I agree with most of what Kevin has said except for the need to take carbs
off to clean the float chambers. I've had a fuel contamination problem
(maybe since I've owned my TR6) and have taken my float chambers off
literally dozens of times to dump the gas and the little black specs
(varnish particles). I've been known to take some of that canned air and
blow it around the inside of the top of the float chamber but most of the
stuff is going to be floating in the gas when you take the bottom of the
fuel chamber off. Taking the carbs off is way more trouble and you can take
the float chambers off about 10 or 12 times in the same time as it takes to
get carbs off completely....especially considering you'll have to re-balance
the carbs.
You don't have to take the fuel valve out either as you can clean out the
fuel valve by taking a clean piece of fuel line and hooking it up at the
inlet on the carb and blowing air through the valve while tapping the valve
up and down with your finger. It also provides a little test of the valve
cause once your clear it of crud and if it's closing as it should you won't
be able to blow air through your clean piece of fuel line.
And a new gasket isn't mandatory either unless you've torn the old one or
it's really past its useful life. The fuel level in the chamber should be
below the gasket when the float is properly adjusted so its function is not
to keep gas from leaking out of a "full" fuel chamber. It's more there to
provide a seal between the two pieces of the float chamber and keep gas from
"splashing" out as it slops around in the float chamber. Don't put any kind
of gasket sealer on them either or you'll be cleaning that out of you float
chambers too...ask me how I know this...right Tom?
I've done the multiple filter thing on the fuel lines and between them and
the BG44K fuel treatment ($20 at NAPA) I'm beginning to win the battle of
the black specs.
But I could be wrong about this too.
Bud Rolofson
----- Original Message -----
From: "Martin A. Secrest" <msecrest@erols.com>
To: <triumphs@autox.team.net>
Sent: Wednesday, November 29, 2000 4:08 PM
Subject: [Fwd: TR6 Suddenly Runs Rich]
>
> X-Mozilla-Status2: 00000000
> Message-ID: <3A258C52.2F173A5F@erols.com>
> Date: Wed, 29 Nov 2000 18:08:03 -0500
> From: "Martin A. Secrest" <msecrest@erols.com>
> Reply-To: msecrest@erols.com
> X-Mailer: Mozilla 4.7 [en] (Win98; U)
> X-Accept-Language: en
> MIME-Version: 1.0
> To: "Riggs, R Kevin" <rkriggs@ugsolutions.com>
> Subject: Re: TR6 Suddenly Runs Rich
> References: <CD08E3B5CC13D31189F90800365DDA03D61C86@hsvntx.ug.eds.com>
>
> Kevin:
>
> Thanks for a very thorough write-up. I'm posting this reply to the list
so
> others can enjoy this veritably on-topic discussion.
>
> I've taken apart float bowls before, never particularly to my enjoyment.
And
> you're right -- Grose Jets are unreliable mechanisms. I tried a pair on
my GT6,
> and after lots of misery with them, went back to the original needle
valves.
>
> --
> Martin Secrest
> TR6, GT6
>
> "Riggs, R Kevin" wrote:
>
> > Martin,
> >
> > I think the problem is most likely the fuel shut-off valve that screws
into
> > the carb body within the float-bowl chamber. I believe most rebuild
kits
> > these days come with a "gross valve", though I've heard many people
express
> > their preference for the old, original style valves that came in the
> > carburetors.
> >
> > When the fuel pump sends fuel to the carb, it gets dumped into the float
> > bowl. A plastic float pivots on a stainless steel arm in this pool of
gas,
> > and the pivot arm raises and lowers a stem extending from the float
valve.
> > When the fuel level is high enough, the valve closes entirely, shutting
off
> > the flow of fuel to the carb. When enough has been siphoned through the
> > carburettor, the float drops down, opening the valve again.
> >
> > The typical problem is that crud is pumped into the float bowl and finds
its
> > way into the float valve, preventing it from closing. From then on, you
> > have a steady stream of gas into the float bowl, where it eventually
bubbles
> > up into the carb, spoiling your mixture.
> >
> > The short term fix for the problem is a few whacks on the float bowl
with a
> > block of wood. If you're lucky, this will dislodge the crud in the
float
> > valve. For a while...
> >
> > The longer term fix involves several steps. The most critical step is
to
> > stop the crud flowing into the carbs. The minimum fix is to put a good
> > quality filter as close to the carbs as you can get it, and replacing
this
> > filter often. You might also consider replacing rubber and possibly
steel
> > fuel lines (use your judgement on what might be in poor condition), and
> > conceivably cleaning and/or sealing your fuel tank.
> >
> > Some people have told me that they've cleaned the float bowls with the
carbs
> > on the car. I can't get my fingers in there to do that, so I've always
> > pulled the carbs off the car to get underneath them and remove the float
> > bowls. Odds are you can continue to use the existing valve, though
you'll
> > certainly want to unscrew it from the carb body and clean it thoroughly.
> > None of this should have any effect on the rest of your carb
adjustments.
> > However, you'll probably want to replace the float-bowl gasket at a
minimum,
> > and you might want to replace the crushable brass washer that seals the
> > float valve to the carb body. Consider replacing the valve itself,
though I
> > don't consider this a wear item.
> >
> > If you recently replaced your mechanical fuel pump with an electric fuel
> > pump, that could also cause essentially the same problem simply by
supplying
> > more fuel pressure to the carb than the float valve can handle. This is
the
> > problem I suffered for years before finally identifying it and adding a
> > pressure regulator between the pump and carbs. I'm also trying to deal
with
> > dirt in the fuel line, though, because my car sat unused for several
years.
> > In addition to varnish in the lines and carbs themselves, I think I may
have
> > corrosion from the tank.
> >
> > Hope this helps,
> > Kevin Riggs
> > '72 TR6
> >
> > > -----Original Message-----
> > > From: Martin A. Secrest [SMTP:msecrest@erols.com]
> > > Sent: Wednesday, November 29, 2000 3:52 PM
> > > To: triumphs@autox.team.net
> > > Subject: TR6 Suddenly Runs Rich
> > >
> > >
> > > All:
> > >
> > > The thing about owning two Triumphs is that it's like having a pair of
> > > Pugs -- pay attention to one, and the other gets jealous. My GT6
throws
> > > a u-joint, and now ...
> > >
> > > My '72 TR6 suddenly runs so rich, the plugs foul in short order
> > > (showing the black sooty plug evidence after a few hours running
time).
> > > Lots of white smoke, too. Any ideas as to what would cause this? I
set
> > > the mixture a couple months ago to spot-on, the K&N air filters
weren't
> > > dirty (but I'm cleaning them anyway), and the carburetors were
> > > professionally rebuilt a couple years ago by the PO.
> > >
> > > The choke setting seems normal too, at first glance. Hmm.
> > >
> > > I haven't gotten into the mixture settings yet, but those don't just
up
> > > and change themselves (unlike women).
> > >
> > > --
> > > Martin Secrest
> > > 72 TR6
> > > 73 GT6
> > >
> > > PS: Just a little auto/gender humor ...
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