Is this normal? Steam from exhaust? 4.3 merc.

[65fordguy]

So today while getting ready to winterize my boat, I hooked up the muffs and started er up. . . all was good but the engine started producing steam from the prop and from exhaust... normal water flow out of the engine.. My first thought was Cold water.. 40 degrees out side almost dark out. kinda like breathing in the cold making steam ... i know this because when I exhaled I got steam.. so just wanted to check with you guys to check.. like I said it was getting water flow out of the engine.. warm not hot. seemed to be normal..and only when the engine got up to temp did I see this.. When I ran it earlier in the day outside temp closer to 50 I didnt see this.

I only got worried because for about 20 seconds I started the motor the second time with stinkin water muff ( has a shut off valve on it ) turned to off.. I quickly shut the engine off.. turned on the valve and let water run for a bit.. then started back up.. water started to flow again seconds later. . . and then a few min after that noticed steam. there was initially light light steam.. but I've seen that even in summer..

And the Water impeller was just changed in july.

so Im hoping the fact that I had been running the motor with water and just turning the valve off and not unhooking allowed for water to still be in the hose and unit.. that few seconds. I had one of those Derr you idiot moments.

Forive me Im new.. perhaps steam in the winter is normal. im just paranoid.

Thanks for the help

 

[Don S]

Re: Is this normal? Steam from exhaust? 4.3 merc.

Yes, they do that. IF you had good water flow and nothing overheated, you should be good to go.

 

[ziggy]

Re: Is this normal? Steam from exhaust? 4.3 merc.

don't feel bad. seems like every summer i just gotta forget to turn the water on too. usually give it a 10-20 sec. run before i remember. i've got the pre alpha drive which has a different impeller than you got in it. the aplha1 version impeller i use usually shows very minor wear on it after one season use. i replace it yearly. anyways, 'i think' the alpha1 impeller is pretty darn fragile. let it run 90 sec. w/o water and it'll be trash. 20 sec and it's showing sings of not being happy.

that said. 'i think' the genII impellers are much more desirable. they seem to last considerably longer. i can only assume they will take abuse somewhat better than the alpha1 version also. that said. i think yer gonna be fine. just watch yer temp gauge(my personal favorite gauge). any signs of getting hot. you'll know where to start the inspection at.

the steam would seem normal to me too. makes sense, ya see yer breath. the water is warm coming out of the drive. same as you, makes steam. warm water is the norm for me anytime of the year when running on muffs in the driveway at home. she never comes up to operating temp w/o the lake and load.

 

[65fordguy]

Re: Is this normal? Steam from exhaust? 4.3 merc.

Thanks, it took awhile to get to somewhere around 150 before I cut it off.. didnt let it get to 175. which is half way mark on the gauge. no strange whine or anything. Im feeling better now that you guys think its normal.. I have a guy interested in the boat and may sell it and would hate to have something wrong with it.

As part of the deal .. if it happens.. Im going to require it be taken to a merc service for a winterization and impeller change anyway. Since he cant drive it anywhwere with lakes being down I would feel better about that.

 

[oops!]

Re: Is this normal? Steam from exhaust? 4.3 merc.

the impeller probably got toasted when you started it with the valve off......the motor will still be cool with just the hose pressure but while underway, it wont be able to suck water....

getting it changed is a great idea