Jetting suggestions for 34 PICT on 1776

Hello,

I posted a fem months back, but unfortunately cannot add to that post.
I have a 1776 motor ith svda distributor and 34 pict carb. I had
pulled the motor over the summer to freshen the tinware a bit, replace
a rear apron, etc. Now that i have it running again, i wish to get the
cold idle dialed in.

When I start it cold the choke does come on, and the exhaust does puff
some black smoke. It really runs slowly at about 600 or so rpm (not
quicker like it should with a choke on) Once i drive it 5 minutes or
so, things improve and it idles about 900. It gets "ok" mileage i
would say about 20 or so to a gallon. The timing is set to 32 degrees
total advance.

I figure someone out there on this list must have dialed in a similar
setup and can help me.

vgonman wrote:
> Hello,
>
> I posted a fem months back, but unfortunately cannot add to that post.
> I have a 1776 motor ith svda distributor and 34 pict carb. I had
> pulled the motor over the summer to freshen the tinware a bit, replace
> a rear apron, etc. Now that i have it running again, i wish to get the
> cold idle dialed in.
>
> When I start it cold the choke does come on, and the exhaust does puff
> some black smoke. It really runs slowly at about 600 or so rpm (not
> quicker like it should with a choke on) Once i drive it 5 minutes or
> so, things improve and it idles about 900. It gets "ok" mileage i
> would say about 20 or so to a gallon. The timing is set to 32 degrees
> total advance.
>
> I figure someone out there on this list must have dialed in a similar
> setup and can help me.


First thing, set your timing at 30-32 BTDC with the vacuum line
disconnected and the RPM up past the point of maximum mechanical
advance, say around 3000. Max advance should run up over 40 with
the line back on and when you bring up the RPM slowly. That extra
10 degrees are the benefit of an SVDA over an 009.

If your 34PICT carb is old, consider buying a new one. By the time
you get one of these rebushed, rebuilt, new solenoids, choke, etc,
it will cost close to what a new one runs and it will likely still have
some issues. If you can't get the neccessary 1.4-1.8CC/stroke on
the accel pump due to internal check-ball seat corrosion inside the
hidden passages, you will never solve hesitation problems. And the
choke may still get you issues even if you buy a new element. If
you do buy a new carb, get it from a supplier who will stand behind
the sale such as www.aircooled.net - there have been more than a
few reject's out there and many places wouldn't hesistate to put it
back on the shelf and sell it again.

Jetting isn't rocket science. 55 idle at sea level should work even
on a 1776. If the idle RPM peaks at 2-3 1/2 turns out, you're OK.
If it takes 4 1/2 to 6 turns to peak, go up a size or (1/2 size if you
can find them - rare!). Main jet should be around the 130-135 area
to start at sea level. Air correction 75 to 125 and these are changed
only to richen up or lean out the engine at a certain RPM range
when you're running on the main. Check out the articles at this
excellent website for more detailed information;

http://www.vw-resource.com

It has all you need to properly adjust everything on your carb
including the choke.

I am diving into it today. I will start by verifying timing, and jet
size.

Raymond T. Lowe wrote:
> vgonman wrote:
> > Hello,
> >
> > I posted a fem months back, but unfortunately cannot add to that post.
> > I have a 1776 motor ith svda distributor and 34 pict carb. I had
> > pulled the motor over the summer to freshen the tinware a bit, replace
> > a rear apron, etc. Now that i have it running again, i wish to get the
> > cold idle dialed in.
> >
> > When I start it cold the choke does come on, and the exhaust does puff
> > some black smoke. It really runs slowly at about 600 or so rpm (not
> > quicker like it should with a choke on) Once i drive it 5 minutes or
> > so, things improve and it idles about 900. It gets "ok" mileage i
> > would say about 20 or so to a gallon. The timing is set to 32 degrees
> > total advance.
> >
> > I figure someone out there on this list must have dialed in a similar
> > setup and can help me.
>
>
> First thing, set your timing at 30-32 BTDC with the vacuum line
> disconnected and the RPM up past the point of maximum mechanical
> advance, say around 3000. Max advance should run up over 40 with
> the line back on and when you bring up the RPM slowly. That extra
> 10 degrees are the benefit of an SVDA over an 009.
>
> If your 34PICT carb is old, consider buying a new one. By the time
> you get one of these rebushed, rebuilt, new solenoids, choke, etc,
> it will cost close to what a new one runs and it will likely still have
> some issues. If you can't get the neccessary 1.4-1.8CC/stroke on
> the accel pump due to internal check-ball seat corrosion inside the
> hidden passages, you will never solve hesitation problems. And the
> choke may still get you issues even if you buy a new element. If
> you do buy a new carb, get it from a supplier who will stand behind
> the sale such as www.aircooled.net - there have been more than a
> few reject's out there and many places wouldn't hesistate to put it
> back on the shelf and sell it again.
>
> Jetting isn't rocket science. 55 idle at sea level should work even
> on a 1776. If the idle RPM peaks at 2-3 1/2 turns out, you're OK.
> If it takes 4 1/2 to 6 turns to peak, go up a size or (1/2 size if you
> can find them - rare!). Main jet should be around the 130-135 area
> to start at sea level. Air correction 75 to 125 and these are changed
> only to richen up or lean out the engine at a certain RPM range
> when you're running on the main. Check out the articles at this
> excellent website for more detailed information;
>
> http://www.vw-resource.com
>
> It has all you need to properly adjust everything on your carb
> including the choke.

Here are results from yesterday. Valves were fine, I then checked for
any intake leaks. None were detected, even around throttle shaft. So,
I let it warm up, and set the timing to 32 degrees full advance. I
have a 52.5 idle jet in it, so it took about 4 1/2 turns to get max rpm
( thru a tach on my timing light).

Maybe someone can help me understand this volume control screw/idle
jet. I believe the volume control screw lets in more air into idle
circuit as it is opened. Now, my question is, why is my car so rich at
cold idle? I have a 52.5 idle jet, and my header pipe points to the
ground, so i can see a sooty spot on the ground. The car does not
speed up when cold and choke engaged. It seems if i go up on idle jet,
it will get more fuel and be more sooty? But then i look at my 1600
and it runs a 55 idle jet and operates as it should.

Any advice is greatly appreciated.

vgonman wrote:
> I am diving into it today. I will start by verifying timing, and jet
> size.
>
> Raymond T. Lowe wrote:
> > vgonman wrote:
> > > Hello,
> > >
> > > I posted a fem months back, but unfortunately cannot add to that post.
> > > I have a 1776 motor ith svda distributor and 34 pict carb. I had
> > > pulled the motor over the summer to freshen the tinware a bit, replace
> > > a rear apron, etc. Now that i have it running again, i wish to get the
> > > cold idle dialed in.
> > >
> > > When I start it cold the choke does come on, and the exhaust does puff
> > > some black smoke. It really runs slowly at about 600 or so rpm (not
> > > quicker like it should with a choke on) Once i drive it 5 minutes or
> > > so, things improve and it idles about 900. It gets "ok" mileage i
> > > would say about 20 or so to a gallon. The timing is set to 32 degrees
> > > total advance.
> > >
> > > I figure someone out there on this list must have dialed in a similar
> > > setup and can help me.
> >
> >
> > First thing, set your timing at 30-32 BTDC with the vacuum line
> > disconnected and the RPM up past the point of maximum mechanical
> > advance, say around 3000. Max advance should run up over 40 with
> > the line back on and when you bring up the RPM slowly. That extra
> > 10 degrees are the benefit of an SVDA over an 009.
> >
> > If your 34PICT carb is old, consider buying a new one. By the time
> > you get one of these rebushed, rebuilt, new solenoids, choke, etc,
> > it will cost close to what a new one runs and it will likely still have
> > some issues. If you can't get the neccessary 1.4-1.8CC/stroke on
> > the accel pump due to internal check-ball seat corrosion inside the
> > hidden passages, you will never solve hesitation problems. And the
> > choke may still get you issues even if you buy a new element. If
> > you do buy a new carb, get it from a supplier who will stand behind
> > the sale such as www.aircooled.net - there have been more than a
> > few reject's out there and many places wouldn't hesistate to put it
> > back on the shelf and sell it again.
> >
> > Jetting isn't rocket science. 55 idle at sea level should work even
> > on a 1776. If the idle RPM peaks at 2-3 1/2 turns out, you're OK.
> > If it takes 4 1/2 to 6 turns to peak, go up a size or (1/2 size if you
> > can find them - rare!). Main jet should be around the 130-135 area
> > to start at sea level. Air correction 75 to 125 and these are changed
> > only to richen up or lean out the engine at a certain RPM range
> > when you're running on the main. Check out the articles at this
> > excellent website for more detailed information;
> >
> > http://www.vw-resource.com
> >
> > It has all you need to properly adjust everything on your carb
> > including the choke.

vgonman wrote:
> Here are results from yesterday. Valves were fine, I then checked for
> any intake leaks. None were detected, even around throttle shaft. So,
> I let it warm up, and set the timing to 32 degrees full advance. I
> have a 52.5 idle jet in it, so it took about 4 1/2 turns to get max rpm
> ( thru a tach on my timing light).
>
> Maybe someone can help me understand this volume control screw/idle
> jet. I believe the volume control screw lets in more air into idle
> circuit as it is opened. Now, my question is, why is my car so rich at
> cold idle? I have a 52.5 idle jet, and my header pipe points to the
> ground, so i can see a sooty spot on the ground. The car does not
> speed up when cold and choke engaged. It seems if i go up on idle jet,
> it will get more fuel and be more sooty? But then i look at my 1600
> and it runs a 55 idle jet and operates as it should.
>
> Any advice is greatly appreciated.
>


Volume control screw allows air to bypass the throttle plate. The
position of the throttle plate is critical to the progression ports and
the vacuum signal to the distributor. And since all engines wind up
being slightly different, by using an adjustable bypass circuit, you
don't have to disturb the position of this plate to get an engine to
idle properly.

Change out the idle to 55. A 34PICT carb usually doesn't like
leaner-than-stock idle jets in my experience. 4 1/2 turns out
confirms this. Verify your fuel pressure with a gauge that reads
accurately at low pressures, say 0-15psi. 2 1/2 lbs of pressure
for a stock carb is a good target. Toss in a rebuild kit that has
a new needle valve if you suspect your fuel level is too high in
the bowl. Cause your symptoms sure point in this direction.
To cause soot on the ground, your getting wayyy too much
fuel and it isn't the idle jet.

Don't rule out a vacuum leak if your engine lumps along on 3
cylinders for a while when cold. I chased a demon in my engine
for longer than I care to admit and it turned out to be an intake
leak. I kept suspecting that but even ether didn't bring any change
to the idle speed. Turns out the leak was where the end casting
bolted to the head at a spot where pressurized air from the cooling
fan squirted out from the cylinder tin. In retrospect, maybe I
should have used one of those little red extension tubes to get the
spray concentrated right down into the crevice.


RT
--
E-mail=fullname,no initial-at-telus.net

Raymond,

Thanks for the info. I read this post AFTER I had tinkered for a
while, and here is what i discovered I swapped idle jet to 55 at
first, and there was no change. Then I went to a 45, and 2 to 2 1/2
was max idle. I drove it around the block, and performance seems
identical to the 52.5 jet. Odd, ain't it? It is pretty peppy, mind
you. Definately not a beater running on 3 for sure.

I think that you are dead on about maybe the needle/seat being worn.
Once the choke goes out, and i blip the throttle (at the engine) I see
a black waft of smoke and smell fuel. It is not dripping anywhere, so
it is being wasted out the exhaust. I thought, maybe too rich of main
jet, but that would not explain the soot hitting the ground at idle.

I think i will attempt a rebuild of this beast tomorrow. I will pick up
a carb kit and see what happens.


Raymond T. Lowe wrote:
> vgonman wrote:
> > Here are results from yesterday. Valves were fine, I then checked for
> > any intake leaks. None were detected, even around throttle shaft. So,
> > I let it warm up, and set the timing to 32 degrees full advance. I
> > have a 52.5 idle jet in it, so it took about 4 1/2 turns to get max rpm
> > ( thru a tach on my timing light).
> >
> > Maybe someone can help me understand this volume control screw/idle
> > jet. I believe the volume control screw lets in more air into idle
> > circuit as it is opened. Now, my question is, why is my car so rich at
> > cold idle? I have a 52.5 idle jet, and my header pipe points to the
> > ground, so i can see a sooty spot on the ground. The car does not
> > speed up when cold and choke engaged. It seems if i go up on idle jet,
> > it will get more fuel and be more sooty? But then i look at my 1600
> > and it runs a 55 idle jet and operates as it should.
> >
> > Any advice is greatly appreciated.
> >
>
>
> Volume control screw allows air to bypass the throttle plate. The
> position of the throttle plate is critical to the progression ports and
> the vacuum signal to the distributor. And since all engines wind up
> being slightly different, by using an adjustable bypass circuit, you
> don't have to disturb the position of this plate to get an engine to
> idle properly.
>
> Change out the idle to 55. A 34PICT carb usually doesn't like
> leaner-than-stock idle jets in my experience. 4 1/2 turns out
> confirms this. Verify your fuel pressure with a gauge that reads
> accurately at low pressures, say 0-15psi. 2 1/2 lbs of pressure
> for a stock carb is a good target. Toss in a rebuild kit that has
> a new needle valve if you suspect your fuel level is too high in
> the bowl. Cause your symptoms sure point in this direction.
> To cause soot on the ground, your getting wayyy too much
> fuel and it isn't the idle jet.
>
> Don't rule out a vacuum leak if your engine lumps along on 3
> cylinders for a while when cold. I chased a demon in my engine
> for longer than I care to admit and it turned out to be an intake
> leak. I kept suspecting that but even ether didn't bring any change
> to the idle speed. Turns out the leak was where the end casting
> bolted to the head at a spot where pressurized air from the cooling
> fan squirted out from the cylinder tin. In retrospect, maybe I
> should have used one of those little red extension tubes to get the
> spray concentrated right down into the crevice.
>
>
> RT
> --
> E-mail=fullname,no initial-at-telus.net

vgonman wrote:
> Raymond,
>
> Thanks for the info. I read this post AFTER I had tinkered for a
> while, and here is what i discovered I swapped idle jet to 55 at
> first, and there was no change. Then I went to a 45, and 2 to 2 1/2
> was max idle. I drove it around the block, and performance seems
> identical to the 52.5 jet. Odd, ain't it? It is pretty peppy, mind
> you. Definately not a beater running on 3 for sure.
>
> I think that you are dead on about maybe the needle/seat being worn.
> Once the choke goes out, and i blip the throttle (at the engine) I see
> a black waft of smoke and smell fuel. It is not dripping anywhere, so
> it is being wasted out the exhaust. I thought, maybe too rich of main
> jet, but that would not explain the soot hitting the ground at idle.
>
> I think i will attempt a rebuild of this beast tomorrow. I will pick up
> a carb kit and see what happens.

That's a good start but I would stress strongly that a fuel gauge is
a must-have. Maybe an industrial supplier or decent parts store
that carries Wika gauges. They're good quality and fairly cheap.


RT
--
E-mail=fullname,no initial-at-telus.net

My friend at the VW shop has a pressure gauge...I will test tomorrow
when i buy the kit.

Too much fuel pressure could for sure cause what i am experiencing,
too.

Raymond T. Lowe wrote:
> vgonman wrote:
> > Raymond,
> >
> > Thanks for the info. I read this post AFTER I had tinkered for a
> > while, and here is what i discovered I swapped idle jet to 55 at
> > first, and there was no change. Then I went to a 45, and 2 to 2 1/2
> > was max idle. I drove it around the block, and performance seems
> > identical to the 52.5 jet. Odd, ain't it? It is pretty peppy, mind
> > you. Definately not a beater running on 3 for sure.
> >
> > I think that you are dead on about maybe the needle/seat being worn.
> > Once the choke goes out, and i blip the throttle (at the engine) I see
> > a black waft of smoke and smell fuel. It is not dripping anywhere, so
> > it is being wasted out the exhaust. I thought, maybe too rich of main
> > jet, but that would not explain the soot hitting the ground at idle.
> >
> > I think i will attempt a rebuild of this beast tomorrow. I will pick up
> > a carb kit and see what happens.
>
> That's a good start but I would stress strongly that a fuel gauge is
> a must-have. Maybe an industrial supplier or decent parts store
> that carries Wika gauges. They're good quality and fairly cheap.
>
>
> RT
> --
> E-mail=fullname,no initial-at-telus.net

Pressure came in at 4 lbs., so a little high. I have a good rebuild
kit and will tackle tomorrow........

vgonman wrote:
> My friend at the VW shop has a pressure gauge...I will test tomorrow
> when i buy the kit.
>
> Too much fuel pressure could for sure cause what i am experiencing,
> too.
>
> Raymond T. Lowe wrote:
> > vgonman wrote:
> > > Raymond,
> > >
> > > Thanks for the info. I read this post AFTER I had tinkered for a
> > > while, and here is what i discovered I swapped idle jet to 55 at
> > > first, and there was no change. Then I went to a 45, and 2 to 2 1/2
> > > was max idle. I drove it around the block, and performance seems
> > > identical to the 52.5 jet. Odd, ain't it? It is pretty peppy, mind
> > > you. Definately not a beater running on 3 for sure.
> > >
> > > I think that you are dead on about maybe the needle/seat being worn.
> > > Once the choke goes out, and i blip the throttle (at the engine) I see
> > > a black waft of smoke and smell fuel. It is not dripping anywhere, so
> > > it is being wasted out the exhaust. I thought, maybe too rich of main
> > > jet, but that would not explain the soot hitting the ground at idle.
> > >
> > > I think i will attempt a rebuild of this beast tomorrow. I will pick up
> > > a carb kit and see what happens.
> >
> > That's a good start but I would stress strongly that a fuel gauge is
> > a must-have. Maybe an industrial supplier or decent parts store
> > that carries Wika gauges. They're good quality and fairly cheap.
> >
> >
> > RT
> > --
> > E-mail=fullname,no initial-at-telus.net

I think a 34 pict is too small for a 1776. I have a 1641 (groan) and it
can barely cope with it at higher revs. I'm running 55 idle and 132.5
main jet.

--Steve

vgonman wrote:
> I am diving into it today. I will start by verifying timing, and jet
> size.
>
> Raymond T. Lowe wrote:
>> vgonman wrote:
>>> Hello,
>>>
>>> I posted a fem months back, but unfortunately cannot add to that post.
>>> I have a 1776 motor ith svda distributor and 34 pict carb. I had
>>> pulled the motor over the summer to freshen the tinware a bit, replace
>>> a rear apron, etc. Now that i have it running again, i wish to get the
>>> cold idle dialed in.
>>>
>>> When I start it cold the choke does come on, and the exhaust does puff
>>> some black smoke. It really runs slowly at about 600 or so rpm (not
>>> quicker like it should with a choke on) Once i drive it 5 minutes or
>>> so, things improve and it idles about 900. It gets "ok" mileage i
>>> would say about 20 or so to a gallon. The timing is set to 32 degrees
>>> total advance.
>>>
>>> I figure someone out there on this list must have dialed in a similar
>>> setup and can help me.
>>
>> First thing, set your timing at 30-32 BTDC with the vacuum line
>> disconnected and the RPM up past the point of maximum mechanical
>> advance, say around 3000. Max advance should run up over 40 with
>> the line back on and when you bring up the RPM slowly. That extra
>> 10 degrees are the benefit of an SVDA over an 009.
>>
>> If your 34PICT carb is old, consider buying a new one. By the time
>> you get one of these rebushed, rebuilt, new solenoids, choke, etc,
>> it will cost close to what a new one runs and it will likely still have
>> some issues. If you can't get the neccessary 1.4-1.8CC/stroke on
>> the accel pump due to internal check-ball seat corrosion inside the
>> hidden passages, you will never solve hesitation problems. And the
>> choke may still get you issues even if you buy a new element. If
>> you do buy a new carb, get it from a supplier who will stand behind
>> the sale such as www.aircooled.net - there have been more than a
>> few reject's out there and many places wouldn't hesistate to put it
>> back on the shelf and sell it again.
>>
>> Jetting isn't rocket science. 55 idle at sea level should work even
>> on a 1776. If the idle RPM peaks at 2-3 1/2 turns out, you're OK.
>> If it takes 4 1/2 to 6 turns to peak, go up a size or (1/2 size if you
>> can find them - rare!). Main jet should be around the 130-135 area
>> to start at sea level. Air correction 75 to 125 and these are changed
>> only to richen up or lean out the engine at a certain RPM range
>> when you're running on the main. Check out the articles at this
>> excellent website for more detailed information;
>>
>> http://www.vw-resource.com
>>
>> It has all you need to properly adjust everything on your carb
>> including the choke.
>


--

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