Air Filter for an Outboard?

Redonthehead

Recruit
Joined
Jan 20, 2004
Messages
4
Howdy! Anyone with experience making an air filter for a small outboard? Yeah, yeah, the water isn't dusty. But I haul my 25 hp Merc down a LOT of dirt roads and you should see the poor thing. There's enough dirt in the carb throat to grow a potato! (does that date me?) Anyway, I figured I could cobble something up - maybe oiled foam from a mower?
 

Forktail

Ensign
Joined
Feb 11, 2002
Messages
977
Re: Air Filter for an Outboard?

Sounds to me like you need an outboard cover for trailering. They make some excellent one's here:<br /><br />www.toughduckmarine.com<br /><br />Otherwise some oil impregnated paanty-hose held on with rubber bands will work. Just remember to remove them before starting it.
 
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DJ

Guest
Re: Air Filter for an Outboard?

Redonthehead,<br /><br />I'm not sure an external cover would keep the dust out. Dust can get into some amazing places.<br /><br />Anyway, I think you are on the right track by stuffing something in the carb. throat. Your idea sounds reasonable.
 

Forktail

Ensign
Joined
Feb 11, 2002
Messages
977
Re: Air Filter for an Outboard?

Nothing but dirt road here. I use those covers and they are custom fit for each particular outboard. Any one. They Velcro and zip for a snug fit, and they virtually eliminate any dust getting in the outboard. They are breathable and have fuzzy stuff on the inside for no scratches. Plus you'll be protected from rock chips, mud, sun, rain, etc.
 

andrewkafp

Lieutenant Commander
Joined
Mar 15, 2003
Messages
1,668
Re: Air Filter for an Outboard?

Both solutions look good.. But D.J's is more cost effective.. Those covers cost heaps down here.<br />Just make sure you remove before usage.. :eek:
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Air Filter for an Outboard?

I've got a piece of foam I shove in the prop hub as well.......my thinking is dirt circulation up thru exhaust, but you still have 2 holes in mid section for dirt to enter too....
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Air Filter for an Outboard?

Unless the foam or cover is EXTREMELY pourous, you will in effect be choking the motor. These outboards are jetted for certain conditions and air-flows. Adding a sheet, foam, mesh, whatever will in effect change that airflow, and adversely affect performance. Just cover it up when you're transporting it and leave it be for actual use...<br />- Scott
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Air Filter for an Outboard?

Cover the carb opening with duct tape until you get to where you're going. Simple, but effective! Carry a roll with you for the ride back.
 
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DJ

Guest
Re: Air Filter for an Outboard?

I guess I should have added that the foam should be removed before operating the engine. For transport only.
 

Forktail

Ensign
Joined
Feb 11, 2002
Messages
977
Re: Air Filter for an Outboard?

I have to remove the air silencers on my smaller outboards to get at the carbs. Pain in the butt.<br /><br />A custom fit cover that protects the entire outboard (lower unit too) will cost you about $110. You won't have to stuff anything in the hub. Plus it does a lot more than keep the dust out.
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Air Filter for an Outboard?

Forktail, I had a complete engine cover for my last 115 Johnny, and your right, it does more than keep dirt out....when you're going down the highway, it's chaffing the paint off of your engine......Great storage tool, but not for the road....
 

pine island fred

Lieutenant Junior Grade
Joined
Dec 20, 2002
Messages
1,144
Re: Air Filter for an Outboard?

agree with chinewalker. 2 strokes run rich enough now to promote a cooler burn. adding any kind of restriction will only increase the richness of the mixture. like having a stuck choke.
 

Forktail

Ensign
Joined
Feb 11, 2002
Messages
977
Re: Air Filter for an Outboard?

walleyehed, there are two versions of these covers available. One is for storage, and one is for travel. It appears you're using the storage cover for travel. Or a different brand. <br /><br />The one for storage is made out of a thicker, stiffer material and has no soft/fuzzy inner liner. I think the material is called Sunbrella. These covers are more expensive.<br /><br />The one for travel is made out of thinner, more flexible material that includes a soft/fuzzy no-scratch lining. I think the material is called Softliner. These covers are actually less expensive than the storage one's. A cover for the 25 Merc will run about $110....cheaper than a carb rebuild or engine overhaul.<br /><br />Both cover options are perfect custom fits, no matter the make, model, or year. Each one is made individually and specifically for your outboard. They will even custom fit the cover if you have a hydrofoil or Dolefin on the cav plate. They do not flap or move while traveling. In fact, they go on very tightly and use zippers and Velcro to snug them up.<br /><br />I've used these covers for years, traveling in the worst conditions Canada and Alaska have to offer. Never once have I had the covers chafe the paint off my outboards.<br /><br />I just hate to see a guy stuffing things in his carb to keep the dust out (what about the rest of the motor?), when he can get a complete cover. Cheap protection.
 
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DJ

Guest
Re: Air Filter for an Outboard?

Take a run down to the airport. <br /><br />Look at the jet engine powered planes on the tarmac that are being stored. Guess what they do? Yep, they stuff a special fitting "plug" in the intake. Of course, they usually remember to remove it before taking off! :eek: <br /><br />People that operate airplanes are pretty good at remembering small details like that. ;)
 
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