Bonneville America Forums Forums Technical Forums General Tech Leaking America (mystery overflow pipes?)

Hi all,
I hate to be the guy that only posts when his bike is broke...but

A few of you may remember i had some drama with my 07 America some time ago where, in exchange for favours (a website) a Triumph mechanic agreed to do some work on my bike off the books and left me with carbs (sans needles) gently pissing petrol everywhere and a bike that couldnt ride.

Anyway, i bit the bullet, got a local garage to look at it and through a series of adventures ended up replacing the carbs with new (second hand) ones and having a bunch of other work done to it (that he'd broke).

All happy, bike running fine.

So i go away for 7 months, store it in a garage, stabiliser, calipers off, battery disconnected and (once i buy a new battery) when i get back it starts up totally fine with no problems.

EXCEPT

a mystery rubber hose is gently leaking fuel from the bottom of the bike (in front of the rear wheel, next to the tank overflow pipe).

Now it's not the carb overflow, as that terminates just above my chain.
It's not my tank overflow because (after that was unsealed after Triumph guy borked it) that terminates _next) to this mystery pipe.

I've swapped fuel for new fuel, Cleaned carbs with carb cleaner and in truth i'm not sure where to go from there...

Currently it's a bugger to start (takes ages to catch, on full choke with gentle throttle) but when it does start it runs totally fine (apart from one incident where it died on me...but i think i'd run out of fuel...doh).

Any clues guys? it's gently pissing fuel at a steady drip and i'm not really comfortable riding it for a significant distance whilst it's incontinent.

Thanks for your time and patience

Ant

Airbox drain?

Ah, what's that then? and why would it be dripping petrol?

The hose in question is right next to the tank one...probably slightly bigger in width if memory serves..

Ant

Not sure. Just spitballin'. When I pulled the airbox out of my first bike back in 2002, I could swear there was a drain tube for the airbox, and it was fatter. You said it had been leaking gas due to missing needles? Could that have leaked into the airbox too?

Sounds to me like you may still have a float not working right. Maybe not adjusted right or maybe allowing some fuel past when closed due to wear, damage, dirt, or a combination of the 3.

I'll leap on that and give it a go today

Would that explain the rough/poor starting also?

do you turn the petrol valve off when you park the bike?? if not try that, and see if problem stops, if it does, you have probably got sticky needle. sounds like the bike is flooded when you are trying to start it??

hmm, odder and odder.
Took it over to my local mechanic and ironically it apparently didn't leak whilst it was with him.

Regardless he drained the carbs and tinkered with it and it still didn't leak.

chuffed to bits i ride home, spot another Bonnie America/Speedmaster (blue and black, south birmingham anyone?) and park.

after a few snaps of the bike and a swift pint i wander back outside, she's stood there like an old cat casually leaking again.

I'm guessing doing the float thang involves taking the carbs off, but just in case it _isn't_ that...are there any alternative possibilities? or is it most likely the float.

Interestingly, even with the fuel tap off it still leaks away...not sure how that's possible (unless there's simply a large built up of petrol in the airbox).

nice day for a ride mind

Ant

Mis-adjusted or damaged float can effect starting making it hard to start due to flooding. That would be why it starts sometimes and others not. Once you manage to dry the plugs from cranking it with the throttle open enough to spark it fires. Sounds like a float may be hanging up if it doesn't always do it. That starting could be ignition as an alternative (loose connection, etc..) but that still wouldn't make the carbs leak and the carbs leaking make me believe it has to do with that. Look at the needles and seats for damage or dirt, check the floats for fuel in them, and check for anywhere things are rubbing or not moving smoothly. You can check your float level by attaching a piece of clear tube to the bowl drain, hold that up along side the carb, open the drain, and the level in the tube will be what the level inside the bowl is. It should be slightly shy of the bowl/body joint.

Is it possible that the leaking takes place after you fill the tank and park the bike? If so, don't fill the tank so much. It's happened to me.

You might have a cracked vent tube in the tank but I've never heard of this happening.

So...

Having a free day I decided to take the carbs off and check out the floats

[caveat, this is the second time I've done this but i'm still a tech newb - Computers, no problem, Engines I have no clue]

drained them (about the same level-ish), took off electric connecters, loosened airbox and slid them out to the left ala Dinqua's guide (which is awesome and thanks btw).

tipped upside down and took the covers off, no dirt or grime and floats look...well...floaty i guess.

Interestingly the right carb (as it sits on the bike) still had fuel in it (despite the fact i'd drained it properly).

regardless i spray a bit of carb cleaner in there, make sure there's no excess and put everything back together.

now when i turn the fuel tap to 'on' a veritable stream of fuel comes out (not just little drips).

So things i've noticed :

my tanks petcock doesn't seem to do a very good job when it's in the 'off' position

when i drain the carbs, i can drain the left to empty but the right hand carb i can drain to empty, wait a few minutes and drain it again...and again..and again...

I havn't checked out the needle (too much for one day) but i'm thinking the following :

1) right float probably buggered (maybe?)
2) fuel if flowing right through the carbs, out through the airbox and out through the airbox overflow.
3) taking the carbs off is a ball ache.

so i'm thinking of :

ripping the airbox out (hah, lets see you drain now!)
replacing floats and needles on carbs (which i'd need to do sans airbox anyway right?)
stick some K&N's on
replace the petcock with a non leaky one.

net result :

if it still doesn't work, at least i can get to my carbs easier

thoughts on any of the above?

I think the Dog nailed it when he suggested wear or dirt in the Float needle cavity or the float needle itself. Id drop the bowl, pull the float off and inspect the needle seat and needle end. There might be some garbage stuck up there.

The airbox drain should have a plug in the end. If not, it can suck road grime into airbox, carbs, and so on.

Just checking - is the float needle located on the top of the carbs (shiny side) or the bottom - as it sits on the bike?

(apologies for the ignorance, i'm only just finding my way around the carbs)

When i took the carbs out i basically just unscrewed the bottom (where the floats are) and...well if i'm honest poked them a bit then sprayed them with carb cleaner - i couldn't quite see a technique to pull them off. Are you saying once i get them off i can access the float needle cavity/needle from there?

(the needle acts like a sort of trap door to fuel right? so if stuff is stuck up there it's basically an 'open door'?)

i'll check out the airbox drain also.

cheers again all

I saw your other post and that brass seat that is missing is the problem.That is the part that the float needle seats against to stem the flow of fuel.

Ah, apologies for confusing matters with the other post - was basically something on my mind at the same time but _that_ set of carbs are my original ones that the Triumph guy damaged.

The set that's on my bike currently are replacement ones and (in theory) 100% fine apart from, we assume, the needle/float problem that's causing it to dribble and wee like an old cat.

I don't suppose there's any short cut in cleaning the float needle that _doesn't_ involve me removing the carbs again?

no worries if not, but i figured i'd check before i tried to pull them off again

Ant

You can do it with the carbs still mounted. Just put a light colored towel over the engine case to catch anything that escapes and get a small mirror so you can see what you're doing.

I'll give it a go that way then, i feel nervous every time I have to wrench them past the rubber holding sleeves

There goes my excuse to justify stripping the airbox to my missus though!

If you haven't already,get stainless allen head screws to replace the bowl screws. They make life much easier when working on the carbs in place.

To really get the carb parts clean you're gonna have to pull them and soak them in carb cleaner. Then spray them and wipe them off. And once you think-hey good job-do it again.

The floats are on the "non shiny" side or the bottom. Needles and springs on the top. The floats are held on by a hinge with a little pin on it that you can slide off and lose...or I mean clean. Amd then if you need to adjust your float level do like Ian said with the rubber tube. But check that first before you rip it apart-obviously so you know how much to change the level if need be.
Did I confuse you? Tell you what fly me over and for a pint or two I'll fix it for you. Haha!
Good luck

Just an update.
Cleaned the Needles (in the top bit with the spring)
Cleaned the Float Needles also (which i'd gotten confused with something else briefly).

Tbh there wasn't really any crud anywhere but i gave the think a liberal soak in carb cleaner etc.

Put it back together (getting good at that now)and now it leaks slightly less than before i.e. it's gone back to how it was at the beginning of the problem (rapid droplets of fuel).

Interestingly also it smelt strongly of raw (as a pose to deep fried or baked) petrol when it was running (this is a new thing).

Going to book it into the garage tomorrow, either i've missed something simple the 4-5 times i've taken the carbs off or...well...missed something simple

If it's not one thing it's another eh?

Ant

Thanks for the update, look forward to the resolution of this problem. Good luck, let us know what happens.

I had a Hardley that leaked fuel when parked on the hot crankcase, you could hear it go: 'sizzzle' as it dripped onto the hot parts. Fixed with a pair of vice grips (locking pliers) on the fuel line.... stuck, leaking floats on the carb, they only have one don't ya know...good luck

Sadly the mechanic is out for the week so it'll be next monday - sods law dictates it'll be another wasted summer before she's running again.

Sorely tempted to take the airbox out though, probably cause more problems than it's worth than this stage through.

Hm, having time on my hands i'm inclined to give another crack at the bike (he can't take it till wednesday now).

I've pulled the carbs off (still attached) a few times.
Removed float bowls, float needle (looks fine to me) and normal needle. All has been liberally sprayed with carb cleaner.

Thus far, no joy in terms of stopping the leaking and the bike still takes a bit of 'coaxing' to start.

Do we think i should remove the carbs entirely? (and if so how worried do i have to be about the throttle link)

if not the carbs, is there anything else it could be?

Thanks for your time and patience on this one, just keen to get riding!

Ant

Ant, is it possible that one of the floats is cracked or has a leak in it?
This would prevent it from rising and shutting off the flow of gas.

I don't think so, I had a fairly close look at them and they seemed fairly fine (I'm reasonably sure they're not that old).

Getting pretty bummed out by the whole thing, I think the bike's spent more time being repaired now than it has had being ridden.

If the throttle linkage is easy to take on and off i'm tempted to try popping my missus Scrambler carbs on just to see if it leaks then - wondering if it _is_ the carbs or maybe i'm missing something...

?

Ant