Motorbike Forums


Reply
Thread Tools Display Modes

Gas spewing from carb drain tubes

 
 
Matt Johnson
Guest
Posts: n/a
 
      03-17-2010, 02:57 PM
On Mar 17, 2:10*am, totallydeadmail...@yahoo.co.uk (The Older
Gentleman) wrote:
> Matt Johnson <mouche.librem...@gmail.com> wrote:
> > checked it out and gas is leaking from all four drain tubes. i turned
> > the drain screws all the way around the opposite direction, but that
> > didnt change anything. ill take the carb off and try to post some pics
> > tonight.

>
> I think the simplest solution is probably the most accurate. You haven't
> tightened up the drain screws properly.
>
> Krusty's right when he says O-rings deteriorate with age, but for all
> four to go at the same time? Nah.
>
> --
> BMW K1100LT *Ducati 750SS *Honda CB400F *Triumph Street Triple
> Suzuki TS250ER GN250 *Damn, back to six bikes!
> Try Googling before asking a damn silly question.
> chateau dot murray at idnet dot com


ok yes to clarify there are four carbs. i suppose i should have called
'it' the carburetor assembly? im new to this... anyways i definitely
didnt take them apart, only removed because my choke cable got loose
and was sort of dangling and the bike wouldnt start. being so new to
this, im a little wary about popping open my float bowls and fiddling
around. All my o rings should be new because (allthough its an 81) the
engine was recently rebuilt. The 'carburetor assembly' is very clean
and looks brand new. The guy i bought it from said essentially the
whole bike was new accept for the frame, the tank, and the instrument
cluster. might have been bs but nothing on it LOOKS thirty years old.
ok so is the new consensus that the drain screws all came out some
during the carb assembly removal and just need to be tightened? that
seems about as likely as something getting inside all of them and
blocking the needles... ill get out a digital camera and get some pics
on here.

p.s. i feel silly for thinking the drain screws were like an on/off
switch. i've been looking at carburetor assembly diagrams for days now
and they are clearly screws... sigh, chalk it up to inexperience! haha
 
Reply With Quote
 
 
 
 
Matt Johnson
Guest
Posts: n/a
 
      03-17-2010, 03:17 PM
On Mar 17, 10:57*am, Matt Johnson <mouche.librem...@gmail.com> wrote:
> On Mar 17, 2:10*am, totallydeadmail...@yahoo.co.uk (The Older
>
>
>
>
>
> Gentleman) wrote:
> > Matt Johnson <mouche.librem...@gmail.com> wrote:
> > > checked it out and gas is leaking from all four drain tubes. i turned
> > > the drain screws all the way around the opposite direction, but that
> > > didnt change anything. ill take the carb off and try to post some pics
> > > tonight.

>
> > I think the simplest solution is probably the most accurate. You haven't
> > tightened up the drain screws properly.

>
> > Krusty's right when he says O-rings deteriorate with age, but for all
> > four to go at the same time? Nah.

>
> > --
> > BMW K1100LT *Ducati 750SS *Honda CB400F *Triumph Street Triple
> > Suzuki TS250ER GN250 *Damn, back to six bikes!
> > Try Googling before asking a damn silly question.
> > chateau dot murray at idnet dot com

>
> ok yes to clarify there are four carbs. i suppose i should have called
> 'it' the carburetor assembly? im new to this... anyways i definitely
> didnt take them apart, only removed because my choke cable got loose
> and was sort of dangling and the bike wouldnt start. being so new to
> this, im a little wary about popping open my float bowls and fiddling
> around. All my o rings should be new because (allthough its an 81) the
> engine was recently rebuilt. The 'carburetor assembly' is very clean
> and looks brand new. The guy i bought it from said essentially the
> whole bike was new accept for the frame, the tank, and the instrument
> cluster. might have been bs but nothing on it LOOKS thirty years old.
> ok so is the new consensus that the drain screws all came out some
> during the carb assembly removal and just need to be tightened? that
> seems about as likely as something getting inside all of them and
> blocking the needles... ill get out a digital camera and get some pics
> on here.
>
> p.s. i feel silly for thinking the drain screws were like an on/off
> switch. i've been looking at carburetor assembly diagrams for days now
> and they are clearly screws... sigh, chalk it up to inexperience! haha


http://i4.photobucket.com/albums/y11...o/DSCN1555.jpg
http://i4.photobucket.com/albums/y11...o/DSCN1557.jpg
http://i4.photobucket.com/albums/y11...o/DSCN1556.jpg

<a href="http://s4.photobucket.com/albums/y113/luckeyzero/?
action=view&current=DSCN1555.jpg" target="_blank"><img src="http://
i4.photobucket.com/albums/y113/luckeyzero/DSCN1555.jpg" border="0"
alt="Photobucket"></a>
<a href="http://s4.photobucket.com/albums/y113/luckeyzero/?
action=view&current=DSCN1556.jpg" target="_blank"><img src="http://
i4.photobucket.com/albums/y113/luckeyzero/DSCN1556.jpg" border="0"
alt="Photobucket"></a>
<a href="http://s4.photobucket.com/albums/y113/luckeyzero/?
action=view&current=DSCN1557.jpg" target="_blank"><img src="http://
i4.photobucket.com/albums/y113/luckeyzero/DSCN1557.jpg" border="0"
alt="Photobucket"></a>
 
Reply With Quote
 
TOG@Toil
Guest
Posts: n/a
 
      03-17-2010, 03:27 PM
On 17 Mar, 15:57, Matt Johnson <mouche.librem...@gmail.com> wrote:
> On Mar 17, 2:10*am, totallydeadmail...@yahoo.co.uk (The Older
>
>
>
> Gentleman) wrote:
> > Matt Johnson <mouche.librem...@gmail.com> wrote:
> > > checked it out and gas is leaking from all four drain tubes. i turned
> > > the drain screws all the way around the opposite direction, but that
> > > didnt change anything. ill take the carb off and try to post some pics
> > > tonight.

>
> > I think the simplest solution is probably the most accurate. You haven't
> > tightened up the drain screws properly.

>
> > Krusty's right when he says O-rings deteriorate with age, but for all
> > four to go at the same time? Nah.

>
> > --
> > BMW K1100LT *Ducati 750SS *Honda CB400F *Triumph Street Triple
> > Suzuki TS250ER GN250 *Damn, back to six bikes!
> > Try Googling before asking a damn silly question.
> > chateau dot murray at idnet dot com

>
> ok yes to clarify there are four carbs. i suppose i should have called
> 'it' the carburetor assembly? im new to this... anyways i definitely
> didnt take them apart, only removed because my choke cable got loose
> and was sort of dangling and the bike wouldnt start. being so new to
> this, im a little wary about popping open my float bowls and fiddling
> around. All my o rings should be new because (allthough its an 81) the
> engine was recently rebuilt. The 'carburetor assembly' is very clean
> and looks brand new. The guy i bought it from said essentially the
> whole bike was new accept for the frame, the tank, and the instrument
> cluster. might have been bs but nothing on it LOOKS thirty years old.
> ok so is the new consensus that the drain screws all came out some
> during the carb assembly removal and just need to be tightened? that
> seems about as likely as something getting inside all of them and
> blocking the needles... ill get out a digital camera and get some pics
> on here.
>
> p.s. i feel silly for thinking the drain screws were like an on/off
> switch. i've been looking at carburetor assembly diagrams for days now
> and they are clearly screws... sigh, chalk it up to inexperience! haha


Can't get the photos to load for some reason, but the most likely
explanation is still that someone - not you, then - didn't tighten up
the screws before refitting the carbs. Just tighten them up. Caution -
nip them up carefully, because it's quite easy to strip the threads in
the float bowls.

Oh, and whichever forgetful sod forgot to tighten them up probably
forgot to tighten the choke cable assembly too. I wonder what else he
forgot?
 
Reply With Quote
 
paul c
Guest
Posts: n/a
 
      03-17-2010, 03:51 PM
Matt Johnson wrote:
>...
>> p.s. i feel silly for thinking the drain screws were like an on/off
>> switch. i've been looking at carburetor assembly diagrams for days now
>> and they are clearly screws... sigh, chalk it up to inexperience! haha

>
> http://i4.photobucket.com/albums/y11...o/DSCN1555.jpg
> http://i4.photobucket.com/albums/y11...o/DSCN1557.jpg
> http://i4.photobucket.com/albums/y11...o/DSCN1556.jpg
> ...


Nice snaps, from the appearance of the screws (no gouging that I can
see), it looks like somebody was careful.

On the #2 carb, I see a hose is missing from what looks to be an
accelerator pump.
 
Reply With Quote
 
TOG@Toil
Guest
Posts: n/a
 
      03-17-2010, 04:02 PM
On 17 Mar, 16:51, paul c <toledobythe...@oohay.ac> wrote:
> Matt Johnson wrote:
> >...
> >> p.s. i feel silly for thinking the drain screws were like an on/off
> >> switch. i've been looking at carburetor assembly diagrams for days now
> >> and they are clearly screws... sigh, chalk it up to inexperience! haha

>
> >http://i4.photobucket.com/albums/y11...o/DSCN1555.jpg
> >http://i4.photobucket.com/albums/y11...o/DSCN1557.jpg
> >http://i4.photobucket.com/albums/y11...o/DSCN1556.jpg
> > ...

>
> Nice snaps, from the appearance of the screws (no gouging that I can
> see), it looks like somebody was careful.
>
> On the #2 carb, I see a hose is missing from what looks to be an
> accelerator pump.


Did the 900C have accelerator pump carbs? Paging Mr Olson.
 
Reply With Quote
 
paul c
Guest
Posts: n/a
 
      03-17-2010, 04:10 PM
TOG@Toil wrote:
> On 17 Mar, 16:51, paul c <toledobythe...@oohay.ac> wrote:

....
>> On the #2 carb, I see a hose is missing from what looks to be an
>> accelerator pump.

>
> Did the 900C have accelerator pump carbs? Paging Mr Olson.


Sorry, I may have used the wrong name, meant the gizmo (is is
deceleration pump) that reduces backfiring when the throttle is closed
at speed.
 
Reply With Quote
 
`
Guest
Posts: n/a
 
      03-17-2010, 06:28 PM
On Mar 17, 10:10*am, paul c <toledobythe...@oohay.ac> wrote:

> Sorry, I may have used the wrong name, meant the gizmo (is is
> deceleration pump) that reduces backfiring when the throttle is closed
> at speed.


6: DIAPHRAGM SET, PUMP 217860-001 $69.41

 
Reply With Quote
 
paul c
Guest
Posts: n/a
 
      03-17-2010, 08:56 PM
Mark Olson wrote:
> paul c wrote:
>> TOG@Toil wrote:
>>> On 17 Mar, 16:51, paul c <toledobythe...@oohay.ac> wrote:

>> ...
>>>> On the #2 carb, I see a hose is missing from what looks to be an
>>>> accelerator pump.
>>>
>>> Did the 900C have accelerator pump carbs? Paging Mr Olson.

>>
>> Sorry, I may have used the wrong name, meant the gizmo (is is
>> deceleration pump) that reduces backfiring when the throttle is closed
>> at speed.

>
> It had both of those gizmos- an accelerator pump on one carb and air cutoff
> valves ...


thanks, that's the name I was looking for.
 
Reply With Quote
 
paul c
Guest
Posts: n/a
 
      03-18-2010, 11:35 PM
paul c wrote:
> Mark Olson wrote:
>> paul c wrote:
>>> TOG@Toil wrote:
>>>> On 17 Mar, 16:51, paul c <toledobythe...@oohay.ac> wrote:
>>> ...
>>>>> On the #2 carb, I see a hose is missing from what looks to be an
>>>>> accelerator pump.
>>>>
>>>> Did the 900C have accelerator pump carbs? Paging Mr Olson.
>>>
>>> Sorry, I may have used the wrong name, meant the gizmo (is is
>>> deceleration pump) that reduces backfiring when the throttle is
>>> closed at speed.

>>
>> It had both of those gizmos- an accelerator pump on one carb and air
>> cutoff
>> valves ...

>
> thanks, that's the name I was looking for.


Friend's CB750 is long gone, air cutoff on all four makes sense, just
trying to remember why the accelerator pump (which I think was what was
pictured) was only on one carb. Mark?
 
Reply With Quote
 
`
Guest
Posts: n/a
 
      03-19-2010, 11:46 AM
On Mar 18, 5:35*pm, paul c <toledobythe...@oohay.ac> wrote:

> Friend's CB750 is long gone, air cutoff on all four makes sense, just
> trying to remember why the accelerator pump (which I think was what was
> pictured) was only on one carb.


One pump is plenty to meet the requirement for extra fuel during low
vacuum conditions.

If you study the carburetor drawings, you'll see that there are rubber
tubes connecting all four carbs together. The accelerator pump output
goes to those tubes so all four carbs get a squirt of fuel when the
throttle is opened but engine vacuum is too low to suck fuel through
the idle ports and the needle jet.
 
Reply With Quote
 
 
 
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT. The time now is 01:46 AM.

1 2 3 4 5 6 7 8 9