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Re: [Healeys] Another backfiring question

To: "'Bob Spidell'" <bspidell@comcast.net>, <healeys@autox.team.net>
Subject: Re: [Healeys] Another backfiring question
From: "John Spaur" <jmsdarch@sbcglobal.net>
Date: Fri, 29 Jan 2021 08:49:05 -0800
Delivered-to: mharc@autox.team.net
Delivered-to: healeys@autox.team.net
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I use a Uni-Sync too but I also used a hose when I recently installed =
new HS4 tricarbs. The hose works well too but it does not give you an =
indication of air volume, just equal noise.

=20

John

=20

From: Healeys [mailto:healeys-bounces@autox.team.net] On Behalf Of Bob =
Spidell
Sent: Friday, January 29, 2021 8:18 AM
To: healeys@autox.team.net
Subject: Re: [Healeys] Another backfiring question

=20

I dunno if it can cause high RPM backfiring (I think it could), but the =
airflow on all (2-3) carbs has to be the same--or, at least, very =
close--at all throttle positions. This has to be checked off-idle, =
obviously, but if it's good at, say, 2,500RPM it should be good at all =
speeds; if not, you have to disconnect the throttle connect shaft to set =
them. I suppose a crack Brit-car mechanic can test with the recommended =
'hose-in-the-ear' technique--my ear hose is collecting dust =
somewhere--but I use a Uni-Syn.

To paraphrase the TV commercial we've all (probably) seen a thousand =
times: "If you don't have a carburettor synchronizer, get one."

Bob

On 1/29/2021 6:13 AM, healeyguy--- via Healeys wrote:

Len and Listers

Pushing the pin up to lift the piston is the start of the "test the =
mixture setting" exercise. You begin the push, ever so slightly,  and =
listen to the idling engine. The idle goes up.  What do you do next? You =
continue to raise the pin  to see what happens. If the idle continues to =
rise you know you are in a rich condition. If the idle stops going up =
and starts to drop off the mixture is pretty close. If the idle does not =
increase from the start you usually assume you are in a lean condition.  =
This gets the carb mixture close at idle which in theory means the carb =
is going to operate throughout the RPM range. =20

=20

There is one other assumption here, that being that the carbs is in the =
same condition as new mounted on an engine operating as new. That is =
when allot of other stuff comes into play.  The carb float bowl items, =
needle/seat and float level  must be set correctly. Float must not be =
leaking thus making it sink. Carb must have the correct main needle and =
jet and they have to be installed and adjusted correctly. Flutter at =
high RPM may indicate that the piston spring in the suction chamber is =
weak or the incorrect spring installed. Ignition timing and condition =
and setting of ignition points.

The list goes on and on......

P



-----Original Message-----
<DrBerkowitz@hotmail.com>
Subject: [Healeys] Another backfiring question

Hi all

=20

Just finished repairing and reinstalling the carburetors on my BJ7. I =
thought I had everything adjusted properly. According to my Haynes =
Manuel the engine speed should increase slightly when you lift the =
piston a very small amount. Mine does that.  My dwell angle is where it =
needs to be and the car starts and idles nicely. Also sounds beautiful =
when I punch the accelerator linkages. The problem is that when I get it =
up to 60-70 mph I get what sounds like backfiring into my carburetors. =
Also sounds like it doesn=E2=80=99t have a whole lot left in the tank, =
so to speak. Does that sound like I am running too rich or too lean?=20

=20

Len Berkowitz=20

=20

=20

=20


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</o:shapelayout></xml><![endif]--></head><body lang=3DEN-US link=3Dblue =
vlink=3Dpurple><div class=3DWordSection1><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'=
>I use a Uni-Sync too but I also used a hose when I recently installed =
new HS4 tricarbs. The hose works well too but it does not give you an =
indication of air volume, just equal noise.<o:p></o:p></span></p><p =
class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'=
><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'=
>John<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'=
><o:p>&nbsp;</o:p></span></p><div><div =
style=3D'border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in =
0in 0in'><p class=3DMsoNormal><b><span =
style=3D'font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span><=
/b><span style=3D'font-size:11.0pt;font-family:"Calibri",sans-serif'> =
Healeys [mailto:healeys-bounces@autox.team.net] <b>On Behalf Of </b>Bob =
Spidell<br><b>Sent:</b> Friday, January 29, 2021 8:18 AM<br><b>To:</b> =
healeys@autox.team.net<br><b>Subject:</b> Re: [Healeys] Another =
backfiring question<o:p></o:p></span></p></div></div><p =
class=3DMsoNormal><o:p>&nbsp;</o:p></p><p class=3DMsoNormal =
style=3D'margin-bottom:12.0pt'>I dunno if it can cause high RPM =
backfiring (I think it could), but the airflow on all (2-3) carbs has to =
be the same--or, at least, very close--at all throttle positions. This =
has to be checked off-idle, obviously, but if it's good at, say, =
2,500RPM it should be good at all speeds; if not, you have to disconnect =
the throttle connect shaft to set them. I suppose a crack Brit-car =
mechanic can test with the recommended 'hose-in-the-ear' technique--my =
ear hose is collecting dust somewhere--but I use a Uni-Syn.<br><br>To =
paraphrase the TV commercial we've all (probably) seen a thousand times: =
&quot;If you don't have a carburettor synchronizer, get =
one.&quot;<br><br>Bob<o:p></o:p></p><div><p class=3DMsoNormal>On =
1/29/2021 6:13 AM, healeyguy--- via Healeys =
wrote:<o:p></o:p></p></div><blockquote =
style=3D'margin-top:5.0pt;margin-bottom:5.0pt'><div><div><div =
id=3Dyiv9115048286><div><p class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>Len=
 and Listers<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>Pus=
hing the pin up to lift the piston is the start of the &quot;test the =
mixture setting&quot; exercise. You begin the push, ever so =
slightly,&nbsp; and listen to the idling engine. The idle goes up.&nbsp; =
What do you do next? You continue to raise the pin&nbsp; to see what =
happens. If the idle continues to rise you know you are in a rich =
condition. If the idle stops going up and starts to drop off the mixture =
is pretty close. If the idle does not increase from the start you =
usually assume you are in a lean condition.&nbsp; This gets the carb =
mixture close at idle which in theory means the carb is going to operate =
throughout the RPM range.&nbsp;&nbsp;<o:p></o:p></span></p></div><div><p =
class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'><o:=
p>&nbsp;</o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>The=
re is one other assumption here, that being that the carbs is in the =
same condition as new mounted on an engine operating as new. That is =
when allot of other stuff comes into play.&nbsp; The carb float bowl =
items, needle/seat and float level&nbsp; must be set correctly. Float =
must not be leaking thus making it sink. Carb must have the correct main =
needle and jet and they have to be installed and adjusted =
correctly.&nbsp;Flutter at high RPM may indicate that the piston spring =
in the suction chamber is weak or the incorrect spring installed. =
Ignition timing and condition and setting of ignition =
points.<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>The=
 list goes on and on......<o:p></o:p></span></p></div><div><p =
class=3DMsoNormal style=3D'margin-bottom:12.0pt'><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>P<b=
r><br><o:p></o:p></span></p><div><p class=3DMsoNormal =
style=3D'margin-bottom:12.0pt'><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>---=
--Original Message-----<br>From: Leonard Berkowitz <a =
href=3D"mailto:DrBerkowitz@hotmail.com";>&lt;DrBerkowitz@hotmail.com&gt;</=
a><br>Subject: [Healeys] Another backfiring =
question<o:p></o:p></span></p><div id=3Dyiv9115048286yqt58392><div =
id=3Dyiv9115048286><div><div><p class=3DMsoNormal><span =
style=3D'font-family:"Calibri",sans-serif;color:black'>Hi =
all<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-family:"Calibri",sans-serif;color:black'><o:p>&nbsp;</o:p><=
/span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-family:"Calibri",sans-serif;color:black'>Just finished =
repairing and reinstalling the carburetors on my BJ7. I thought I had =
everything adjusted properly. According to my Haynes Manuel the engine =
speed should increase slightly when you lift the piston a very small =
amount. Mine does that. &nbsp;My dwell angle is where it needs to be and =
the car starts and idles nicely. Also sounds beautiful when I punch the =
accelerator linkages. The problem is that when I get it up to 60-70 mph =
I get what sounds like backfiring into my carburetors. Also sounds like =
it doesn=E2=80=99t have a whole lot left in the tank, so to speak. Does =
that sound like I am running too rich or too =
lean?&nbsp;<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-family:"Calibri",sans-serif;color:black'><o:p>&nbsp;</o:p><=
/span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-family:"Calibri",sans-serif;color:black'>Len =
Berkowitz&nbsp;<o:p></o:p></span></p></div></div></div></div><p =
class=3DMsoNormal style=3D'margin-bottom:12.0pt'><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:black'><o:=
p>&nbsp;</o:p></span></p></div></div></div></div></div><p =
class=3DMsoNormal><o:p>&nbsp;</o:p></p></blockquote><p =
class=3DMsoNormal><o:p>&nbsp;</o:p></p></div></body></html>
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