Spark plug

[DGA]

what is a good spark plug I can buy at Wal-Mart for the 2001 400EX? Its my dads quad and I dont know the number of the plug.

[DGA]

i heard someone say your can use a dpr9 plug. I got a dpr9z plug from my xr250 i sold. Its never been used. Its an ngk can i use this? Sorry for the newb questions.

[underpowered]

the dpr9z is a great plug to run. that is what i use. it is slightly colder than stock which is better if you are gonna ride it hard. a dpr8z will also work.

[DGA]

thanks for the reply. what gap should i use?

[underpowered]

if it is brand new it the gap should be good, but the recomended is 24-28 thousanth of an inch.