Spark plug NGK or AC DELCO

Plugs need to be AC Delco 41993 (no substitution). I've had misfires with other "equivalent" plugs that went away with the correct plugs.

If you have a bike that fouls plugs easily, particularly with condensation, the pointy electodes of an irridium plug will still spark. My XV535 would get regular plugs wet with fuel and condensation in winter and then refuse to start. Started reliably on iridium.

I personally run NGK without any issues.

these work fantastic.

You can check the forums and it'll say the same thing your asking . It comes down to personal reference ,everyone (including myself ) that I run with in our 3rd gens we run NGK . Just make sure they are dual pronged and gapped correctly and you'll be just fine .

Use NGK iridium and you will have no problems.

I went with NGK iridium's. The "book" says they should be replaced at 100k. I mostly didn't want to have to fight with them at 100k miles to get them out.

I run usually one of 2 brands. Brisk or NGK both iridium. And both are 1 step colder than stock.

I've been pulling my CR8EIX iridium plugs out to check how they are burning a lot recently. I've been seeing some light ash deposits and high speed glazing and the iridium tips of the plugs are not as hot as I would expect them to be, i.e., they are not *white*.

I used the NGK plugs once and kept getting a pretty bad hiccup under hard acceleration.