Slight stumble/misfire on low speed acceleration. Thoughts?

[JBN]

Hey guys, newish member here. Having a very slight issue I was looking for some help with before buying parts.

Bike is an ‘08 and aside from yosh slip ons is bone stock with 4600 miles.

Last month I noticed the secondary injectors weren’t firing on WOT causing the bike to sputter/lag so I pulled all 8 injectors and replaced all seals and screens in them, as well as the fuel pump sock, air filter and a fresh oil change. This did the trick and the bike was performing at 100% again.

Well I went for a ride today, and noticed when accelerating from a stop and very low speed turning a slight stumble/misfire. While cruising/accelerating/WOT it doesn’t miss a beat. It isn’t a horrible miss, more so annoying just cause I know it’s there.

I’m leaning towards spark plugs but wanted to get some opinions as to other possibilities. I know, I should’ve pulled the plugs and checked them while I had it apart doing the fuel injectors but it was an oversight at the time.

I did a search and couldn’t find anything as far as a gen 2 goes, so here I am lol. Any help is appreciated, thanks!

 

[Bumblebee]

When were the spark plugs changed last?

It's surprising how much they affect the bike if they need changed

 

[JBN]

When were the spark plugs changed last?

It's surprising how much they affect the bike if they need changed

I’m willing to bet they’re the factory original. It still had the factory tires on it when I bought it at the beginning of June.

 

[Bumblebee]

I’m willing to bet they’re the factory original. It still had the factory tires on it when I bought it at the beginning of June.

I'd be changing them if I were you.

 

[JBN]

I'd be changing them if I were you.

Ordered some stock plugs I’ll change them out this weekend. Thanks for the insight.