1996 Johnson 25 hp

Well, newbie here, so I've got a question:

I just purchased a 1996 Johnson 25 hp J25TELEDA, 2 cylinder. The carb has no kind
of air cleaner, air silencer, or any other kind of filter. I've found some pics on Google
that also don't show one.

I can't seem to find one on any of the on-line parts diagrams either.

Is it possible that OMC has deemed a filter to be un-necessary?

Just sold a '96 that was the same way ... wide open under the cowling. No problems ...

Most outboards that I owned just had open carbs? Have you seen them with air filters?

Captain Ahab said:

Most outboards that I owned just had open carbs? Have you seen them with air filters?

Click to expand...

Some have an 'air box' that seems to have no filtration in it.
Don't know why they would bother. Maybe it might act as a backfire containment
or deflection ???

The air box is mostly used as a silencer to cut down on the noise. No need for a filter as there is no dust on the water. Try running a V-6 200 hp at 6000 rpm with no air box........... its ear splitting loud

The new Suzuki outboards are the only motors using an air filter...as far as I know.

Charger nailed it.
The use of air boxes and "filters" are mainly used to knock down the intake noise. Even the shapes of the air boxes on later engines were designed to re-route and reduce that noise.

Well, that makes sense. I just found another reference to 'air silencer' box on another thread.

Thanks guys!

Pappy said:

Charger nailed it.
The use of air boxes and "filters" are mainly used to knock down the intake noise. Even the shapes of the air boxes on later engines were designed to re-route and reduce that noise.

Click to expand...

I agree with all the above posts.. No dust on the water!! I've owned numerous 9.9's.. 20's .. 30's etc .. Even my new 2006 30hp merc and 2013 15hp merc ( both 2 strokes) have open carbs.

The only motor I've ever owned without open carbs was my old 1981 70hp Johnson .. It had an air box , but no filters. And a 1967 evinrude 40hp had a screen, probably to keep bugs out!

I have a '97 J25 and I thought for the longest time that it was missing a filter, eventually figured out they don't have them.

Back in the late 70s these motors(521cc) had air boxes. They disappeared in the early 80s and haven't been seen since. Mid 80s and newer, no air boxes. Cheaper to manufacture that way. These engines never had filters.

What I don't understand is ,the smaller ones, 6, 8 ,9.9, 15 have air boxes as well as larger motors say 75 hp and up . At least the ones I've seen.

I just sold my 1995 Yamaha 40 commercial that had an airbox.

Yeah the gray matter is kicking in , I remember seeing a 35 merc that had one. I also read some where that that on smaller motors that the teeth on the fly wheel acted as a fan to help force air in the carb.

That being said I wonder how complicated it would be to build an airbox/filter for a motor without one strictly to cut down on the noise...although there might not be dust on the water there sure is dust on the road that can coat everything - especially with 2 strokes and the oily residue left after the more volatile gasoline dries out of the carb.

Just for shits & giggles I'm going to see if I can make something up for my motor, if nothing else to deflect the noise backwards.