zane

last summer my wife and i picked up 20' chris craft stinger with a 454 . motor is all stock with thru hull exhaust. my only concern last year was that the motor steamed when coming off plane. i cant really tell if its steaming while we are up and running. i have good water pressure and the temp never gets above 175. is this a sign that water is leaking back down from the exhaust? i've checked the plugs and none is any cleaner than the rest. friends have told me that i'm noticing the steam now because the exhaust is so close to the helm. its not reversion, because i never fall off plane that quick. any ideas...should i change manifolds just to be safe?

Von Bongo

Likely Normal..do a search for steam and you'll find the discussion.

mats

The steam is most likely the result of too little water flowing through the engine. Likely causes are the impeller or a restriction in the little suction hose in the drive.

ENFORCER24

I Have to agree with mats , low water flow , especially if your running 175 degrees , my 454 runs 145 all day long with it only going to 160 when i really push it hard
how long has it been since the manifolds were replaced , in raw water cooled boats manifolds last anywhere from 3 years and up depending on how you treat them (fresh flush) and where your boating , also look at the thermostat housing , somehave a pair of balls on a rod that can get hung up and heat up one manifold more then the other.
what kinda drive ? how long since you replaced the impellor ?

zane

the drive is bravo 1, and we changed the raw water impellor before we splashed last year. i think its getting enough water. our other boat has twin 454 crusaders, and just by looking at it , this motor appears to have much better flow. i pulled the risers off and from what i could see the manifolds looked ok. its not just one side steaming...they both steam for a few minutes after i come off plane...then it stops. the temp doesnt fluctuate either. i'll pull the thermostat off this weekend...i might even have the wrong size in.

thanks for everyones suggestion....its been quite a few years since i've owned a fast boat....i always ran outboards so i/o's are new to me.

Dock Holiday

That's pretty much normal. Especially this time of year with cool water temps.

East Coast B

Temp is building in engine when running, off plane water flow decreases due to lower rpms turning impeller, so it takes a little longer to cool motor with less water flow..... bit of steam until it cools a bit.... I say normal condition. If it were continuous, then I'd be concerned...

pullmytrigger

are you sure the steam isnt coming off the drive when you dunk it???........does this happen after a fairly long run on plane???.......do you have white chalky deposits on your drives??.......if so you need a drive shower

zane

its not from drive....steam is clearly visible from both exhausts. i'm starting to think this ok from what others have posted

Kidnova

Next time you're out on the lake feel the exhaust on both sides to see if they are too warm, or hot.

Would be a good idea to check the oil cooler to see that there are no obstructions. I pulled mine out last fall and found a thin layer of weed/plant material. Before pulling and checking the oil cooler water seemed to be flowing ok but the port side exhaust was allot warmer to the touch than the starbord side. Yes, there was a little steam after coming off plane, as you describe. Not sure but the crap in the cooler may have had something to do with it ?