Plug gap recommendations

[Loctite77]

So I am getting ready to replace the entire ignition system on my 76 750F This is what I have.
pamco electronic ignition
ultimate high output coils
NGK DR8EIX Iridium plugs
NGK Resistor plug caps.

I run KandN pod filters and the carbs are jetted a little larger at 115 with the clips in the lowest notch and an open pipe.

I've done a lot of searching and reading and have seen recommendations from stock (.24-.28) up to about .32 so I'm wondering what you guys think? I'm leaning towards the larger gap but if I do what would the symptoms be if it's too large? I don't do a lot of spirited riding, just around town and open it up good on occasion.

Thanks!


Yeah Son!

 

[VonYinzer]

Start at stock. See how it runs. Play with settings from there.

 

[teazer]

With resistor (Iridium) plugs you need caps without resistors.

Wider gaps need more voltage to fire and if the ignition can handle it it will start the fire better (more regularly) even with a less than perfect mixture, but if teh ignition struggles to build enough voltage to jump the large gap it will misfire. See what the plugs are gapped at and start with them all the same with stock (for the plugs) gaps.

 

[Loctite77]

With resistor (Iridium) plugs you need caps without resistors.

Wider gaps need more voltage to fire and if the ignition can handle it it will start the fire better (more regularly) even with a less than perfect mixture, but if teh ignition struggles to build enough voltage to jump the large gap it will misfire. See what the plugs are gapped at and start with them all the same with stock (for the plugs) gaps.

That makes sense but I read this on the cycle change.net page on electronic ignitions. Basically they are recommending resistor caps AND plugs.

Q: Why should I use a resistor spark plugs & spark plug wires?

A: "R" or resistor spark plugs use a 5k ohm ceramic resistor in the spark plug to suppress ignition noise generated during sparking.

You must use resistor spark plugs & wires in any vehicle that uses electronic ignitions or on-board computer systems to monitor or control engine performance. This is because resistor spark plugs & wires reduce (EMI) electromagnetic interference with on-board electronics.

They are also recommended on any vehicle that has other on-board electronic systems such as engine-management computers, two-way radios, GPS systems, or whenever recommended by the manufacturer.

In fact, using a non-resistor plug or low resistance spiral wound spark plug wire in most applications may actually cause the engine to suffer undesirable side effects such as an erratic idle, high-rpm misfire, engine run-on, power drop off at certain rpm levels, abnormal combustion and probable damage to the ignition and/or ignition coil.


Yeah Son!

 

[teazer]

Do you have a lot of on board advanced electronics that will be upset by the RF noise?

More to the point. If you already bought those plug caps, go ahead and use them and at some point in teh future, get some zero resistance caps and try them.

 

[Loctite77]

No I dont... I was more interested in the last paragraph regarding undesirable engine performance. I do already have them and will give them a go and see how it goes.

 

[teazer]

We run zero resistance plugs and caps in our CDI ignition race bikes with zero issues at high or low RPM. That last paragraph seems to be a catch all of things that might happen if something else is wrong or maybe they are suggesting that with advanced electronics and no suppression that might happen.