Total Motorcycle Community Forums

Yam 78 Xs400

While cleaning out my air filters, I noticed that the construction is pretty flimsy...(I think these are the old-style airfilters), they're just two aluminium plates with metal mesh epoxied / soldered on!!! Is this for real???
Now I know that air-filiters are not exactly an engineering design challenge, but this is ridiculous.

I wonder if the previous owner tried some homebrew or moonshine-brand filters... trouble is they look exactly like the photo on the haynes manuals. What gives??

Plus a trivia question: How does oil get inito air filters? gunk from the air, regurgitation from the carbs??

Is there some kind of filter media? Like foam or paper? What you described sounds like it may be an inner cage to support a foam element......?

The oil in the airbox and on the filter is most likely from the engine crankcase vent(s) that are routed into the airbox (low-pressure) to help evacuate the crankcase. And to give the vapors someplace to go that's eco-friendly......

Aha... now I know wht function the balance pipe serves for the intakes (one of my previous posts)... cool!!! thanks a lot.
Yup there is a foam element that I did not mention. Well, $30 for this flimsy thing is hardly justified...but then again, I guess I shouldnt have chosen to be a poverty-stricken grad student.

Yep sounds about like a stock filter set-up.... right down to 30 bills for a hunk of open pore foam.....

Why not just spend a few extra and get a pair of K&N Cone filters and jet up a notch? The kn's will protect better anyway, and you might even get a decent performance boost to boot ...

TechBMW: Too late, I already bought new stock filters... just wanted to know if I was being ripped off.

No-standard filters would eed that I adjust the jets and all, I just want to get my bike running so I have wheels till I can afford to fix my car. Then I can play around with the bike, I've been meaning to look inside the engine and get new valves and stuff, maybe over the summer

Ahhh well, good luck with the car then! Once you get back to the bike, you know where to find us