Hey Everybody!

From Pasadena, CA. Just bought a 2005 GS500 with 3500 miles used. 1st bike  Had been sitting around with past owner. Had some rust issues I've taken care of in the gas tank. Also cleaned the carbs and checked the valve clearance. Thing runs like a BEAUT now

I love this forum. Found tons of answers for my repairs here before needing to post, but now I'll get to the topic.

During the reassembly I noticed the small port on the bottom side of the AIR BOX was missing a hose. After investigation I noticed it was hose number 8 in this diagram: http://www.bikebandit.com/oem-parts/2005-suzuki-gs500f/o/m16075#sch591348

So a few things:

1. Is it necessary to have this hose at all or could I just plug the hole with a rubber cap?
2. If it's necessary, is spending a bunch of money on all the OEM parts recommended or can I just build something similar? It's hard to tell what the design for the cap/end is like from the diagram, so any insights on that would be great if I end up building my own version...
3. Anyone know what size hose would that be if I were to buy my own hose? Another post said it was 1/4" but it'd be nice to have that verified.

That's pretty much it for this topic for now! Thanks in advance!

That hose is simply for overflow in case of a tip over/carb problem, the fuel wont sit in the air box causing a potential fire hazard. I wouldnt plug it, just get some vacuum line or fuel line and zip tie it on there. I cant say for sure the size, but its bigger than 1/4, probably 3/8 would be my guess. Just measure the fitting on your airbox to be sure. The cap shown in the picture actually has a slit in it for drainage, Im not sure why its not left plain like most overflow hoses. It shouldnt be necessary to reproduce that, unless someone else has more knowledge on the subject.

That slit at the end of the tube might be so air is not taken in from the opening there and only fuel can drip out.
Total guess though.

Don't think a slit would seal well for vacuum.... I took it to be for stopping dust and crud mixing with any fuel drips and making a mud plug in tube end?..  yeah I know the oil one is open but oil is heavier/weeps thru more?.. plus a blocked tube for fuel would be bad if the airbox started to pool up?!