clear plastic tube and into the head. The thermostat controls the amount of water going down the tube cast into the head--that's right, the only cooling the head gets is from that cast in tube. Poor design but cheap to make. That's why they used it on some later engines. Newer Force engines got rid of the clear tube and put a plate over the head. Water flow is from the cylinder cooling jacket through the thermostat and down the head.

Your thermostat is shot and I don't think cleaning it will help. It just looks too bent to properly function. SO: While you ask Franz at franzmarine.com to please sell you another thermostat and gasket, run the engine without one--won't hurt it.

The white crap is corrosion and most will scrape out but rest assured, if that was a salt water engine, the rest of the water passages will look the same. I see you have snapped one of the mounting bolts for the thermostat cover. Soak it for a while in PB or WD. Then heat the aluminum with a propane torch. Grab the bolt with a vice grip and work it out while hot. Do not try to remove the exhaust cover unless you absolutely must because most likely you will snap a couple of bolts there too.

 

[emoney]

Re: OUCH, that's hot! (pics now added, look)

Thanks so much, Frank. So I'll still tear into the water pump (I've already
got the new impeller & gaskets) and replace that. It's ok then to run it
without a thermostat while I'm waiting for it? If so, same goes for the gasket for the thermostat housing?

Lastly, is there anything else I should check prior to putting her on the water and opening her up? Shining a pen light into the cylinder heads where I removed the spark plugs, looks like a lot of 'black gunk' (carbon?) in the
lower cylinder. I would guess that's why there's not as much compression on that one? (100lbs dead on, while top is 130) Will that 'blow out' like I'm
thinking or should I try something else. I ran the motor hooked up to the
"Seafoam in a gallon of gas" for those 3-4minutes. There was already quite a bit of black junk getting thrown around, but I've since reconnected to the regular fuel tank.

I've pulled the plugs and cleaned them. I'll try and finish the impeller tonight, is there anything else I'm missing?

 

[tater76]

Re: OUCH, that's hot! (pics now added, look)

This may be a stupid question, but you said you were running it 4 or 5 mins before it left the trailer. Does that mean you ran it out of the water for 4-5mins? if so fixing that water pump may be futile. I wouldnt be surprised if the head has some damage.

 

[foodfisher]

Re: OUCH, that's hot! (pics now added, look)

Thanks so much, Frank. So I'll still tear into the water pump (I've already
got the new impeller & gaskets) and replace that. It's ok then to run it
without a thermostat while I'm waiting for it? If so, same goes for the gasket for the thermostat housing?

Lastly, is there anything else I should check prior to putting her on the water and opening her up? Shining a pen light into the cylinder heads where I removed the spark plugs, looks like a lot of 'black gunk' (carbon?) in the
lower cylinder. I would guess that's why there's not as much compression on that one? (100lbs dead on, while top is 130) Will that 'blow out' like I'm
thinking or should I try something else. I ran the motor hooked up to the
"Seafoam in a gallon of gas" for those 3-4minutes. There was already quite a bit of black junk getting thrown around, but I've since reconnected to the regular fuel tank.

I've pulled the plugs and cleaned them. I'll try and finish the impeller tonight, is there anything else I'm missing?

Complete decarb per sticky.

 

[emoney]

Re: OUCH, that's hot! (pics now added, look)

No, Tater, it never left the trailer. As soon as I felt the heat, it got shut off.

The decarb process can't be completed until I rectifiy the overheating situation. Decarb won't make the water pump, pump will it?

I've added a comment to the "Impeller Change" sticky, I'm a little stuck with
the cotter pin in removing the lower unit. I mean, I've got the actual cotter out put the 'pin' won't budge. Am I missing something or this just another
'stuck thing'?

 

[emoney]

Re: OUCH, that's hot! (pics now added, look)

UPDATE:

In case anybody is watching this thead, there's an update. I came across
another 50hp that has a bad lower unit. After doing a compression check
and looking it over, I bought it for $140.00. I figure the parts like 'starter,
coils, pistons, head, electronics', etc. would be a good thing to have spares
of. The motor is a lot cleaner than what I have so I'm having the lower
unit moved from my engine to this one and then putting this on the boat.

Notice I said, "having...it moved", as opposed to doing it myself. I also found
a neighboring Marine Mechanic/Boat Yard (looking for a fuel tank for the
sailboat) who has very little work that proffered a very reasonable price
to do the work and since I'm so new at this maintenance/repair thing, I
feel a little more secure having him do it.

Now, having said all that, I will also be left with, basically, another complete
engine that I thought I would do a complete tear down of. I've found
gasket kits online for $50.00, so what can it hurt to loosen every bolt on it
and get to the nitty gritty. I figure this would be a great learning opportunity
(I'm determined to learn this) and at the end, I may have two fully
operating engines, sell one, and keep the 'newest/best' one for myself.
If I do get that motivated (and probably will because I go nuts when there's
no projects), then I thought I would start a "Newby does a rebuild" thread
complete with pics. Thoughts?

 

[jerryjerry05]

Re: OUCH, that's hot! (pics now added, look)

I learn from everything I do and some of what YOU do.
Yea post some pics and tell us how it goes.J