34PICT3 question

Hey all:
I've been fiddling with my carb and everything works fine except when
I go to adjust the quantity on the accel. pump arm up to full, it
seems that the additional stroke length is just slack and that the
spring in the diaphram is not coming all the way back to actually give
a full stroke. I tried this on another carb and it seemed to do the
same thing.
A friend told me that he just adjusts to a point where there is no
lost motion and that that is the max stroke it's capable of.
Are these carbs actually capable of producing the "full stroke" as
indicated in the +/- markings on the lever or am I just mising
something with my procedure?
TIA
Bill.

Bill wrote:
> Hey all:
> I've been fiddling with my carb and everything works fine except when
> I go to adjust the quantity on the accel. pump arm up to full, it
> seems that the additional stroke length is just slack and that the
> spring in the diaphram is not coming all the way back to actually give
> a full stroke. I tried this on another carb and it seemed to do the
> same thing.
> A friend told me that he just adjusts to a point where there is no
> lost motion and that that is the max stroke it's capable of.
> Are these carbs actually capable of producing the "full stroke" as
> indicated in the +/- markings on the lever or am I just mising
> something with my procedure?
> TIA
> Bill.


The linkage is often badly worn, causing lots of free play. The rod that
goes from the lever to the pump wears, as does the eye it attaches to. I
weld them up and regrind the rod, then redrill the hole. After that the
pump kicks in immediately.

> The linkage is often badly worn, causing lots of free play. The rod that
> goes from the lever to the pump wears, as does the eye it attaches to. I
> weld them up and regrind the rod, then redrill the hole. After that the
> pump kicks in immediately.

Jan:
Sorry, I should've mentioned that one carb was new, one a nice old
Solex both with minimal linkage slack. What I'm saying is that with
a good carb on the workbench, properly set to the middle position and
injection occurring exactly when the throttle is opened, I adjust the
arm to the longest stroke setting. Now, injection quantity seems to
be the same, but only delayed by the new travel setting, which appears
to just pump air.
Is there a trick, such as x-number of full strokes, etc. to get that
diaphram to pull the full amount of fuel into the accel. pump chamber?
TIA
Bill.

Bill wrote:
>> The linkage is often badly worn, causing lots of free play. The rod that
>> goes from the lever to the pump wears, as does the eye it attaches to. I
>> weld them up and regrind the rod, then redrill the hole. After that the
>> pump kicks in immediately.
>
> Jan:
> Sorry, I should've mentioned that one carb was new, one a nice old
> Solex both with minimal linkage slack. What I'm saying is that with
> a good carb on the workbench, properly set to the middle position and
> injection occurring exactly when the throttle is opened, I adjust the
> arm to the longest stroke setting. Now, injection quantity seems to
> be the same, but only delayed by the new travel setting, which appears
> to just pump air.
> Is there a trick, such as x-number of full strokes, etc. to get that
> diaphram to pull the full amount of fuel into the accel. pump chamber?
> TIA
> Bill.


it should only take one stroke to fill it, regardless of how long the
stroke is. Is the ball checkvalve working properly in the fuel bowl?
Maybe you are getting some fuel backflow into the bowl. Weird, since you
should get that with the shorter strokes too, then.
I dunno.

Jan

When replacing the pump diaphragm I always tighten the 4 securing screws on
the pump cover with the spring allowed to extend the diaphragm as much as
possible. If you tension the screws with the spring compressed( ie if you
are holding down the pump) it can
limit the travel of the diaphragm.ie the diaphragm extends as much as it can
before being limited by the mechanism.
Jan, I liked that comment re welding up the holes, they do get enlongated.
I,m not a welder so is that the sort of thing a local machinery shop would
be able to do?. I,ve got visions of a local shop dragging out his mega-amp
welder and vapourising the thing!
Cheers
John



"Jan Andersson" > wrote in message
...
> Bill wrote:
>>> The linkage is often badly worn, causing lots of free play. The rod that
>>> goes from the lever to the pump wears, as does the eye it attaches to. I
>>> weld them up and regrind the rod, then redrill the hole. After that the
>>> pump kicks in immediately.
>>
>> Jan:
>> Sorry, I should've mentioned that one carb was new, one a nice old
>> Solex both with minimal linkage slack. What I'm saying is that with
>> a good carb on the workbench, properly set to the middle position and
>> injection occurring exactly when the throttle is opened, I adjust the
>> arm to the longest stroke setting. Now, injection quantity seems to
>> be the same, but only delayed by the new travel setting, which appears
>> to just pump air.
>> Is there a trick, such as x-number of full strokes, etc. to get that
>> diaphram to pull the full amount of fuel into the accel. pump chamber?
>> TIA
>> Bill.
>
>
> it should only take one stroke to fill it, regardless of how long the
> stroke is. Is the ball checkvalve working properly in the fuel bowl? Maybe
> you are getting some fuel backflow into the bowl. Weird, since you should
> get that with the shorter strokes too, then.
> I dunno.
>
> Jan

John wrote:
> When replacing the pump diaphragm I always tighten the 4 securing screws on
> the pump cover with the spring allowed to extend the diaphragm as much as
> possible. If you tension the screws with the spring compressed( ie if you
> are holding down the pump) it can
> limit the travel of the diaphragm.ie the diaphragm extends as much as it can
> before being limited by the mechanism.

Never thought of that, good point!


> Jan, I liked that comment re welding up the holes, they do get enlongated.
> I,m not a welder so is that the sort of thing a local machinery shop would
> be able to do?. I,ve got visions of a local shop dragging out his mega-amp
> welder and vapourising the thing!


I welded mine without any problems with my 360V 3-phase 400Amp Mig.
The pieces didn't vapourize, LOL

It's simple. Weld a spot into the hole on th elever from voth sides and
drill it open again. And weld a spot or two on the rod where it's worn,
and grind it back to shape.

Jan

On Sat, 16 Feb 2008 05:35:28 +0100, Jan Andersson
> wrote:

> John wrote:
>> When replacing the pump diaphragm I always tighten the 4 securing
>> screws on the pump cover with the spring allowed to extend the
>> diaphragm as much as possible. If you tension the screws with the
>> spring compressed( ie if you are holding down the pump) it can
>> limit the travel of the diaphragm.ie the diaphragm extends as much as
>> it can before being limited by the mechanism.
>
> Never thought of that, good point!
>
>
>> Jan, I liked that comment re welding up the holes, they do get
>> enlongated. I,m not a welder so is that the sort of thing a local
>> machinery shop would be able to do?. I,ve got visions of a local shop
>> dragging out his mega-amp
>> welder and vapourising the thing!
>
>
> I welded mine without any problems with my 360V 3-phase 400Amp Mig.
> The pieces didn't vapourize, LOL
>
> It's simple. Weld a spot into the hole on th elever from voth sides and
> drill it open again. And weld a spot or two on the rod where it's worn,
> and grind it back to shape.
>
> Jan
>

The tyke has been at your keyboard again Jan.
Either that or the Rum is kicking in. :-I

J.



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P.J.Berg wrote:
> On Sat, 16 Feb 2008 05:35:28 +0100, Jan Andersson
> > wrote:
>
>> John wrote:
>>> When replacing the pump diaphragm I always tighten the 4 securing
>>> screws on the pump cover with the spring allowed to extend the
>>> diaphragm as much as possible. If you tension the screws with the
>>> spring compressed( ie if you are holding down the pump) it can
>>> limit the travel of the diaphragm.ie the diaphragm extends as much as
>>> it can before being limited by the mechanism.
>>
>> Never thought of that, good point!
>>
>>
>>> Jan, I liked that comment re welding up the holes, they do get
>>> enlongated. I,m not a welder so is that the sort of thing a local
>>> machinery shop would be able to do?. I,ve got visions of a local
>>> shop dragging out his mega-amp
>>> welder and vapourising the thing!
>>
>>
>> I welded mine without any problems with my 360V 3-phase 400Amp Mig.
>> The pieces didn't vapourize, LOL
>>
>> It's simple. Weld a spot into the hole on th elever from voth sides
>> and drill it open again. And weld a spot or two on the rod where it's
>> worn, and grind it back to shape.
>>
>> Jan
>>
>
> The tyke has been at your keyboard again Jan.
> Either that or the Rum is kicking in. :-I
>
> J.


Bread crumbs and crap jammin the keys