[newbie]

new boat has an 89' merc 470, with a FWC system. while running today, engine overheated since i wasent paying attention to my guages

boat overheated pretty **** bad, smoking to holy **** and spewing anti0freeze to the bilge. if you were in jones this morning, i was the idiot with the smoke pouring from my engine, and doing the tow-of-shame back home.

ive ran the boat 4x prior to this, and quite hard in thursdays weather with no issue. only difference is today, since i left on dead low tide, i only have about 3.3ft in my canal, and i got a bit too close to the edge and was kicking up some nasty black muck. (had no choice, was a bulk-head barge parked in canal)

im assuming i have some sort of restriction of water flow somewhere now? but where do i start looking, and could me kicking up muck have caused it?? i would think so since i had no issues prior to this running the engine in water, or out with ears.

 

[Fishbust]

wow...

The soft black mud is usually harmless to the water pump impellor, hard to avoid on the south shore in creeks 100% and most of it is just the result of prop turbulance and not getting sucked in if you are careful and taking your time. A little bit sucked in will flush right through and out the system.

But you must have done a "real good job" to overheat like that. A little overheating and I would say to just check and trace out the normal flow path of the cooling water and it is easy to find the problem.

I gotta tell ya the anti freeze in the bilge does not give me a warm fuzzy feeling. You hurt it. Gonna cost ya. Your own fault.

You go through a lot of boats.

Next time tilt up as high as you can without causing undue/unwelcome vibration from the u-joints and just pop it in and out of gear intermittently to keep moving forward. You won't suck up so much sand/mud this way. And then WATCH YOUR GAUGES and make sure everything is all right when you know you were in very shallow water and kicking up mud.

 

[newbie]

hey, i dont go through alot of boats. this is only the second one to make it to the water, 1st one still puts around

my issues are always rather stupid too, usually stemming form lack of knowledge/experience. happened to the best of ya at one point. good thing i have extremely helpful people like you on nor'east......

is it possible either just fried the thermostat, or impeller? the engine starts and runs normal again, just as i said, the temp climbs slowly, and i shut her down again at 200, which is a bit over normal for the boat. so its got to be taking in some sea-water for heat exchange, right?

it dident spew all the anti-freeze out, as i still have 3/4 of my reserve left. it had come out of the pressure cap as best as i could tell. hoping it may be something minor, and i can chalk it up a lesson.

i can assure ill be investing $$ into an engine alarm just incase it starts to overheat again, as its hard to remember to check guages in the heat of chasing birds down

 

[MakoMike]

Start at the sea **** and work your way through the engine all the way to the risers. Could be anything, but most probably the risers. Hope you didn't warp the head.

 

[newbie]

ok, problem is, what am i looking for??

almost 500 posts later, ya should remember me as being mechanically illiterate by now mike

i try and learn to fix my boat through posts on nor'east

 

[ReelTime]

Toasty Merkruzer / Fish Smoker

I go through a lot of engines!!!

I think yours is a 6 cylinder I/O ?

I would take off the outdrive and clean out the cooling passages and replace the water pump or at least the impeller, I am not sure if you have a replaceable plastic impeller housing. $50 kit?

I would clean out all parts of where salt water goes through. I think you said you are fresh water cooled, so your block should not be affected by the uptake of crud. Disconnect all the hoses and drain plugs and maybe replace any pencil zincs (just because everything will be apart). Basically chase all the passages where salt water goes and make sure the sediment is gone.

Manifolds? I don't think they will be a problem unless the boat always overheated under a load at speed.

Now that your salt water stuff is clean, probably a good time to flush the motor and put new water/antifreeze miture.

So much for the cooling system pennance.

Now for the motor - note the stuff that comes out of the salt water passages, is garbage even coming out?

Note the coolant that you change in the motor ... is there any oil in there? Let's hope not. Bad head gasket.

Change your spark plugs. Run the motor, go for a ride. Take them out if stuff feels wierd, do any of the plugs look different? Is one really clean? Let's hope not, Bad head gasket.

Probably better to do up front... do a compression test.
I was wondering how come one of my motors was running badly... I 'did everything' ... then I did a compression test, one cylinder, no compression at all. Dang!! Motor number one!

If you have oil in the coolant, or coolant in the oil, a really different looking spark plug from the others and or low or no compression in a cylinder or two, a head gasket needs replacing, and possibly a head needs to be machined straight. Just exchange the head(s) at that point for a rebuilt one ($150 plus gaskets?).

I am doing motor number two this year (the other side), why not, I now know where all the bodies are buried with the job!

A good source for hard engine parts (heads, blocks, etc) is Rapid O Marine in Florida. www.rapidomarine.com

Good Luck,

vk

 

[MakoMike]

newbie wrote:
ok, problem is, what am i looking for??

almost 500 posts later, ya should remember me as being mechanically illiterate by now mike

i try and learn to fix my boat through posts on nor'east

Hey this is pretty simple stuff.

Just take off each piece that the raw water runs through and make sure that water will run through it. If everything on the raw water side is O.K. then do the same thing on the antifreeze side. Something has to be clogged up and preventing your colling system from working properly. I'd bet its on the raw water side. Also check the impeller in the water pump, it may not have caused the problem but it may have burnt up when you overheated.

 

[Cmonsters]

exactly what Makomike said. I have the Mercruiser 170 which is basically the same as the 470. Its a 4 cyl. Go the easy route first by pulling the hoses off at various points of the raw water routes (I believe 1st being water cooled voltage regulator if you still have one- or at in side of the heat exchanger.) You might want to pull the hose at the LAST place first and then backtrack- that would be the hose coming up to the exhaust elbow- It should shoot out of there like no tommorow! I THOUGHT I had a clog problem myself last year...turned out to the small length of hose connecting the bell housing to the thru stern (outside the boat) the hose apparently kinked from softening over time and waterflow was RESTRICTED. This probably isnt your problem but im thinking it is possible if you have a slight kink in that hose a good dose of mud could have clogged up your whole flow there...too. Bottom line is if you have bad raw water flow showing up at your first spot (either voltage reg OR inflow to heat exchanger) then the culprit is either a kinked/mud clogged stern housing hose- OR the impeller in the drive.

 

[newbie]

now just need to figure out how to short haul the boat to go through everything and print up the pages of posts from here

i checked the oil, and anti-freeze in the engine, and everything looked normal THANK GOD. so hopefully thats a good sign?

 

[ReelTime]

Don't know til you go

Those are good signs. Clean out the saltwater passageways, do the impeller and see how it goes.

vk

 

[OceanChaser]

Boat=Break Out Another Thousand.

Buying a boat can be like playing russian rulette.

Good luck...I really feel for you now.

Want to buy an aquasport...you have fished on it before

 

[Cmonsters]

???

Hey Newbie, how did you make out? Inquiring minds want to know

 

[newbie]

no **** money to have the boat short hauled to check everything out, and no one i know has a trailer to haul for a few hours. so we're sitting dead in the water wasting my $1600 dock fee and not catching fish

oceanchaser....ive fished on an aquasport before?? dont remember ever fishing on one......stripers, blackfins, bayliners, grady, trophy, cruisers, angler, wellcraft and formula are about all the models ive fished on

i surely cant be that burnt to not remember a boat i manage to remember all those

 

[Bigkeepers]

My friend did the same thing with his Wellcraft, same motor. He likes to dredge the bottom too. He ended up packing his riser with crushed shells and sand, some small pebbles too. The heat exchanger was piping hot, hoses and all which told us at least it was working properly, but it wasn't exchanging the heat with the saltwater coming in. We pulled the outgoing hose off the riser at the back where it meets up near the rubber boot as the exhaust comes out. It connects the exchanger with the back of the riser. Stuck a garden hose in there, real quick started the engine and turned on the water. The pressure built up immediately because there was crap packed in there. He pulled the riser off and you could see the stuff inside the exhaust part where the water meets to exit the engine. He worked at it with a small hanger a lot of water and I think a real thin knife. He cleaned it out, put it back together with new gaskets and such. It works fine now. He had cleaned out a beach's worth of sand and stuff from his heat exchanger but did not realize that what was sucked in would also try to be forced out. It jammed up at the exhaust end of the riser. You'll see what I mean when you get the riser off. You'll see the inside collar that exhaust comes out and around that is the passage that water exits from. That small space was jammed with grit.

 

[newbie]

all this because they have a barge docked in the canal, taking up 75% of it.

there should be a law about parking a **** 15' wide barge, in a 25' wide canal. i literally had 2 feet on both sides and i only got an 8' beam, and thank god there were no pilings, especially old and submerged, up that part of the canal

 

[OceanChaser]

newbie wrote:
no **** money to have the boat short hauled to check everything out, and no one i know has a trailer to haul for a few hours. so we're sitting dead in the water wasting my $1600 dock fee and not catching fish

oceanchaser....ive fished on an aquasport before?? dont remember ever fishing on one......stripers, blackfins, bayliners, grady, trophy, cruisers, angler, wellcraft and formula are about all the models ive fished on

i surely cant be that burnt to not remember a boat i manage to remember all those

Burnt is OK. I think we may have even smoked a few J's

Come on...offshore in a 24 ft aquasport heading into tight 4 to 5's

Seriously though...we fished last year in 1 to 2's and caught Blue sharks all day long.
Must admit...4to5's is a bit much.
I used to log on as a diffenrent username.

 

[newbie]

OceanChaser wrote:
newbie wrote:
no **** money to have the boat short hauled to check everything out, and no one i know has a trailer to haul for a few hours. so we're sitting dead in the water wasting my $1600 dock fee and not catching fish

oceanchaser....ive fished on an aquasport before?? dont remember ever fishing on one......stripers, blackfins, bayliners, grady, trophy, cruisers, angler, wellcraft and formula are about all the models ive fished on

i surely cant be that burnt to not remember a boat i manage to remember all those

Burnt is OK. I think we may have even smoked a few J's

Come on...offshore in a 24 ft aquasport heading into tight 4 to 5's

Seriously though...we fished last year in 1 to 2's and caught Blue sharks all day long.
Must admit...4to5's is a bit much.
I used to log on as a diffenrent username.

gotcha now. thought that was a striper, but ok lol.

job just gave me a raise, so hopefully i can get boat pulled within 2 weeks. 2 more **** weeks, no boat

 

[Cmonsters]

Newbie, You don't need to short haul the boat to do most of the stuff we are talking about. Only if the tests point to a pump (in the drive) would you have to haul it... but you won't know till you check the other stuff. The clogged riser is a very good possibility... pull off that hose that feeds raw water from the heat exchanger up to the exhaust riser and start her up for just a second or two...should shoot water out of the hose pretty good! if it does youre looking at a clogged riser which you dont need to haul the boat for.... comon fishin"s been great youre missing out!

 

[newbie]

Cmonsters wrote:
Newbie, You don't need to short haul the boat to do most of the stuff we are talking about. Only if the tests point to a pump (in the drive) would you have to haul it... but you won't know till you check the other stuff. The clogged riser is a very good possibility... pull off that hose that feeds raw water from the heat exchanger up to the exhaust riser and start her up for just a second or two...should shoot water out of the hose pretty good! if it does youre looking at a clogged riser which you dont need to haul the boat for.... comon fishin"s been great youre missing out!

i was under the impression she needs to be out of the water for me to do this. once again, shows just how much i know about boats. thank god i can almost fish atleast

 

[Cmonsters]

Bump

Hey Newbie ever get this straightened out? Just curious- I have a vested interest because I have the same engine and was wondering if it was something I hadnt already thought of...