Bonneville America Forums Forums Technical Forums General Tech Fuel tank breather hose

Picked up the speedmaster today complete with new exhausts and dyno tune.It sounds great, got that parrallel twin note and loud enough. The guys removed the AI but left the snorkel and were able to get 6 more hp and not run lean. However on the way home it cut out. Electrics fine, fuel fine , but was'nt recieving the fuel. Opened the fuel cap , put it back on and it started. Turns out there is a valve in the breather line and if its not completely vertical it shuts off and then no air flow. Any comments anyone?

nonononononononoonono yes....

Mines been changed...twice. Is it a new one (06 or 07)?? If it's a bit older rip the valve out. Mine ran without it in for two weeks. If it's under warrenty then tell them to take it out run it for a couple of weeks to make sure that is the problem, and it gives them a chance to get the part in - UNDER WARRENTY. My dealer says that Triumph know there's a bit of a problem with them.

It could be however that the breather pipe is trapped. check that first.

I didn't know there was a valve. I have heard several times now about it being pinched when the tank is put back on. Where is the breather valve located? I know in the breather tube but where in the tube?

I have had 2 replaced under warrantee. In the end I ripped it off the bike and have had no more problems. The valve is low down near where the pipes hang down underneath. But up in a little holder. I just got so P****d off with it that it had to go.

If you trace the fuel vent hose from under the tank, back over the carbs to a black plastic thingy clamped on the frame behind the right carb. That thingy is the "tip-over" valve. One of the first things I did when I got my new bike was to remove the valve, then spray dry graphite lube into both ends, and shake it up and down so lube gets to all internal parts (you'll hear the valve inside clicking away when you shake it). Then I re-installed the valve, and it has worked flawlessly. One way to check the valve and vent line is to remove your gas cap, place a length of hose on the metal vent air-entry tube, and try and suck some air, as you would through a drinking straw. If you get lots of air, then your vent line is fine...if it's hard to draw air through, then check to make sure the valve is installed vertically onto it's housing clamp, or re-lube with the graphite. Use a dry lube...Don't use a liquid lube as that will gunk up the valve with time. The bike can be on it's sidestand when you check the air flow.

Got ya. I had no idea what that was.Thanx

Thanks from me too.... Had no idea where it physically was...just knew it's bleeding annoying!

Singring....What good advice

Man i love this site. So much useful information on the real world problems that happen.
Thanks too

i have had my tank off a couple of times, i have even followed that line and my just comes out at the bottom if the bike. no valve my bike is 2002 maybe on the earlier bikes it was not added.

All I have is a hose on mine also. Valve must have been added later....

Ditto. Or maybe the black '02s just know better

I have an 04 and mine is right where stated above. Wendys America also has the valve and is also an 04.

Couldn't you just remove the valve the the vent hose is always open to the air?

I don't see why not.

back from the service cente and they just took the valve out. Said they'll t a new one back in at the 1000 km service if i want. Dont see he point though

I don't either. But I was getting them to put the new tank on FOC so they did it all the same...