Function of Airbox?

[Jewel1964]

What is the function of the airbox? I left it off my 1972 65 hp after I changed the fuel lines. I recently noticed that the foam insulation inside the cover is soaked with 2 stroke oil. Is this expected? Why? Thanks.

 

[rodbolt]

Re: Function of Airbox?

yep<br /> not only does the airbox make things quieter it also collects the normal amount of fuel spitback and routes it to the crankcase,man it must be nice to be smart enough to re-engineer a decent product. my hats off to ya

 

[angus63]

Re: Function of Airbox?

Air box is designed to keep water and foreign matter out of the carbs. Also creates some intake air resistance so running without will cause a lean condition. Some boxes also have connections to bearings to drain and reburn scavenged oil. Also helps prevent fires caused by backfire. Running without one is not a good idea. I would check all of the lines again for leaks to find what is soaking your cover, but run with the airbox installed.<br />Good luck

 

[angus63]

Re: Function of Airbox?

If you ran it for several hours without the airbox, then I would agree with Rodbolt's reply for the cause of the insulation mess (especially at low speed).

 

[outboardpart]

Re: Function of Airbox?

Not all outboards have an airbox (air silencer) instaled from the factory. I have several 25 and 35 hp motors mid 1980 models that did not come with one.If you check the parts book it does not show an air box for those models. All these motors run fine without the airbox.

 

[rodbolt]

Re: Function of Airbox?

thats why I dont redesign them. if you will look there are also a lot of 25-35 models WITH an airbox, I just fix em and not re-engineer them. some models will run so lean without the airbox that piston failure is assured. other it does not seem to bother.<br /> but some carbs are calibrated with the airbox resistance in the calculation. without it it just does not work. there is a long story behind this that whacked me for 2 days. wont go there now

 

[G DANE]

Re: Function of Airbox?

The airbox also silences airflow to carbs. And unless you already have bad hearing, who wants to listen to more noise than neccesary ?? Although it seems like some people do ??