Subject: Re: [TR] TR3. Fuel mixture too rich.

From: "[email-masked]" <[email-masked]>
Date: Mon, 1 Aug 2016 07:55:05 -0500

Have you chcked the float level and the needle & seat valve?

I would pull the pistons and dampers again and double check for any obstructions, they should act equally.  Check the inside walls of the dome for excessive wear, they can get warped.  

Good luck,
Bill B
TS30800L

Sent from my UNIVAC

On Jul 31, 2016, at 3:33 PM, David Griffiths <[email-masked]> wrote:

Hello all. I would welcome some advice on one of the carbs on my TR3, #15005. It’s primarily the rear one that is giving me trouble. 

The car has been running too rich for a long while and I decided to sort it out on the weekend. I took the air filters off. The first thing of interest was a difference in the behaviour of the two pistons. Both carbs have damper oil in them. The piston of the front carb was pretty hard to push up - I pushed a good way, and when I let go it fell quickly down to the bottom with a satisfying metallic thud. The rear piston didn’t offer the same resistance to being manually displaced upward. It was easier to push up, and when I let go of it, it fell more slowly down and not with a metal to metal click - more a soft noise. However, when I removed the damper, it fell quickly and with the same “clack” as the forward carb. So it’s centering properly I think. I removed the chamber, spring and piston and cleaned them carefully, and put them back in, but still exactly the same behaviour. Both carbs have the same damper oil. So that is one thing that puzzles me. 

The front carb is running a bit rich - it shows yellow on the Gunson colortune, but the plugs are ok and the rpm does not increase to speak of when I lift the piston a little. 
The rear carb, judged by the thick, black layer of soot on the plugs, is a lot worse. When I lift the piston the revs increase noticeably and stay there. The trouble is, that even with the mixture adjusting nut screwed totally upwards it’s still far too rich. The car may be sucking a bit of air along the throttle shaft, but this should if anything lean out the mix. 

There is one more thing that might be important, but I haven’t researched it up yet. Just under each carb there is some kind of metal contact with the exhaust manifold, a kind of metal buttress or similar. It was hard to get a good look at it today. Well this is wet on the rear one and dry on the front one. I can’t say more just yet until I get a better look at this area. There is some smoke wifting up from that area after the metal heats up, but it doesn’t smell like burning fuel or oil. 

The car runs very well and I think that the rest of the motor is more or less properly adjusted. Valves are good, breaker gap is correct, plugs are new and gap correct. Timing is ok. Coil I have not checked, but the car runs and idles fine. 

So there it is. One problem - mixture too rich even with nut screwed up to the max. One maybe problem - piston of same (rear) carb falls slowly. 

Very grateful for any suggestions, 
Dave

** [email-masked] **

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]

** [email-masked] **

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: David Porter <[email-masked]>
Date: Mon, 1 Aug 2016 07:06:36 -0600

3 thoughts.. there are different dampers for different applications. Are 
they both the same?

next is the needles. Are they the same? 3rd is the jet ovalized?

DaveP

On 7/31/2016 2:33 PM, David Griffiths wrote:
> Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]

-- 
Dave Porter Porter Custom Bicycles 2909 Arno St. NE Albuquerque, NM 
87107 505-352-1378 Go HERE: my world www.porterbikes.com/

---

From: "Randall" <[email-masked]>
Date: Mon, 1 Aug 2016 09:13:02 -0400

>  The rear piston didn't offer
> the same resistance to being manually displaced upward. It was easier to
> push up, and when I let go of it, it fell more slowly down and not with a
> metal to metal click - more a soft noise. However, when I removed the
> damper, it fell quickly and with the same "clack" as the forward carb.

Sounds like a problem with the plunger.  What happens if you swap plungers
front/rear?

> The trouble is, that even with the mixture adjusting nut screwed
> totally upwards it's still far too rich.

Several possibilities.  One is that the float valve is leaking a bit, and
letting the fuel level go too high at idle.

Another is that the jet and/or needle are worn.  This can be almost
impossible to detect without special tools, easiest diagnosis is to replace
them with known good ones (for example, swap with the other carb).  Even
brand new components are sometimes wrong.

Also possible the carb is not assembled properly, or the upper gland is
damaged, etc.  There is a brass sealing washer between the upper half of the
jet bearing and the carb body that is sometimes left out and can allow fuel
to bypass the jet and leak into the throat.

But first you need to solve whatever is keeping the piston from landing with
a click.  It's impossible to set the mixture correctly if the piston doesn't
move freely, as any binding will change the air velocity through the venture
and upset the mixture.

As a side comment, on my TR3A carbs (now mounted on the TR3), there is
enough play in the fit between the domes and the body to affect the needle
centering.  To get a repeatable position (so I can R&R the dome without
having to recenter), I lightly turn the dome clockwise against the screws
while tightening them.

-- Randall

---

From: [email-masked]
Date: Mon, 1 Aug 2016 13:16:20 +0000 (UTC)

VERY odd. I had exactly the same experience this weekend.  Colortune shows yellow and no amount of adjustment changed it. Checked to see the needle seat is flush, so should be lean, but is still rich.  Concluded it's likely worn needles/seats.  Have probably 75,000 miles on these carbs, so figure it's time to put new seats and needles in, and maybe do the floats and valves while I'm in there.  

Terry Smith, '59 TR3A
New Hampshire

----- Original Message -----
From: "David Griffiths" <[email-masked]>
To: "Triumph_send_message" <[email-masked]>
Sent: Sunday, July 31, 2016 4:33:41 PM
Subject: [TR] TR3. Fuel mixture too rich.

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: Geo Hahn <[email-masked]>
Date: Mon, 1 Aug 2016 06:35:59 -0700

--===============7200052848195324543==

--001a113df31a47285c053902ae22
Content-Transfer-Encoding: quoted-printable

Dave -

One thing you might try -- I believe the pistons and carb bodies are
supposed to be a matched set, i.e. you are not supposed to swap them.  But
not knowing what might have occurred in the past you could see what the
pistons behave like if you do swap them between the two carbs.

The metal piece you describe sounds like a heat shield and the rear carb
has a bit of a leak.

As for difficulty leaning the mix on one carb - you might want to verify
the fuel level in the bowls and assure the valves are not sticking and the
floats have not gotten sodden with fuel.  A length of thin wire bent into
an 'L' can be slipped alongside a float and turned to catch it and lift it
out.  Then you can shake the float and listen to hear if fuel has gotten
inside.

Geo

On Sun, Jul 31, 2016 at 1:33 PM, David Griffiths <[email-masked]> wrote:

> Hello all. I would welcome some advice on one of the carbs on my TR3,
> #15005. It=E2=80=99s primarily the rear one that is giving me trouble.
>
> The car has been running too rich for a long while and I decided to sort
> it out on the weekend. I took the air filters off. The first thing of
> interest was a difference in the behaviour of the two pistons. Both carbs
> have damper oil in them. The piston of the front carb was pretty hard to
> push up - I pushed a good way, and when I let go it fell quickly down to
> the bottom with a satisfying metallic thud. The rear piston didn=E2=80=99=
t offer
> damper, it fell quickly and with the same =E2=80=9Cclack=E2=80=9D as the =
forward carb. So
> it=E2=80=99s centering properly I think. I removed the chamber, spring an=
d piston
> and cleaned them carefully, and put them back in, but still exactly the
> same behaviour. Both carbs have the same damper oil. So that is one thing
> that puzzles me.
>
> The front carb is running a bit rich - it shows yellow on the Gunson
> colortune, but the plugs are ok and the rpm does not increase to speak of
> when I lift the piston a little.
> The rear carb, judged by the thick, black layer of soot on the plugs, is =
a
> lot worse. When I lift the piston the revs increase noticeably and stay
> there. The trouble is, that even with the mixture adjusting nut screwed
> totally upwards it=E2=80=99s still far too rich. The car may be sucking a=
 bit of
> air along the throttle shaft, but this should if anything lean out the mi=
x.
>
> There is one more thing that might be important, but I haven=E2=80=99t re=
searched
> it up yet. Just under each carb there is some kind of metal contact with
> the exhaust manifold, a kind of metal buttress or similar. It was hard to
> get a good look at it today. Well this is wet on the rear one and dry on
> the front one. I can=E2=80=99t say more just yet until I get a better loo=
k at this
> area. There is some smoke wifting up from that area after the metal heats
> up, but it doesn=E2=80=99t smell like burning fuel or oil.
>
> The car runs very well and I think that the rest of the motor is more or
> less properly adjusted. Valves are good, breaker gap is correct, plugs ar=
e
> new and gap correct. Timing is ok. Coil I have not checked, but the car
> runs and idles fine.
>
> So there it is. One problem - mixture too rich even with nut screwed up t=
o
> the max. One maybe problem - piston of same (rear) carb falls slowly.
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/triumphs/[email-masked]
>

--001a113df31a47285c053902ae22
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div>Dave -</div><div><br></div><div>One thing you might t=
ry -- I believe the pistons and carb bodies are supposed to be a matched se=
t, i.e. you are not supposed to swap them.=C2=A0 But not knowing what might=
 have occurred in the past you could see what the pistons behave like if yo=
u do swap them between the two carbs.</div><div><br></div><div>The metal pi=
ece you describe sounds like a heat shield and the rear carb has a bit of a=
 leak.</div><div><br></div><div>As for difficulty leaning the mix on one ca=
rb - you might=C2=A0want to verify the fuel level in the bowls and assure t=
he valves are not sticking and the floats have not gotten sodden with fuel.=
=C2=A0 A length of thin wire bent into an &#39;L&#39; can be slipped alongs=
ide a float and turned to catch it and lift it out.=C2=A0 Then you can shak=
e the float and listen to hear if fuel has gotten inside.</div><div><br></d=
iv><div>Geo</div></div><div class=3D"gmail_extra"><br><div class=3D"gmail_q=
uote">On Sun, Jul 31, 2016 at 1:33 PM, David Griffiths <span dir=3D"ltr">&l=
t;<a href=3D"mailto:[email-masked]" target=3D"_blank">[email-masked]</a>&=
gt;</span> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 =
0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello all. I would welc=
ome some advice on one of the carbs on my TR3, #15005. It=E2=80=99s primari=
ly the rear one that is giving me trouble.<br>
<br>
The car has been running too rich for a long while and I decided to sort it=
 out on the weekend. I took the air filters off. The first thing of interes=
t was a difference in the behaviour of the two pistons. Both carbs have dam=
per oil in them. The piston of the front carb was pretty hard to push up - =
I pushed a good way, and when I let go it fell quickly down to the bottom w=
ith a satisfying metallic thud. The rear piston didn=E2=80=99t offer the sa=
me resistance to being manually displaced upward. It was easier to push up,=
 and when I let go of it, it fell more slowly down and not with a metal to =
metal click - more a soft noise. However, when I removed the damper, it fel=
l quickly and with the same =E2=80=9Cclack=E2=80=9D as the forward carb. So=
 it=E2=80=99s centering properly I think. I removed the chamber, spring and=
 piston and cleaned them carefully, and put them back in, but still exactly=
 the same behaviour. Both carbs have the same damper oil. So that is one th=
ing that puzzles me.<br>
<br>
The front carb is running a bit rich - it shows yellow on the Gunson colort=
une, but the plugs are ok and the rpm does not increase to speak of when I =
lift the piston a little.<br>
The rear carb, judged by the thick, black layer of soot on the plugs, is a =
lot worse. When I lift the piston the revs increase noticeably and stay the=
re. The trouble is, that even with the mixture adjusting nut screwed totall=
y upwards it=E2=80=99s still far too rich. The car may be sucking a bit of =
air along the throttle shaft, but this should if anything lean out the mix.=
<br>
<br>
There is one more thing that might be important, but I haven=E2=80=99t rese=
arched it up yet. Just under each carb there is some kind of metal contact =
with the exhaust manifold, a kind of metal buttress or similar. It was hard=
 to get a good look at it today. Well this is wet on the rear one and dry o=
n the front one. I can=E2=80=99t say more just yet until I get a better loo=
k at this area. There is some smoke wifting up from that area after the met=
al heats up, but it doesn=E2=80=99t smell like burning fuel or oil.<br>
<br>
The car runs very well and I think that the rest of the motor is more or le=
ss properly adjusted. Valves are good, breaker gap is correct, plugs are ne=
w and gap correct. Timing is ok. Coil I have not checked, but the car runs =
and idles fine.<br>
<br>
So there it is. One problem - mixture too rich even with nut screwed up to =
the max. One maybe problem - piston of same (rear) carb falls slowly.<br>
<br>
Very grateful for any suggestions,<br>
Dave<br>
<br>
** <a href=3D"mailto:[email-masked]">[email-masked]</a> *=
*<br>
<br>
=3D"noreferrer">http://www.team.net/donate.html</a><br>
Archive: <a href=3D"http://www.team.net/archive" target=3D"_blank" rel=3D"n=
oreferrer">http://www.team.net/archive</a><br>
Forums: <a href=3D"http://www.team.net/forums" target=3D"_blank" rel=3D"nor=
eferrer">http://www.team.net/forums</a><br>
hs/[email-masked]" target=3D"_blank" rel=3D"noreferrer">http://autox.=
team.net/mailman/options/triumphs/[email-masked]</a><br>
</blockquote></div><br></div>

--001a113df31a47285c053902ae22--

--===============7200052848195324543==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--===============7200052848195324543==--

---

From: Darrell Walker <[email-masked]>
Date: Mon, 01 Aug 2016 20:33:58 -0700

> On Aug 1, 2016, at 5:55 AM, [email-masked] <[email-masked]> wrote:
> 
> I would pull the pistons and dampers again and double check for any obstructions, they should act equally.

Another quick test would be to swap the damper rods, and see if that changes the behavior of the piston drop.

-Darrell

---

From: [email-masked]
Date: Sun, 7 Aug 2016 12:48:25 +0000 (UTC)

Hello, everyone.  Question.  Ever since I hit a dear last year, I've had a rap at low RPM followed by a rattling at higher RPMS, that goes away or can change pitch seemingly at random.  I don't think it's wrist pins or bottom end bearings, since normally that is a knock that stays a knock rather than become a rattle, though I could be wrong.  More curious, what does it sound like if the timing chain tensioner were to break off.  Can the chain rap against anything in there?  Or what does a sticking lifter sound like?

Terry Smith, '59 TR3A
New Hampshire

---

From: George Richardson <[email-masked]>
Date: Sun, 7 Aug 2016 09:29:07 -0400

Check the water pump pulley. Mine was loose for years before I found it.

George Richardson
Key Men - Keys for Classics
www.key-men.com

1957 Triumph TR3
1961 Jaguar Mark 2
1975 Triumph TR6
1997 Land Rover Discovery

On 8/7/2016 8:48 AM, [email-masked] wrote:
> Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]
>

---

From: "[email-masked]" <[email-masked]>
Date: Sun, 7 Aug 2016 13:38:03 -0500

Fan could be making intermittent contact somewhere with different sounds at different speeds.  If you do suspect a stuck valve that should be easy enough to check by removing the valve cover, shake and observe.  

I should think that if the timing chain tensioner went that it would jump time and not run well at all, but there are greater minds than mine that can weigh in on that possibility.  

Good luck,
Bill B 

TS30800L

Sent from my UNIVAC

On Aug 7, 2016, at 7:48 AM, [email-masked] wrote:

Terry Smith, '59 TR3A
New Hampshire

---

From: [email-masked]
Date: Sun, 7 Aug 2016 21:48:32 +0000 (UTC)

Spent the day rebuilding the carbs on the TR3.  Great video on You Tube showing step by step every little move. Easy Peazy.  Only thing it forgot was how to replace the check valve in the fuel reservoir.  Put it all together and started up and kept idle.  Will check mixture next weekend.

Interesting thing.  The mixture nuts had gotten too tight to adjust.  They just spun in the assembly while in the car, meaning attempts to adjust the mixture before the rebuild wasn't happening.  Broke them free and cleaned them, work fine.  

Amazing how simple these little carburetors are.  

Question.  When I think it was Apple Hydraulics rebuilt these the first time, they installed brass bushings for the throttle shafts.  Still fine, those.  But at some point, when they wear, I'll want to replace the bushings.  Is there a standard source for them?

Terry Smith, '59 TR3A
New Hampshire

---

From: [email-masked]
Date: Sun, 7 Aug 2016 21:51:01 +0000 (UTC)

Checked engine mounts with a crowbar, nothing moves.  Checked the radiator, nothing moves.  Looked under the valve cover, all seems normal.  
 
Winter before last I rebuilt a spare engine.  This winter, I'll begin dismantling this one, starting with the top end and timing areas to see what's up.  

Thank you, everyone, for your suggestions.

Terry

---

From: Geo Hahn <[email-masked]>
Date: Sun, 7 Aug 2016 15:27:41 -0700

--===============4145410710151332608==

--001a113e2110da7af3053982ce6c

--001a113e2110da7af0053982ce6b
Content-Transfer-Encoding: quoted-printable

On Sun, Aug 7, 2016 at 11:38 AM, [email-masked] <[email-masked]> wrote:

... I should think that if the timing chain tensioner went that it would
> jump time and not run well at all, but there are greater minds than mine
> that can weigh in on that possibility.
>

Timing tensioner failure results in a somewhat high-pitched chatter that
should be easily isolated as coming from behind the timing chain cover.  A
broken tensioner does not change the timing - engine runs fine like that,
but in short order the broken tensioner will start to dig a hole in the
cover.

=E2=80=8B
Geo

--001a113e2110da7af0053982ce6b
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div class=3D"gmail_extra"><div class=3D"gmail_quote">On S=
un, Aug 7, 2016 at 11:38 AM, <a href=3D"mailto:[email-masked]">Wbeech@fla=
sh.net</a> <span dir=3D"ltr">&lt;<a href=3D"mailto:[email-masked]" target=
=3D"_blank">[email-masked]</a>&gt;</span> wrote:</div><div class=3D"gmail=
_quote"><br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px=
 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-=
width:1px;border-left-style:solid">...
I should think that if the timing chain tensioner went that it would jump t=
ime and not run well at all, but there are greater minds than mine that can=
 weigh in on that possibility.<br></blockquote><div><br></div><div>Timing t=
ensioner failure results in a somewhat high-pitched chatter that should be =
easily isolated as coming from behind the timing chain cover.=C2=A0 A broke=
n=C2=A0tensioner does not change the timing -=C2=A0engine runs fine like th=
at, but in short order the broken tensioner will start to dig a hole in the=
 cover.</div><div><br></div><div><img width=3D"471" height=3D"314" src=3D"c=
id:ii_irl6i8xt0_156671d6b654b0e5"><br>=E2=80=8B</div><div>Geo</div></div></=
div>

--001a113e2110da7af0053982ce6b--

--001a113e2110da7af3053982ce6c
Content-Disposition: inline; filename="Timing Cover.JPG"
Content-Transfer-Encoding: base64
Content-ID: <ii_irl6i8xt0_156671d6b654b0e5>

--001a113e2110da7af3053982ce6c--

--===============4145410710151332608==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--===============4145410710151332608==--

---

From: "Randall" <[email-masked]>
Date: Mon, 8 Aug 2016 10:08:48 -0400

> but in short order the broken tensioner will start to dig a hole in the

Probably depends on where it breaks.  Mine broke right next to the pivot, so
essentially the entire tensioner slid to the bottom and wasn't rubbing
against the cover.  

There was a noise, but it was more of a ringing, showed up only
intermittently and only at low rpm (just above idle).  It also wasn't very
loud, I might not have noticed it if I hadn't been driving slowly in an area
with no other traffic.

I don't know if the noise was from the broken tensioner, or the crank hub
that was loose on the crankshaft, but I'm inclined to think it was the hub.
I only discovered the tensioner because I decided to change the seal while
replacing the hub.

But as Geo said, it didn't jump time and ran fine.  I drove another 200
miles or so from when I first noticed the noise until I pulled the timing
cover.

-- Randall

---

From: "Randall" <[email-masked]>
Date: Mon, 8 Aug 2016 10:18:11 -0400

> Question.  When I think it was Apple Hydraulics rebuilt these the first
> time, they installed brass bushings for the throttle shafts.  Still fine,
> those.  But at some point, when they wear, I'll want to replace the
> bushings.  Is there a standard source for them?

I got mine at McMaster-Carr.  The standard size was just a bit too long, but
the extra length didn't seem to hurt anything, so I didn't bother trimming
them.  (Sorry, don't have the size info handy.)

Unfortunately, the shafts wear about as fast as the bushings do.  You can
also buy bare shaft from MMC, but it won't be cut for the throttle plates
and screws that secure them.  I had some NORS shafts on hand, so I used
those.  (Still had to drill them for the idle stop levers, still didn't get
the holes in quite the right spot.)

The whole "brass on brass" thing seems a bit iffy to me; I may try using a
steel shaft next time (if there is a next time for me, I don't drive the car
as much now that I'm retired) and see if that holds up better.

-- Randall

---

From: [email-masked]
Date: Mon, 8 Aug 2016 22:07:35 +0000 (UTC)

'S'cuse the presumption, Randall, but I thought you were too young and beautiful to retire?

----- Original Message -----
From: "Randall" <[email-masked]>
To: [email-masked], "triumphs" <[email-masked]>
Sent: Monday, August 8, 2016 10:18:11 AM
Subject: RE: [TR] Rattling

-- Randall

---

From: "Randall" <[email-masked]>
Date: Tue, 9 Aug 2016 23:33:50 -0400

> 'S'cuse the presumption, Randall, but I thought you were too young and

Guess it's a good thing no one told me those were requirements!

I'm plenty un-beautiful enough, but with my last name, I'll always be Young.

-- Randall (Young)