Gen 1 Spark Plugs Advice

[2007busa]

What spark plugs do you guys recommend to put in a Gen 1 and why?

[2007busa]

What spark plugs do you guys recommend to put in a Gen 1 and why?

I pulled out the NGK CR9E plugs below after 40,000kms. Bike is running stock ECU, Yoshi TRS mufflers. Plugs are in order of cylinders. Should i put in iridiums?

[Rudi Le Roux]

NGK CR9EK more smooth running and rapid throttle response.

[Camel]

Go stock, NGK, Iridium for better ignition characteristics. Shims if you're pedantic and want to line up all your electrodes.
Iridium offers benefits because its is hard. Damned hard. Therefore the manufacturer can produce a much finer tip on the centre electrode and taper the side electrode to focus the spark. If you've ever examined a normal wide tip spark plug in action you'd notice how the spark appears at random spots around the electrode and often in multiple locations at once. This inconsistency results in weaker sparks. However the difference is almost impossible to notice on the street. 0.8mm clearance and no anti-seize.
Camel

[GRUNTMAX]

Use these in your Supercharged Gen1 or Gen2;

CR10EIX NGK Iridium IX Spark Plugs

[Tony Nitrous]

Stock.

Rarely check them.

Never had a drama.

163hp on the dyno,
10.33 on the strip.

Long time since I even looked at them.

That'll do me.

[Yack0u]

I agree with Rudi.
NGK-CR9EK.
Start easier, more grunt in high revs.