It's just scary

how well my bike is running right now! I've been fighting the Amals and considering a Mikuni conversion due to.

1. Idle was all over the place. Wanted to die at stop lights or race.

2. Steady throttle would cause surging and exhaust banging.

So I've done the following and now the Norton drives like it's fuel injected!

1. Sleeved the carbs

2. New needle jet

3. Correct needle for 74 850 on middle notch

4. Cleaned the air jet

5. Setting the electronic ignition to 31 degrees

6. Balanced the carbs at the top adjustment screws by extending the throttle cable removing all the slack and setting the individual cylinder to the same RPM with one plug removed then lowering both slides the same amount setting the idle to 1000 RPM.

7. Setting the air screw to a nice steady tick over.

Now something else has to go wrong! :roll:

Encouraging report to read,
Your pensiveness is shared by us all. My close Commando buddy
Westley tells everyone how happy after 20 yr to finally get
his '71 gone through and a delight to just hop on and ride,
but almost hates too - for identical reasons as you state,
what's going to happen next to spoil the mood.

hobot

Bookmarking this. Good info.

Since you say this: "same RPM with one plug removed" hoping you kept that unused plug in the wire cap and attached to the head with a ground lead or the next( thing ) will be a duff coil. When a coil fires the energy will find ground, if there is no plug on a ground it normally goes right through the side of the coil body. But it will find ground.

Since you say this: "same RPM with one plug removed" hoping you kept that unused plug in the wire cap and attached to the head with a ground lead

Click to expand...

+1 on Greg's comment, particularly with an electronic ignition, despite the procedure being described in the factory service manual.

An alternative might be to unclip the lead from the plug and clip it to a spare plug which is grounded to the head, providing a path for the voltage to discharge.

A careful adjustment of the throttle cables to insure both slides are lifting simultaneously is a first step, then I like to use a TwinMax or carbstix type tool connected to the balance tube ports in the manifolds to set the idle and idle air mix. Although after 35 years I can come awfully close "by ear" even with both plugs firing.

Using this method, my MkV 750 will idle at 750-800 rpm all day and my 850 (with 2S cam) is happy at 900-950.

In any event, you have discovered what many of us have. The Amals can work on a Norton as well as the Mikuni when set up properly.