Vacuum bungs

[mozzup]

Hi all

Just noticed both the rubber bungs on the vacuum points on throttle have split, not 100% sure they've been leaking, but what sort of symptoms would appear if they had? - Just weak mixture? I've always thought the intake noisy but I don't suppose drawing in air through small pipes would make an 'no airbox' sound?

Will motorworks have these I wonder?

Cheers
Moz

 

[Wrigsby1]

Motorworks have 'em. Get a couple of spares as they are cheap. They perish on all the injected BM's. If you pull one off when the bike is running you will get an idea of the symptoms. If you don't notice much difference they are well and truly f'ecked!

 

[motobiker]

they cost 75p each.. I replace mine every year or so. order them with the 12,000 mile service kit.

Motorworks part no - FUA60594

(Bike lives outside in all weather.. and as has been said.. they do perish)

 

[MattW]

I noticed one was missing soon after I bought my 1100 and the other was perished (after a 100 mile ride home from buying it). I ordered a few from Motorworks and taped up the vac points until they arrived. Cant say I noticed a huge difference when I sealed them up (although the bike and all the usual BMW 'character' was new to me at the time).

 

[FatAl]

Hi all

Just noticed both the rubber bungs on the vacuum points on throttle have split, not 100% sure they've been leaking, but what sort of symptoms would appear if they had? - Just weak mixture? I've always thought the intake noisy but I don't suppose drawing in air through small pipes would make an 'no airbox' sound?

Will motorworks have these I wonder?

Cheers
Moz

I've got two spare since I sold my GS1150, you can have them free, send me your address, I'll post them out to you.


(I tried to PM you, but my facilility seems to be on the blink))

 

[mozzup]

I've got two spare since I sold my GS1150, you can have them free, send me your address, I'll post them out to you.


(I tried to PM you, but my facilility seems to be on the blink))

Fatal, that's a really generous offer, I ordered a few last night & will tape up in meantime. Perhaps someone else will find theirs are U/S on seeing this thread and avail themselves of yours. Many thanks though

 

[Hong Kong Nick]

Motorworks have 'em. Get a couple of spares as they are cheap. They perish on all the injected BM's. If you pull one off when the bike is running you will get an idea of the symptoms. If you don't notice much difference they are well and truly f'ecked!

Sorry for the simple question but a series of issues recently has made my bike run really badly ... a couple of things have made it better and there are a few more things that need checking. However, I noticed my little bungs were totally fecked, too, so I would like to know what the real 'symptoms' are for this issue ... appreciate the advice

Cheers,

Nick

 

[MattW]

With mine, when I replaced the missing bung I thought I could detect that the idle smoothed out a bit. However there wasn't much in it (if anything) - no noticeable difference at speed though. The biggest help was balancing the TB's.

All this said, a missing bung(s) will lean out the mixture (although I'm not sure if the engine management wouldn't automatically compensate through CO / Lambda readings?...) and an over lean mixture is best avoided.

 

[Ogmios]

as i'm a Luddite i could be totally wrong, but if it were an Airhead i suspected of leaks....

i'd spray WD40 around the suspect area - if the revs rise - there's a leak / if they dont, there isn't.
that any help?
oh - and Good Luck.

 

[Wrigsby1]

Sorry for the simple question but a series of issues recently has made my bike run really badly ... a couple of things have made it better and there are a few more things that need checking. However, I noticed my little bungs were totally fecked, too, so I would like to know what the real 'symptoms' are for this issue ... appreciate the advice

Cheers,

Nick

Lumpy running at idle/hard to balance, and more "sucky" noises, ahem! I just fixed my K11 which had a 1" split in one of the injector manifolds (and cracked bungs...and cracked c/case breather!) and ran like crap at tickover, only to take off as normal when accellerating. Some stupid git had adjusted the anti tamper screws to compensate.

As stated before, start simple and work up. Older R11's may have cracked rubber manifolds by now which may affect 'em.

 

[fatnfast]

I balanced my throttle bodies last week and forgot to put them back on. The only difference was an increase in idle speed, ie, when I replaced them the revs dropped a little. Obviously, they have an effect on the mixture at idle.

 

[Steptoe]

. However, I noticed my little bungs were totally fecked, too, so I would like to know what the real 'symptoms' are for this issue ... appreciate the advice

Cheers,

Nick

An increase in idle speed .

You can still balance the idle without them fitted, and turn the idle down by turning the idle screws in.
You'll only notice a difference ( apart from the increase in idle speed) when one is missing and it runs a bit lumpy at idle. If both are missing you may not even notice it.

Riding without them fitted means you'l be sucking in shite through the bung tubes.

 

[Hong Kong Nick]

Oaky .. thanks all ... that might explain one or two problems.

Might have to take the thing in and get it serviced properly, anyway - it's well overdue

Cheers again

Nick

 

[(RIP) Yamaha1]

A mate of mine bought a '96 1100 recently, and his has a balance pipe between the two stubs, instead of the bungs.

Anybody know anything about the reasoning behind this?

Mike

 

[Wrigsby1]

A mate of mine bought a '96 1100 recently, and his has a balance pipe between the two stubs, instead of the bungs.

Anybody know anything about the reasoning behind this?

Mike

Summat a yank probably did and posted it on a forum A K11 forum had a Yank inspired maze of tubing and one way valves that took the place of the bugs. Didn't copy 'em