Plugs are one very important part that are typically overlooked. Having the wrong plugs can cause all manner of problems from missfiring to pinging. 

For a standard, or mildly tuned motor, we recommmend NGK BP6ES. For higher output engines, the NGK BP7ES. In some highly modified motors we have run NGK BR10EIX and NGK B9EGV. 

We keep all of these in stock, please specify which plugs you need.