what is this thing??

While digging into this little project, i popped off the air box, to do a visal of the carbs, they look new which is good, i plan on upgrading the jets on it anyways, back to what i was saying, screwed on the air box is a steel filterish, deep fry basket looking contraption, it was full of junk do i took out off the clean it, no i can't get the damn think back in. I assume this is to catch, large debris before it gets to the filter, do i need this? Well it mess anything up running without it? Keep in mind i will be running proper air filter. The bike is an 85 vf760f.

 

It's a screen to keep large stuff out of the carbs. I didn't even know that it came off. 99% of the time you'd probably be OK to run without it and just use the air filter. If it was full of crud already then I would guess that either your filter is somehow letting stuff through or you're getting a bunch of stuff coming out of the breather tube. I sold my 84 VF750F earlier so can't confirm but I am pretty sure the breather tube enters the airbox between the filter and screen you're talking about. The crud would seem to indicate that screen was catching something so you might want to consider putting it back in or finding out what is clogging it up.

 

It is commonly called a backfire screen. They do get crudded up after time. It will clean up nicely using oven cleaner.

 

There was only a little crud on it. The reason i see for that is, whoever has it before oiled thehell out of the air filter and it ran off on to the screen