No, he means not aligning the threads straight; screwing the plug in crooked, thus damaging the threads on the head. If you still have the sparkplug tool that came with the bike, use it. I found it better than a regular sparkplug socket. Plus it has the built-in swivel which you'll see comes in handy (as stated earlier). +1 on the anti-seize compound.

 

WOW. maybe you should take it to the stealership.

 

or maybe i should learn english

 

the letter on spark plugs is usually the temp depending on the brand. the number is the size/form of the plug. a different letter indicates a different operating range... usually if a dealer puts a hotter or colder spark plug in it's because they're trying to band-aid fix somethings wrong with your bike (or car). also, get the recommended spark plug. If it asks for the laser-cut iridium then just get it. the fact that it's laser-cut might seem excessive especially when comparing prices but you have to realize that we're not talking about a single cylinder lawn-mower engine here. Bikes are high-revving and need precision to operate at their intended level of performance. This is why the OEM engineers chose this spark plug instead of a cheaper one that would make them more money. You might not notice a difference in performance but the improperly burned fuel depositing and creating corrosive compounds in your exhaust and on your clothing says otherwise.