Thru-Hull Exhaust Help UPDATED!!!!!!!!!!
 

I took off the silent thunder platform from my formula. I finally got to drive the boat for the first time today with my newly reman motor. I got what seem to be excessive amount of steam or whitish grey smoke coming out the exhauast. Motor ran great and had good oil pressure...45 and good temperature...160 I put on stainless steel tips with built in internal flappers...the mechanic at the marina said the internal flappers could be causeing splashing thus enhancing the steam...I don't get it though. its a 5 minute idle out to the sound it seem ok getting out there with some steambut once I opened it up and looked back I had a trail of white smoke...I brought it back down to idle and putted into the marina while it was still smokeing alot. shut it down for literally 2 minutes well when mechanic started it...nothing minimal...the same amount I had when I first headed out. what gives and whats aceptable? any ideas
-Harry

edit...the motor is a 350 5.7 the boat is a 89 formula206

anyone?

Steam is a fairly sure sign of too little waterflow in the cooling system. It may still be able to cool the engine, there is normally a quite good safety margin.
The low flow may be due to a bad impeller or a restriction somewhere. The most common restrictions are impellerblades in the oilcooler inlet screen or a collapsed suction hose in the drive. I would start checking the easy ones (impeller and lost blades) and save the suction hose for last. It is a PITA to change.

check where the water hose goes through the transom, they seen to get salt built up and collapse the hose . what year boat is it

Formula 18, I had a oil cooler on a engine I once had. Take off the inlet hose, there is a plate w/several holes in it about the dia. of a pencil, one time i sucked up seaweed and blocked it ,keep it simple start w/ water intake and follow it to the end. "HIGH LIFE"

Steam in the exhaust with a cool motor is also a sign of leaking exhaust manifolds. Pull the risers and inspect them for rust holes.

Rene

is it steam or white smoke? white smoke could be the assembly burning off if the motor wasn't dyno'ed...

Water temp in the sound has got to be below 60 degrees...that will make for alot of steam.

thanks guys losts of things to check...
1..I have a new impellar, new circulator pump, new gaskets in the mainfolds and risers.

2. I will check the oil cooler and for some colapsed hoses.

3.
the thermostat is new as well. it has the houseing wiht the check balls. they seam ok!!
I am hoping this is a non issue becuase the motor seems to run very well. The motor was not dynoed. I don't know what there would be to burn off.
It seems like steam but I guess it could be white smoke. Most of it dissapates quickly. I notice that when I first start up...there is no smoke just water. I guess its as the motor gets hot!

i just pulled off the oil cooler and there is not screen..I can see right thru both holes water and oil...I am running 25 40 oil...is there a differnt one I should try, maybe one that would help it run cooler...it does seem to head up toward 180 at idle sometimes.

Where is this screen? I got the idea it was in that cooler that bolts to the engine mount? mine didn't have one..thanks
-Harry

What kind of drive

alpha 1

Does your thermostat housing have the check balls in it? if so, one could be sticking, hurting water flow to the exhaust.

Are the rubber through hull exhaust hoses getting hot after a run, too hot to touch, and feeling soft?

Is most of the steam coming from the right (driver side) exhaust?

Most merc engines has a screen on the inlet to the oilcooler. I guess it is there to stop impeller blades and the like to enter the engine.

The steam is pretty overal. I checked the check balls they move freely but did notice that on one side the metal isn't straight anymore its more like / so the ball never completly seals it. Don't know if that could do anything.
as far as the exhaust rubber. it does get a little bit soft. Sometimes the motor runs up to like 180 I don't know whats going on as everything is nice and clear with a new pump in the drive.

is there a way to check flow at specific problem points?

my motor has the big buliky thermostat housing with the check balls. When I feel those 2 lines they are really cool, but when I feel the bottom 2 they are almost two hot to touch. I am at a loss here "frustration has set in" what will taking the thermostat out do?

Im posting some pictures of my problem after I jsut changed the thermostat housing so what we have is

new impeller
new water pump
new thermostat houseing wiht new check balls

the water temp is perfect at 145 during idle and throttle I can keep my hand on the exhaust water for a few seconds before it gets to hot...what do you think steam or smoke?? first 2 at idle 700 next 2 at 1300

1300

Does not look like enuff water flowing....I would say that it was steam...I would be suspect of the impeller...new or not maybe it did not go back together right....Housing could be scored ...something stupied like the seal around the copper pipe. Also I have had the pipe that goes thru the transom leak. It can corrode. pull up a merc diagram you could see it leaking on the hose with the drive turned to the right.

That definitely looks like steam caused by low water flow. Been there. Since it is both exhaust pipes the problem should be in the section before the water is split up two paths. I am not familiar with the alpha drive but are there any screens, hoses or seals/o-rings down in the drive that can create a problem?

I'll keep checking but its flowing alot of water...its all over the driveway...its shooting out alot

Risers or manifolds. Even in a low flow condition, you won't make that kind of steam in the driveway. The engine has to have some real load before you make steam due to a low flow condition. Obviously, a no flow condition would make some steam, but I did see some water flowing out of the pipes. Check the exhaust before it costs you more than a few gaskets.

Rene

How hot is the water coming out?????? It should be about the same temp as bath water.

yea water is coming out....can I ask this question while it may be dumb...what is the purpose of the water going to the risers...the water goes into the bottom of the manifold than travels all the way up...my question is why can't I squueze off the check balls much tighter, really to force all the water through the motor once it gets hot enought to open the thermostat? Could this be my problem...it seems pretty flat!

also to show I do have water coming out this is a picture before the motor reaches operating temperature.

do you have closed cooling? if so i would look into a bravo belt drive seawater pump.

I wish I did but I do not

You should be able to keep your hand in the exhaust water for as long as you want. It sounds too hot and like it caused by a lack of flow.

From what you say, your engine temp is fine, so look at another area. Check your exhaust. You could have an obstruction inside the risers.

I don't know why i didn't think of this before...could this be it...when I got a new water pump pulley they told me that they upgraded it and the pully is bigger...they gave me new belts. now wouldn't that slow down the pump and cause less water to flow to the motor making hotter...hence have more cool going to the riser?????? CAUASING STEAM!

Bigger Pulley = Slower shaft speed at the pump = lower volume (all other things being equal). If the pulley was made for the pump (i.e. not mismatched), the volume should be ok. The part number of the pump must be specific to your motor - especially if it is aftermarket. Did you check the pump in the drive? If not, you should crack it open and inspect. Make sure the vanes are intact and inserted the right way.

I have a Formula F223 with a 454 Mag Allpha, and the only time I have steam (low quantities) is when I initially fire up the engine when its cold. After it gets up to temp, I have no more steam.

-Larry

I think thats what it is...the pump is from one place and the pulley is from another....I need get my hands on the smaller pully like I orginally had on the motor! I bet that helps.

Pump in drive is brand new

ttt- What was the outcome on the steam?