1968 Commando: left cylinder does not start (2016)

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DogT said:
Send it to me, I'll fix it and test it.
Click to expand...
Hi Dave,
Thank you for your kindly offer.
The shipping costs are too much expensive, not worth it.
Ciao
Pieto
 
pierodn said:
The shipping costs are too much expensive, not worth it.
Click to expand...

Is there anyone local to you that does ultrasonic carb cleaning?
 
pierodn said:
DogT said:
I would replace the old idle circuit with new parts ala Bushman. These carbies are so dead simple there's no reason they shouldn't work unless the slides are worn out. I bet they can be made to work.
Click to expand...
Hi Dave,
I agree.
But this time the left 930/27 did not want to work.
The circuit was well cleaned but it did not want to work.
Why?
I dont know.
Ciao
Piero
Click to expand...

Try soaking carb body in paint thinners, and then blow out pilot jet holes with 125 psi compressor in two places, from bellmouth and pilot jet hole With pilot jet removed, holding finger /thumb on one of the outlets. If this small hole is clear-you should be able to feel the wind getting through when blown with airline.
If anything is lodged in there they can be a devil to clear :evil:
 
Rohan said:
So Piero, does your amal have this type of idle jet ??

Bob Z. said:
Here is the pilot jet as used prior to 1969.
1968 Commando: left cylinder does not start (2016)
Click to expand...
Click to expand...

Needless to say that IF there was no "pressed in brass jet" visible when Piero drilled out the opposite side of the idle circuit, then there needs to be a jet threaded into the port like the one in the picture. Without a jet in one of these places, the carb will not work. As Dogt pointed out, maybe that's why removing the idle screw completely helps to get the cylinder closer to a mixture that will ignite... Having NO jet at all is no better than having a plugged jet.

Also, the 2 ports shown in the picture below, and their mixing chamber must be clean for the idle circuit to work. I use compressed air and a sewing needle to poke them and blow them clean. Sometimes compressed air won't clear ports that have baked on deposits.

1968 Commando: left cylinder does not start (2016)
 
Bernhard said:
pierodn said:
DogT said:
I would replace the old idle circuit with new parts ala Bushman. These carbies are so dead simple there's no reason they shouldn't work unless the slides are worn out. I bet they can be made to work.
Click to expand...
Hi Dave,
I agree.
But this time the left 930/27 did not want to work.
The circuit was well cleaned but it did not want to work.
Why?
I dont know.
Ciao
Piero
Click to expand...

Try soaking carb body in paint thinners, and then blow out pilot jet holes with 125 psi compressor in two places, from bellmouth and pilot jet hole With pilot jet removed, holding finger /thumb on one of the outlets. If this small hole is clear-you should be able to feel the wind getting through when blown with airline.
If anything is lodged in there they can be a devil to clear :evil:
Click to expand...

Hi.
The circuit is cleaned, the air and cleaner fluid enters and exits out each hole.
Ciao
Piero
 
o0norton0o said:
Rohan said:
So Piero, does your amal have this type of idle jet ??

Bob Z. said:
Here is the pilot jet as used prior to 1969.
1968 Commando: left cylinder does not start (2016)
Click to expand...
Click to expand...

Needless to say that IF there was no "pressed in brass jet" visible when Piero drilled out the opposite side of the idle circuit, then there needs to be a jet threaded into the port like the one in the picture. Without a jet in one of these places, the carb will not work. As Dogt pointed out, maybe that's why removing the idle screw completely helps to get the cylinder closer to a mixture that will ignite... Having NO jet at all is no better than having a plugged jet.

Also, the 2 ports shown in the picture below, and their mixing chamber must be clean for the idle circuit to work. I use compressed air and a sewing needle to poke them and blow them clean. Sometimes compressed air won't clear ports that have baked on deposits.

1968 Commando: left cylinder does not start (2016)
Click to expand...

Hi.
Yes.
There is no "pressed in brass jet" visible with drilled out the opposite side of the idle circuit.
You say that Without the jet in your first picture the carb will not work.
I believe it.
In fact the Amal 930/27/28 fitted on my 1967 Atlas have that jets.
And this cannot be an accident!
I dont know why there was not this jet fitted on this 930/28 carb.
But i did not have this jet.
Who supply it?
Ciao
Piero

P.s.: the 2 ports are well cleaned, all the circuit is open
 
pierodn said:
Hi.
Yes.
There is no "pressed in brass jet" visible with drilled out the opposite side of the idle circuit.
You say that Without the jet in your first picture the carb will not work.
I believe it.
In fact the Amal 930/27/28 fitted on my 1967 Atlas have that jets.
And this cannot be an accident!
I dont know why there was not this jet fitted on this 930/28 carb.
But i did not have this jet.
Who supply it?
Ciao
Piero

P.s.: the 2 ports are well cleaned, all the circuit is open
Click to expand...

If there's no pressed in jet where you drilled out for the bushman's modification then you need to thread a jet onto the underside of the carb like is shown in the picture below.

1968 Commando: left cylinder does not start (2016)


You can buy these jets here: http://amalcarb.co.uk/mk-i-concentric-series/900-series/jets/pilot-jet.html I believe the proper jet size for amal 930's are the "25cc" size. (You should check the size because I'm not sure...) good luck.
 
L.A.B. said:
pierodn said:
In fact the Amal 930/27/28 fitted on my 1967 Atlas have that jets.

I dont know why there was not this jet fitted on this 930/28 carb.
Click to expand...


Are you sure 930/28 is the carb number, as the standard 'pair' would normally be 930/26 and 930/27?

http://amalcarb.co.uk/carburettor-for-a ... 30-27.html
http://amalcarb.co.uk/carburettor-for-a ... 30-26.html
Click to expand...
Hi Les,
sure my 1967 Atlas fits the 930/26/27, sorry for my mistake.
The 68 Commando left should be 27, sorry.
Ciao
Piero
 
o0norton0o said:
pierodn said:
Hi.
Yes.
There is no "pressed in brass jet" visible with drilled out the opposite side of the idle circuit.
You say that Without the jet in your first picture the carb will not work.
I believe it.
In fact the Amal 930/27/28 fitted on my 1967 Atlas have that jets.
And this cannot be an accident!
I dont know why there was not this jet fitted on this 930/28 carb.
But i did not have this jet.
Who supply it?
Ciao
Piero

P.s.: the 2 ports are well cleaned, all the circuit is open
Click to expand...

If there's no pressed in jet where you drilled out for the bushman's modification then you need to thread a jet onto the underside of the carb like is shown in the picture below.

1968 Commando: left cylinder does not start (2016)


You can buy these jets here: http://amalcarb.co.uk/mk-i-concentric-series/900-series/jets/pilot-jet.html I believe the proper jet size for amal 930's are the "25cc" size. (You should check the size because I'm not sure...) good luck.
Click to expand...

Hi.
Thank you so much.
Ciao
Piero
 
Well, I assumed it would not be worth it to send the carb from IT to USA but I had to say it. But I'm still not clear, has this modification been done, if not, that is what I would do.

http://www.jba.bc.ca/Bushmans%20Carb%20 ... tml#3SCREW

That tiny hole can be very hard to find, too, or it may have been cleaned too much and the metering is totally wrong?

As far as I know the other jets are plug and play.
 
DogT said:
Well, I assumed it would not be worth it to send the carb from IT to USA but I had to say it. But I'm still not clear, has this modification been done, if not, that is what I would do.

http://www.jba.bc.ca/Bushmans%20Carb%20 ... tml#3SCREW

That tiny hole can be very hard to find, too, or it may have been cleaned too much and the metering is totally wrong?

As far as I know the other jets are plug and play.
Click to expand...
Hi Dave.
Drilled the other side you can see easly trought the hole from one side to the other.
With the brass into it would not be possible.
Ciao
Piero
 
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