white smoke 4 stroke?
 

Now i know white smoke means a bad oil mix in a two stroke but what does it mean in a 4 stroke? The motor ran great, no hiccups, stalling or sluggishness, just a bit more white smoke than Im used to seeing. Its only my second time out for the season, didnt notice it the first time

could it be the fogging burning off?

if you didn't smell anything, maybe it's not smoke, just vapor?

white smoke- water in cylinders?

i could only smell it when i put my hand over the exhaust.

water in cylinders? would that burn off after an hour or so?

Sounds like a blown head gasket. A small leak will allow seawater to enter the cylinder, when it hits the hot gases it vaporizes and you see steam. If is was some winterizing oil it would burn off in a couple minutes. Most 4-strokes don't have any visible smoke if they are running normally. A steady stream of white smoke is water vapor and is probably a head gasket....or a cracked block...lets hope it is not that. Somehow water is getting in there. Pull out the plugs when the engine is hot and inspect the plugs. You may see tiny water droplets on the hot plug bead-ding up.
It may still run OK even with a little water getting in there, esp on multi-cylinder engines. A lot of water (serious leak) will cause misfiring. It probably will not heal itself.

white smoke
 

Mr Hunters, Was this today? A engine will produce white smoke when the exhaust out the relief port is warmer then the ambient air. On a day such as today with east or northeast winds and high humidity this will happen [B]Normally

Mike

Well said wrench - that's what my pea brain was trying to put to words.

Smoke colors
White=water
Blue=oil
Black=fuel

I think it's like Wrench said though. If you have a blown head gasket, the motor would most likely be skipping and overheating..Water don't burn well..:laugha:

Check the plugs
 

If its a head gasket check all the plugs, chances are one (the one with the leak) will look like it was steam cleaned compaired to the others.

I have a zuki 70 HP 4 stroke and it only smokes after I winterize her...best of luck.

Monty

well, thanks for the heart attack sandman... :)
just when I thought I was in the clear you go ahead and tell me i might have a cracked block!!!

It was on Sunday water temp was reading almost 70 in the river and air temp seemed alot less... humidity was also high... so im hoping that it is that simple. I was trying to convince myself of that while OTW but was still a bit uneasy with the whole thing.

Ill run it in the yard this week and see what i see.

yikes! its still under warrenty though right? check your pms.

I suppose it could be humidity it will not persist day after day. Try it on a different day, if you see constant steam or "white smoke" (esp at idle)...you have water in the cylinder. Pull the plugs to confirm. You will see the culprit cylinder. If they all look exactly the same then you probably don't have water in there. If one looks a lot different or has water on it, that is the problem. Generally, if it is humidity is only lasts a short while until the conditions change a little then clears up.


I didn't mean to freak you out with the cracked block, its rare but it can cause water vapor in the exhaust. If it happened right after winter storage and the engine was not winterized properly then it is a greater possibility.

My bet would be if it is not the humidity and it persists for more then one day you have a leak in a gasket. ( I had a 40 hp that had this problem, it ran fine with a small head gasket leak but steam was seen in the exhaust)

If this is under warrenty, bring it back pronto and let them deal with it.

thats cool.. better be safe than sorry.

if the rain lets up for a minute tonight ill run it on some muffs and see.

what a pain... only 27 hrs on motor.
hopefully all is ok.

well the tech at the marina thinks it's vapor (without bringing it there) but if continues, then bring it in. didn't sound overly concerned since it was running fine.

havent had a chance to run it in the yard... the weather has been very vaporous ;)

once again I must post this link.

http://www.youtube.com/watch?v=nrnU2nDj_Yk

well, i can't view that link until this evening but im sure its not something on how smooth motors run all the time ;)

I have a Yama 90 4 stroke and see a little vapor but only when there is a temperature difference greater than the differential of the co-efficient of the air minus the humidity times the wind direction.

Translation:
Don't worry about it if the motor is running good! Clammer taught me these words of wisdom. When I first got my boat I worried about every little thing.

i got half way through saying to myself, is this guy serious?? :tooth::tooth::tooth:

good advice my friend.

put the muffs on last night before the thunderstorms hit.... not a puff of smoke :) all is well for the moment.. now time to get some fish!

thanks for all your input guys... sometimes you just never know.

-shaun