Dusty air

[Jake Windemere]

I drove my boat with my Honda outboard upriver in a brutal wind. The glacial silt from the river sandbars was airborne and even completely obscured my vision at one point.

I am wondering if anyone has any insight regarding the ingestion of dusty air in the carburetors of outboards and whether it causes problems.

Is airborne silt too fine to cause a problem when it goes through the carbs, cylinders, and exhaust? Or have mechanics noted cylinder or other damage due to dust/silt ingestion?

 

[psteurer]

Re: Dusty air

I doubt very seriously if you would have a problem. The problem would occur if you were running the outboard when all the silt was flying. If you have ever put your hand over a carburetor throat when it was running, you would experience a tremendous vacuum created.

If you want to be extremely safe (which I am), I would rinse the outside of the outboard with a hose. Then remove the cover and vacuum out any dust that might have gotten in.

 

[robert graham]

Re: Dusty air

That silt/dust being sucked into your motor would be rough on valve guides, cylinders, etc. if you ran it through that area very often. If it were my motor I would make an oiled foam rubber air filter either for the outside of the motor shroud or in the carb airbox area. Rig it so you could install it and remove it quicky and easily because the air flow restriction probably would reduce your motor performance. The back and sides of motor shrouds have air intakes and it would be fairly easy to rig up a foam filter in that area, maybe held in place with a bungee cord or similar. I've heard of aircraft flying through volcanic ash dust plumes high in the sky have totally fried all engines very quickly. Good Luck!

 

[psteurer]

Re: Dusty air

My mistake. I just re-read the original post and see you did run the motor through all that dust (my first read, I thought you trailered it through it). Good suggestion on the oiled foam filter. You may be able to buy one already made from a lawnmower parts store and jury rig it to your application.

 

[Tig]

Re: Dusty air

I don't think you will have any detectable ill effects from a one time occurrence.
As mentioned clean the engine. Also remove the air intake and wash that out thoroughly. There will be some dust settled in there also.
Any air filter that you install will reduce air flow to some degree and as a result will richen up the carb mixture. If you do go this route take a good look or picture of you plugs now and watch for them to darken. Sign of fouling. They should be tan. You may have to adjust the carb(s)
Maybe keep a bonnet (pillow case with draw string) on board to throw over the motor next time. It's not as efficient as a filter but more convenient for occasional use.

 

[Mas]

Re: Dusty air

Dust on the water is rarely an issue. If it is, seems to me it wouldn't be any fun.

I would not mess with the engineering and don't boat on dusty days.

MAS

 

[Jake Windemere]

Re: Dusty air

I would have preferred to have not driven through the glacial silt dust storm but as your can tell from the photo, I needed to get back to the boat ramp, which by the way is in line with the mountain peak behind the dust storm.

It was either drive through the dust storm or abandon ship. The river was freezing and I was running out of daylight.

I like the idea of an oiled foam filter. I suspect that if it is made correctly that it would not be much of a restriction on the carbs.

I also like the pillow case idea. That would have been great.

I recall the incident with the volcanic ash. It "totaled" a jetliner. It did so much damage to the engines and the fuselage that it was too expensive to repair. The pilots lost visibility out of the windshields when the ash sandblasted the windows. Imagine having to land a jet by looking out the side windows!

The engines shut down automatically and after a scary period of time dropping toward Cook Inlet the pilots were able to override the shutdown and restart the engines to land safely in Anchorage.

 

[Jake Windemere]

Re: Dusty air

Yesterday I took the cowling off and did an inspection. Not too much in the way of dust or grit.

I gave the power head a good soapy wash and wiped out the inside of the cowling.

I ran the engine in a 90 gallon garbage can and it purred like a kitten.

I am amazed at how sweet my Hondas run (I have three - 50, 20, and 2).

I suspect that the circuitous route taken by the air is sufficient to allow the larger particles of dust to drop out.

I am not too worried about the dust after doing that inspection. However, as I get ready to winterize my engine I will do a compression test to add to my maintenance records.

 

[robert graham]

Re: Dusty air

I'm confident your motor suffered no great damage from the dust storm but if you had to operate in those conditions a lot then I'm sure it would eat your motor internals up. You could make a loop of 1"thick by 8" wide foam rubber like a big rubber band that would just slip down over the motor shroud quicky if you ever need it. Keep it rolled up in your tool box/kit when not in use. The foam wouldn't even need to be oiled to stop 95% of the grit. Hey, maybe we need to get a patent!...Call it the "Grit-Gitter" or something catchy like that!