Honda 50hp 4 stroke smoking question

[Luvinlakelife]

Hello everyone, let me start by saying it is a pleasure to be here and thank anyone in advance that may have some incite into an issue that came up while we were on the lake today. I recently purchased a pontoon w/ a 50 hp 4 stroke Honda outboard for my family. It was used Pontoon and motor, they are both a 2011 model. We have used it extensively this year and it really runs great I have had no problems and cannot say enough good things about it. Today while grilling out on a beach w/ the wife and children clouds come up and before we can get home the bottom falls out so when we go under a large bridge I decided to stop in the dry and wait out the rain. The engine was in neutral running while I was looking through the storage for the anchor, when I get the anchor out I go to cut the engine and I see smoke coming from the rear of the pontoon. I immediately kill the engine drop anchor and we waited til the rain passed over. Now this was not thick smoke and did not have an odor however it was clearly visible to everyone aboard. It worried me because I have never had this happen, this engine does not smoke, all the gauges read fine, it runs on non ethanol fuel, after the rain passed we continued home and there was no smoke. I have considered; was it due to the vessel sitting still running but the engine was down and I have idled around the dock at the house for far longer before without this occurring, could it have to do with rain being on the engine cover but even after a run across the lake the cover does not become uncomfortably warm to the touch so I do not think it could have been a steam effect. Is this something I should have the marina look at? Is there any reason for a 4 stoke to do this I am overlooking? Thanks again for your time and help.

 

[chawk_man]

Are you absolutely sure it was smoke and not steam? It is not unusual for any outboard to produce some steam that does not dissipate quickly in still, highly saturated air. If it was smoke, it should have had a distinct smell, like burned oil, or burned gasoline, or a burned electrical appliance.

 

[jgmo]

I think it may have indeed been steam. What color was it? I'm guessing you have an extended shaft outboard because of the pontoon. The exhaust pipe is bolted to the bottom of the oil case and extends down into the extension case. If rain somehow seeped into the extension and gotten on or near the pipe then it could have just been vaporizing off and finding its way out through whatever openings there are back there.
But, if I'm wrong, please send me a nickle because that's how I intend to get wealthy.

 

[Luvinlakelife]

Are you absolutely sure it was smoke and not steam? It is not unusual for any outboard to produce some steam that does not dissipate quickly in still, highly saturated air. If it was smoke, it should have had a distinct smell, like burned oil, or burned gasoline, or a burned electrical appliance.

Thank you for the reply, I greatly appreciate the help. After reading your reply I too am confident it was steam because of the lack of odor, we have a fishing boat and a jet ski that are both 2 strokes and after they have sat in dry dock for a while in the down season (the jet ski especially) they will puff a little smoke at idle but it has a darker color than the incident with the pontoon and that very distinct 2 stroke oil smell. it was just the fact of how it lingered in the air that had me concerned and I completely over looked the possibility of the air saturation from the down pour on both sides holding the steam under the bridge but we have had it out a couple of times since and everything is running fine. Thanks again, this will definitely be my go to source for any issues that arise in the future.

 

[Luvinlakelife]

Thank you for the reply, I am very grateful for your time and expertise. We have an inboard and some 2 stroke engines but this is my first Honda as well as first 4 stroke outboard. I thought... or I hoped is more accurate that it was steam it was just the way the cloud (very misty white) lingered in the air that gave me concern. Another member pointed out the air being heavily saturated on both sides of the bridge would have held the steam in place and taken longer to dissipate and after reading your reply, it was definitely raining hard enough water could have gotten close to or on the exhaust. Thanks again, with me being in the office 6 days a week I am certainly thankful to have found a forum of knowledgeable and courteous boat owners to consult with any issues that come up.