Funny place to have fuel tank vents

So the hoses are f*cked and the left vent is blocked with corroded alloy dust.
Can I unscrew it without anything falling off inside?

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Yes, but be careful. The captive nuts they screw into are prone to coming loose and the nipple may snap off if forced. Best way to clean them out seems to be a small drill bit spun with fingers and liberal applications of compressed air and vinegar.

The allegedly unscrew, but I couldn't unscrew my left side one when it got blocked. It loosened, but just seemed to turn without coming out, so I nipped it back up. I used a small drill bit to loosen the crud, twisting it carefully with my fingers. I also poked a piece of wire form the top, and squirted some vinegar (thanks Pete) in from both ends with a syringe. Got it cleared.

Lots of threads about tank drains on here

if you are lucky it will unscrew - one of mine won't - same as Mark

but as Pete and Mark say putting vinegar or another mild acid (coca cola, lemonade etc) down from the top and clearing the botttom woth a 0.8mm drill has worked for many people here.

Then you need to route the hoses so that they drain freely

Hi Folks,

These vents really tick me off.

I've been sticking white vinegar down the hole which does the trick...I forgot to do it recently so now have to get the tank up again to shove a drill bit in it as it's blocked.

You have to block the 3 holes around the filler for my next trick, which is:
Previously, I have successfully used a drinking straw & blown down it to unblock; it couldn't have been a major block that time!
I have also used a bicycle pump.
I'm loath to use my compressor air gun on it in anger yet...bit worried that it might be too much!


Cheers!

Mine seems to have been fine (now that is a hostage to fortune!!)
since i got the pipe run right so that the water drain empties and does not pool.

I did this by linking the two hoses with a series of light-weight orange cable ties and running them in parallel all the way.
Then when i put the tank on it was easier to see the hose run and ensure that it drops all the way from the spigot and that it is not trapped.

Hi Jon,
Thanks for the tip although I have to admit that I'm not 100% sure on exactly what you mean (me being stupid!). Are the holes in the same place on a 1200?

On my 1100 they stick out facing the rear of the bike & the hoses immediately have to do a 90 degree turn otherwise they're fouled by the frame. I like the idea of cable ties & a less obstructed run.

I find the small holes in the actual metal fitting get blocked with a sludge that is whiteish. It's no problem unblocking them with a small drill bit it's just a pain having to do it.

if ever you get the chance to take a snap of your solution I'd like to see it but don't feel like you have to!!!

Cheers...

It is really hard to see it without lifting the b-loody tank.
My vents are in the same place as Buell blokes (first post in this thread) and stick out the back - one on each side.

I decided that the corrosion was probably due to a puddle of salty water (road salt + rain) sitting around the join between the metal threaded boss and the metal spigot. So I wanted to keep that area dry.

I found that by linking the hoses about 3"/75mm after they leave the spigot they sat together closer to the back of the tank then dropped as one.  By linking them again every 100mm/4" i could easily feel which hoses they were and keep them free while i lowered the tank.

From memory the 1100 the nipples point down and on the 1200's they poke out the back. (Shrug?)

Nope. Just checked. 1100's out the back as well. Sorry.

Cheers, Guys!
Pete, I'd love it if they pointed downwards; it would save a lot of faffing.

I'll lift the tank (yet again!) tonight when I get home & do the drill bit thing on the nipples although on my bike it's only the left one that gets blocked!

Jon, I'll try your idea & see if it makes any difference....now it's turning autumnal it'd be nice to have a vent that actually drains......might even be able to get some petrol tonight re: HGV crisis, panic, end of the world scenario over here right now......

Cheers, all...

I never unblocked my water vent drain pipe, vinegar pools right at the top near the entry point, as well as the bottom being full of corroded alloy.
A drill bit did f*ck all except move out some of the corroded dust. From the top there was no real point of entry as it was blocked straight off.
This is a job for a winter tear down, whilst you can still ride enjoy your bike and dont f*ck with the stupid vent job.
Wasting hours of precious in this day and age time on that job is rediculous.

My feeling is its only water ingresss that goes in there its not the fuel vent which is at the top.
Am uncertain what the other bottom vent does? The right side one. As that one doesnt seem to get blocked?
As for water I rarely ride in the rain what little might enter there can be no worse than the E10 other poor f*ckers are fueling their bikes with.
I also dont wash my bikes as they dont get shit high as dont ride in the rain.
A little water only causes the odd hiccup in detonation, no worse than other oily shit thats being fed in there.

As for the hoses use some silicon tubing as it curves around nicely and is resistant to kinking/folding.
Join the the left side to the right side with a T piece, use a longer length for the left side and then connecting the T down piece to the drain pipe making sure its open to the atmosphere.
You can give it a gentle tug with the down pipe to see how freely its moving.

BB,
I like the non-kink silicon tube idea; that's a good one.
My tubes are just how you describe...one shorter than the other & joined by a t-piece.
Like you, I have no idea what the right hand side vent does, either!

Hammered down this morning on my ride in so I'll have a nice pool of water in my tank cap area merrily rusting those 3 screws away!

Cheers

Red Leader wrote:

BB,
I like the non-kink silicon tube idea; that's a good one.
My tubes are just how you describe...one shorter than the other & joined by a t-piece.
Like you, I have no idea what the right hand side vent does, either!

Hammered down this morning on my ride in so I'll have a nice pool of water in my tank cap area merrily rusting those 3 screws away!

Cheers

The plastic tubes harden and can become brittle, the ends can form and then become loose.
Silicon tubes never harden though they can split over a very very long time.
Often used for brake bleed kits.
Easy cure for rusty bolts replace them with stainless items like someone seems to have done with mine.

Right hand pipe is the air breather into the tank (allows the fuel to come out) personally i would not join the two in case the breather in gets blocked by sludge etc.

lcjohnny wrote:

Right hand pipe is the air breather into the tank (allows the fuel to come out) personally i would not join the two in case the breather in gets blocked by sludge etc.

My pipes are protected by the belly pan, but I hear what your saying
Use two long silicon hoses then loosley connect them as they pass the battery, next time am in there this winter will seperate them

Cheers Jon,
I was assuming that the hoses I have were meant to be joined....have done upwards of 35k miles on it now so I'm assuming it's as it's meant to be.
I'll have a look at the diagrams in the parts book tonight just to see how MG did it.
Whatever happens I'll be lifting the bloody tank again!
Cheers...

@Red Leader. 35k miles and no problems?
I have only done 6k on my GRiSO.

Probable that i am being mechanically paranoid again

Conjoined or not conjoined that is the question, whether the weather f*cks two seperate hoses or just the one of them. If they are going to sludge up then its probable it could be either or both.
Then again the shitty left one could in theory project its internal catastrophies onto the other and bypass the exit line altogether.

Hi Folks,

Well, BB & Jon I hope we're talking about the same thing as on my parts catalogue (page 25) it's parts 15 & 16 & they are indeed joined; so, conjoined it is!
Hey, Jon... maybe I've been lucky re: issues.
Off the top of my head I've only had a few annoyances:

  Speedo change at 6k in those innocent days when I just thought my speedo was a duff one & they weren't all crap!

  Front wheel bearings went at 20kish....big potholes, I guess!

  Bevel box gasket (the metal one) started to leak last year but I changed it this summer....that wasn't cheap & maybe I could have re-used the
  original gasket on reflection....

  A few pad changes front & rear.

  A bit of oil paranoia when ENI changed to 80 rather than 85 in the gearbox (might be the other way round)....

Think that's it... GRiSO is my first 'modern' bike, really... just mainly rode Brit singles & twins before that so you can imagine my amazement when I got the GRiSO....it was a bit of an epiphany!

Just had my MOT last Tuesday.... I was advised I'll need to change my front discs as there's a bit of sideways play with them & the steering bearing is on it's way out (I haven't noticed anything amiss)..... I'll tackle them next year!

Maybe someone will chime in to let me know if there's anything I need to worry about after 35k ....

Lifted the tank again this weekend & yes, the left hole was blocked....reamed out with trusty drill bit once again......I can feel a bit better about leaving it in the rain again!

Cheers to you all....

What Brit bikes did you own?
I had a 1951 Excelsior Roadmaster 2 (197 villiers 6e), a 1958 Royal Enfield Clipper 350 and a 1971 B50ss - not the cream of the crop lol

Hi Jon,

I've had a few, blimey:

In no particular order:

I've had an AJS M16 then got an M20, my brother's Velocette Viper, a little BSA Bantam, A Lambretta GP200 (not British!!!)which was ace & incredibly light & reliable in spite of the jeers!, a BSA 44 which was never that reliable (me having no money to fully sort at the time!).

I am a RE fan!
Like you, I had a RE 350 ... a great bike. The 350 is a sweet engine!!!
I've still got a Bullet 500 which was made in India 2002.
I had an RE with a 250 Villiers engine in it.

I will be buying the new RE 350 Classic when it arrives in the UK next year - it's just been released in India & it's got an updated engine & the frame is a new design... I'm a bit of a sucker for RE bikes! It'll sit happily at 60ish with minimal vibes compared to the old 500.... if RE make a new 500 based on the new 350 I should imagine I'll get one of them as well but I doubt the 500 will see the light of day for a year or two

...and I still have my 1966 Triumph T100ss which is seemingly bulletproof (it's got a Pazon on it!)!

Think that's it!

Cheers

Nice selection - the T100 was always my favourite Trumpet

My B50 was noisy and vibratory but strong and reliable...
until i dropped a valve chasing one of the first LC250s i saw (I was 2 up lol)

Yeah, that little Triumph is a pretty bike...it should have been Sherwood Green over Alaskan White for the year but mine's Pacific Blue over Alaskan white...Lord knows why?!

Just got new stainless wheels & spokes built for it this summer so have put some miles on it the last few months.

I do love a single, though!!!!

Cheers
R