Large diameter hose near carbs/airbox (ammended after search

[emt803]

I don't have my pc and have no access to my manual currently (long story). I need to resolve this tomorrow before I ride again and since I don't know what these tubes and pieces are called its kind of difficult to search. I need a patient veteran forum members help. Since I've heard the airbox can pop out on its own, I wanted to check it out due to dropping the bike. I wanted to make sure no gas or oil went into it, plus I just wanted to see the thing. The following couple of issues were simply observations while taking the tank cover off. I didn't know if any of them were pertinent so I will give as much info as I observed.
1. My front two tank cover screws have vibrated out. I removed the 2 gas cap screws marked with the triangle indentation and noticed that two of the silver screws were missing and one was missing the nut and falls out if you let it. I've covered the gas cap with saran wrap for now, although there is a runout port with hose for gas overflow. Can water get into my tank without these two screws missing?
2. I looked at my KnM air filter and can still see ambient light through the filter. When I put it back in, I saw written on the filter to add "oil" but didn't. I assume its to form a better seal but didn't do it before asking you guys and its an easy part to access if need be. I lined the bottom ring up with filter using a screw driver run around the inner bottom part of the filter as a guide since it wouldn't stick. The thin seal at the top was very stringy and was too big around to fit as snuggly as the bottom and I kind of had to stuff it in there. I also noticed a metal strip running the length of the air filter and pointed it forward. Did I do that wrong?
3. Luckily, from looking underneath the airbox I could see that all four were connected still. What is confusing me is that there are two "j" shaped tubes coming from under the two outermost holes. The one on the left had a clip on the end and I found another tube that was hanging free and connected the two. I don't see a similiar tube on the right hand side. Just the same "j" shaped tube pointing open and down. These two tubes are beside the word "mikuna" and are beside two silver little screws. In the middle of where the airbox connects I found a long tube that has a screw on the end along with a strip of silver metal, but isn't attached to anything either. What should I do with these miscellaneous tubes that sit under where the airbox seats? Have I hurt the bike running it disconnected?

[emt803]

Sorry guys, can't post pics right now...

[emt803]

Okay, spent 4 hours searching and have come to the conclusion that those two candy cane shaped tubes are vents for the carbs. I d/c'ed the large diameter tube that looks as if it should connect somewhere due to it having a collar on its end. It was just sitting beside the left carb vent and seems to be connected to something at the bottom of the bike about midline. I'm dropping the fairings soon and checking it out. I see no large diameter port near the airbox or at the carbs. (by large diameter, I mean big enough that the vent tubes fit it perfectly.
I'm more concerned now with why the thin upper foam seal on the air filter is so stringy and larger in diameter than the filter. Gas maybe? It didn't smell of gas and everything was dry thank goodness.

[emt803]

I'm going to answer my own post here after hours of searching to help anyone else that might have the same question. I am 99% sure that the hose that I am referring to is the crankcase breather tube. I am not even attempting to take off the airbox to reattach this thing and have read that it shouldn't matter in the grand scheme of things. I am concerned with the tube being simply open and unattached (due to the fact that I have to store her outside) and am pretty sure that water somehow dropping down said tube would not be good in the crank case. Does anyone want to make a suggestion on this? I've read about people attaching KnN filters to these, but I'm not so what size would be needed or if that would be over kill etc etc.
The large foam ring on top of the KnN airfilter fits perfectly on the inside top cover of the airbox above the filter. Problem solved. Hope this helps another rookie out there.

[taggy]

look on ebay for crankcase breather filters. all you need to know is the diameter of the pipe. got one on the race bike might be useful if you don't want stuff going down it!

[emt803]

look on ebay for crankcase breather filters. all you need to know is the diameter of the pipe. got one on the race bike might be useful if you don't want stuff going down it!

Thanx Taggy... I've read that some racers like there breather hose routed to the airbox b/c you can add a minimal amount of HP. I guess in racing every little bit helps, but for street riding I'm assuming the difference would be minimal. I didn't really like the idea of "oily air" from the crankcase going through the filter (although I do have a KnN filter and it uses oil, PROBABLY not the same, but maybe it could assist with the dirt trapping, no clue) and I definetly didn't like the chances of oil coming back in the airbox if I overfilled it by accident. Someone let me know if I am way off. I just don't want to take off the airbox to get the hose back on it. Kind of a tight fit as is.

[reelrazor]

The crankcase vent hose connects to the airbox 'downstream' of your air filter.

Biggest problem with leaving it unhooked means that you now have a 15mm hole allowing unfiltered air into the airbox/carbs/engine(remember it is DOWSTREAM of the filter.

It aint gonne be a huge deal to ride it a short distance (home) like that..may change the state of tune enough to cause minor issues. I'd remedy it as soon as possible though.

[emt803]

Thanx RR... I appreciate your time. I figured if Yamaha didn't want it on the airbox, it wouldn't be there. Opinions seemed to vary and what to do with the bugger. I'm not messing with the airbox right now though and I see no other way of getting to the port. I was just wondering though, would sticking the filter on it only limited trash going in, and still give "tuning issues" as stated?

[taggy]

forgot to add, ive not got a proper filter in the race bike so it makes bugger all difference to me! technically you can just plug the hole in the box if you put a filter on it.

[emt803]

When I eventually work up the nerve to remove the box or the tank I will probably attach it. Not trying to beat a dead horse here, but I am learning how/ why things work. What is the advantage mechanically of running a breather tube through the airbox into the carbs? Or is it like an overflow and the possible liquids that might end up in the airbox are more suitable going back into the system via the crankcase rather than elsewhere? ie: on the ground, into the carbs etc...