Newbie Intro - Newbie Question -Tip Over Valve

[Joe_V11]

After reading this thread and looking at the pics and diagram, I'm thinking the illustrated fitment might be backward. You seem to be using the "tipover valve" as a way to get air into the fuel tank, and it may work for that in helping to avoid tank suck. But the purpose of the carbon canister, I'm pretty sure, is to collect hydrocarbons that come out of the tank as it sits (if there is a build-up of pressure in the headspace of the tank due to temperature fluctuation) - when the bike is restarted, the hydrocarbons are pulled off the carbon and into the throttle bodies where they become part of the fuel/air mixture introduced to the engine. For this to work, the valve must let air out, but not in. The orientation suggested in this thread lets air in, not out, if I've read the posts right.

 

I'm interested in this because I recently replaced the stock air box with pods (for the "looks cool" factor) and at the same time removed the carbon canisters and associated plumbing. Since then there's been some occurrences of the bike losing power for short periods during sustained high-way-speed riding, leaving me to wonder whether I have taken care of the plumbing issues properly. (Restarting hasn't been a problem and low-speed riding gives me no problems.) What I've done is to plug the vacuum ports in the throttle bodies and just run the two hoses coming off the bottom of the tank (the one with the tipover valve and another one that's just a hose, I think it went into the airbox) down toward the bottom of the engine, letting them vent to atmosphere. The tipover valve I've left alone, and I believe it's plumbed the opposite to the photo - that is, long end is up, but plumbed into the tank.

 

I'd appreciate getting anyone's thoughts on this, in the meantime I'll continue researching and check with some non-Guzzi folks for outside advice.

[Garsdad]

The valve is, to the best of my knowledge, supposed to let air go both ways when it is upright, and block the flow of fuel when it is not. Thus, vented fumes can travel to the canister, and air can be pulled into the tank to replace the fuel and keep the tank from collapsing under the vacuum.

 

Mine didn't work. The PO warned me of the problem when I picked it up. Once I got home, I took it out and just placed a straight plastic fitting in it's place. I removed the carbon canister at the same time. This hose is not under any pressure, so I didn't see the need for hose clamps. I worried about fumes in my garage from the tank venting without the canister, but I have yet to experience anything that I can smell. Heck, my pressure washer stinks up the place if I don't let it cool completely before putting it away, but the Tenni is always fine.

 

Yes, I know if I crash I run the risk of my bike bursting into flames from the rush of fuel that will come gushing out the vent line. In the event of a crash, I hope I am able to worry about such things. I found that futzing around with it to make it work was a pain in the ass, pulling over every hour to burp the tank was a pain in the ass ( I rode the 800 miles home from where I bought it doing this) so I removed the source of the pain in my ass.

 

Garsdad