I have heard that you don't to change plugs for 20,000 miles, is this true? And 2nd, is the gap preset? If not what is it?

 

I switched out to NGK iridium at 7k and didn't notice any difference, probably a waste of money but oh well. The gap wasn't set but really close, so couln't tell you for sure on all brands.

 

Gap is normally set close +/- depending on the mechanics "attention to detail" thinking who is working on the ride. Yes, plugs and machinery have came along way, but at least checking the plugs, coils, wires, valves, etc every couple months does not hurt if on the track. I always hesitate in waiting for these checks listed in the manual. Just me prolly...

 

I changed mine at 12,000 (suggested in manual). I ordered the ones with pre-set gaps, then checked them to be sure.

 

For new plugs, the gap needs to be set as per the bikes manual.

Plugs can last for 20,000 miles, but it depends on the plug, the bike (life is much shorter on 2-strokes) and a measure of luck. On the ER-6f, with iridium plugs as stock, the updated maintenance schedule call for a change at 12K miles. That's about the longest recommended interval I know of for a bike. Iridiums, btw, may give easier starting and smoother slow running, but their main advantage is that they last longer.

Plugs are cheap, and changing them can be a bitch, so in general If I have to do work that gives me access to the plugs, I use the opportunity to change them. I carry a spare plug or two, but you really don't want to be trying to change them at the side of a highway in the middle of the night when it's pissing down with rain. Sod's law says that that's when they'll fail.

Rob

 

i bought the bike used, it's a 05 zx6-r and it didn't have a manual so i don't know the gap recomended.

 

i don't have the manual, bought the bike used. I have put a jardine slip-on and mid pipe and k&n filter on the bike

 

You should think about getting a service manual if your doing the work yourself

 

CR9EI .028-.031 gap