Only running on 2 pots

[Plasticman]

The other problem with the G  reg petrol van is running....

Starts great (with jump switch to solenoid) but only runs on two pots, the front pairs exhausts are cold,pieberg carb fitted, it ran ok 12months ago when I bought it,been doing work on it prior to sale (tank out and refillled with fresh petrol) clues as prefere playing with diesel.....
mm

[Robsey]

The petrol carb engine should be quite simple.

The carb won't descriminate between one pot or another. Fuel is just sucked into whichever inlet valve is open.
So fuel is getting through okay, if two pots are working fine. It would be all or none of the pots getting fuel.

This leaves ignition as the likely issue.

The coil must be fine, as two pots are firing.
Again it would be all or none.

Plugs, leads, rotor and distributor cap.
If it has been stood, it is worth looking to see if any need a good clean.

Pop the cap off and check that the pins inside the cap are clean and dry,
Same with the curved end of the rotor arm.

Any moisture, corrosion or dirt will make it hard for the spark to be created.

Next unscrew each plug and check that the electrodes are clean and dry.
I presume you have feeler gauges, so check the electrode gap.
On a DG, the plug gap is approx. 0.7mm.

Last check is to fit the plugs into their respective leads.
Then, one at a time, hold each plug with a pair of insulated pliers and hold the electrode tip against a suitable metal earth (engine block).
Try cranking to see if a spark jumps berween the plug electrodes.

If everything is clean, dry, and securely fitted, then you should get a spark.
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If you wish to check the ignition leads...
If you have an ohmeter, then the centre lead should have a resistance around 2000 ohms (2k ohms) between the two end terminals (coil and cap ends).

And the four leads to the plugs should have a resistance around the 6000 ohms mark. (6k ohms)
Between the plug and cap ends.

If any lead varies much from those values, then they need changing.
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I am making an assumption that the valves are freely moving in the heads. Not sticking.

[Plasticman]

Thanks for that. Perfect methodical sense . Will check it through tomorrow.
Go have a look under electrical for my starter issues
And good speaking with you the other day
mm

[Robsey]

It was good speaking to you too.
Hopefully you got my email, and that the photos were of some use to you.

As for your starter issue post...
Possibly a burnt contact in the ignition switch.