Smoke or Steam

[NautiqueNutt]

My 1999 GT40 has about 675 hours on it. I change the oil regularly and it always looks fine, not milky. I usually see a vapor or white smoke coming out of the exhaust while cruising at any speed. Some time at idle. How do I tell if this is just steam or is white smoke. I can sometimes smell exhaust fumes while boarding, so I was wondering if maybe all of the gas is not burning off cleanly. I have checked the flame arrestor and it is really dirty. I am going to clean this asap and see if it makes a difference. Any other suggestions?

[surroundsound64]

RE: Smoke or Steam

Well... if it's steam it will disappear after a few seconds. Also, if it were smoke you should be able to smell it. It is normal to smell gas, as most carburated engines are set rich, and should be in order to help cool the engine. It's fine to smell gas, as long as you're not getting black stuff all over everything.

The dirty flame arrestor might signify an exhaust leak. As has been said in other topics here lately, steam is very normal. You have hot gasses mixed with hot water coming out of the boat mixing with cool air and cool lake water. Something is going to evaporate.

[DavidF]

RE: Smoke or Steam

FWIW:

Water: white smoke (steam)
Oil: blue smoke
Fuel: black smoke

[NautiqueNutt]

that makes me feel better since it is white and disappears. This is an EFI, not carb. FYI. Thanks