what spark plugs do you guys recommend.  i want realy good ones, dont care how expensive,  i have bosch +4's in my car and love them

regular ngk only nothing else

I thought the same thing for a while, and ended up getting NGK Iridiums thinking that $$$=better. My bike never ran well with them, and as soon as I replaced the Iridiums with new NGK standard plugs it ran much better.

Check out this post for part #s

Some people have problems with the stock NGKs being too cold and causing fouling after a rejet and use Champion 809's with great success.  I haven't had any problems with the stockers, but if I do I will try both the Champions and a heat range or 2 hotter in the NGKs. 

NGK's are the best plugs IMO, followed closely by Bosch.  I switched from Bosch platinum's to copper NGKs in my car and will never go back.  Not only do they perform better, they are also dirt dirt cheap.  More $$$ does not mean better.  I think the multi electrode plugs are just silly because the arc will always jump to the one closest electrode and never to the rest.  Maybe there's some benefit, I don't really know.  If your car is turbo'd I'd highly recommend not using the multielectrode Bosch plugs because I have heard a couple stories of an electrode breaking off, getting blown out the exhaust and destroying the turbine wheel.   

Everyone is gonna have an opinion on this, its brand loyalty. My honda's ran horribly with NGK's...i swore them off forever. My dad runs NGK's in his Harley, but I only use autolites with the copper core. Only thing that seems to work in my GS and Hondas.

you people can argue till your blue in the face jap vehicles are designed to run on ngk or nd ,german/swede get bosch ,general motors get ac delco,fords get motorcraft,and never screw a champion plug in anything but a chrysler product-harley or lawnmower,if the heat range is wrong for a rejet go up or down but stick w/ the plug that your product was designed for.

Is it because of the threads?

Quote from: scratch on May 10, 2006, 02:17:51 PM
Is it because of the threads?

And the way they are connected to the coils.

I tried some plugs from AutoZone (AC Delco, I think? I forget) and the spark plug cap wouldn't go over the plug. Then the guys at AutoZone made ME fish through the trash to get my plugs back. I'm not going there ever again.

Sometimes there is a sleeve threaded onto the top of the sparkplug; was that there?

Quote from: scratch on May 10, 2006, 02:32:25 PM
Sometimes there is a sleeve threaded onto the top of the sparkplug; was that there?

Wasn't threaded, but form fitted on there. Couldn't get it off. It was more like a sleeve plus a silver ball on top, the plug cap wouldn't even go over the little silver ball.

Just some general info I thought was pertinent...

"A spark plug does not make your engine run hotter or colder. The terms hot or cold refer to the temperature of the tip of the spark plug itself. The plug must keep a temperature of, between 752 and 1652 degrees Fahrenheit. If it gets too hot it can fire off the air/fuel mixture at the wrong time. This can cause detonation and/or pinging which will put a hole in your piston... not good. If it gets too cold it will not burn off the carbon and fuel deposits on it's tip and the plug will foul out (stop working) not good either."

http://www.dansmc.com/sparkplugs1.htm

All I've got to say is OEM plugs all the way, 6 years and running strong!!!

+1 on the stock plugs for a stock engine / stock jetting. NGK 4929. 

It's not DPR8EA-9?  (<--typed that from memory)

they're the same plugs, NGK just uses different numbering for the same plug

but yeah, unless you have a reason to use a different plug, stick with the stockers

Yeah, the NGK DPR8EA-9 is now known as (and is the same thing as) the NGK 4929:

I've been on NKG's for a season and a half now... no complaints


[threadjack] Nice set of Ezy-outs you got there Phaedrus! [/threadjack]

those aren't ezy-outs there dumbass reversal tools!!!!!!just kidding that is a nice set

I picked up the Iridium plugs from NGK.  Hope they work out.  Has anyone had any success with them?  I read that another member didn't like them.

I use NGK IRIDIUMS on my 2004 GS500F and it runs great!

The idle was so much smoother after switching from a new set of regular ngk copper.

Because the centre is so FINE the spark is always sparking at the same place every time unlike a regular ngk which can more around on the large centre.

Plus the ground electrode is tapered to reduce quenching.

I will never go back to regular ngk's!  I've had the Iridiums for 11000 kms and they don't even show a bit of wear which is surprising as I usually drive at 7000 rpm to redline frequently.