I've been reading all the other "sputter" and "spitting" threads but I thought I would throw my unique situation out there.

Just changed the spark plugs on my '05 XL 1200C and my wife's '05 883L to the HD Platinum plugs from my local HD dealer. Now the 2 bikes are "sputtering" on take off...like it's flooded, or missing. Did I do something wrong when putting the plugs in?

 

First try putting the old plugs back in, If it runs better you got a bad set of plugs, if it still runs poorly check inside the plug boots for rust or corrosion.

 

Check the gap.

It has been my experience in 50 years of fooling around with engines that spark plugs are a good way to waste money. With todays gas, stock gets the job done. In the old days you had to change spark plugs all the time. Today I hardly ever.

I check them though.