Spark Plugs - NGK D9EA D8EA - 1986 GS550ES

[criticman]

I ordered several tune up items and I mistakenly ordered 1 plug instead of 4 (no clue why, I am at work so maybe my mind was on other things).

In any event, the single plug ordered was an NGK D8EA. I was going to just go ahead and order three more @ the best price I could find. The problem is I am finding conflicting recommendations for my bike.

50% of the sites/sources say D8EA while the other 50% say to go with the D9EA. I realize that both plugs will physically work and the 8/9 are heat ranges (8 being hotter).

My question is, should I just order three more of the D8EA or does the bike need the D9EA colder plug to run properly? If it helps, previous owner always said the bike ran "cold" for a long while before warming up, no matter what outside temps were for the day. Excuse my ignorance, but would the "hotter" plug help with this?

Anyway, please just give me some (tech supported) guidance on my purchase. The single plug is from Dennis Kirk, so I COULD send it back but as cheap as it was, shipping it back would cost more. So I am willing to do whatever is best here.

[bwringer]

Pep Boys and Advance Auto (Advance is also known as Checker, Kragen, Murray's, and Schuck's depending on where you are) stock NGK plugs, so you shouldn't need to order them unless you're really out in the sticks.

Autozone does NOT carry NGK, and don't let them sell you some crappy Bosch replacement. Bleauggh.

Anyway, NGK's web site sez D9EA. And if you check the Suzuki microfiche, it also calls for D9EA, so I'd say that settles the issue once and for all.

http://www.ngksparkplugs.com/part_finder/motorcycles/step4.asp?id=2373&type=reg

http://flatoutmotorcycles.com/fiche_select.asp?mfg=Suzuki&vcc=Motorcycles&year=1986&fveh=2109

However, if you go into an auto parts store, they'll just stare blankly if you ask for a set of D9EA plugs. Ask for them by the "Stock Number", which is 2420. I have no idea why NGK uses two systems of reference.

You should also be able to find these plugs at any dealer for Japanese motorcycles, ATVs, or farm equipment.

The heat range of the plug makes no difference to how hot the engine runs or carburetion. It's simply an expression of how long the insulating nose is, which helps control the temperature of this area so it operates at the correct temperature to control deposits.

[criticman]

Thanks. I had seen that the NGK site and the Suzuki mf stated D9EA, so I was leaning toward that part if no one had replied. Thanks for the explanation on the temp expression.

And although Rome, GA is crappy, it isn't too far out in the sticks so I will just pick them up at Advance Auto Parts.

[bwringer]

Looks like you're in luck -- Advance normally stocks these for a measly buck eighty eight:

http://www.partsamerica.com/ProductDetail.aspx?mfrcode=NGK&mfrpartnumber=2420

You'd pay about three bucks each at most cycle shops.

Sometimes the parts monkeys get all confused if you tell them the plugs are for a motorcycle. Several places have flatly told me they don't sell motorcycle plugs. Be persistent and gentle, keep repeating the stock number, and they'll eventually turn around and fetch your plugs from the shelf right behind the counter.

[criticman]

Luckily I have two friends that work at the one here, one owns a bike and is fairly familiar with how much in terms of motorcycle parts they actually have. I'll find time to stop by this week as I wait for my ordered parts to come in.

[criticman]

LOL. For fun I clicked on their "See all vehicles this product fits" link. One listing comes up: Lamborghini Diablo (1992-1996). Not bad company to be in when it comes to sharing spark plugs ;-)

[bwringer]

Yeah, everything is so dang expensive at the Lambo dealer. It's good to know I can drop in at Advance for tuneup parts. Sometimes they don't have 12 plugs in stock, though, and I have to send the butler out to another store.

[MelodicMetalGod]

I had the same question last year and rec'd the same answers that have been posted here.

http://www.thegsresources.com/_forum/showthread.php?t=93934

BTW, your signature indicates model year 1986, but your website indicates model year 1985. Which is correct? I've got an 85 so I'm looking for owners or the same/similar models to network with as I restore mine. Feel free to send me a PM if that's more convenient. Thanks!

[criticman]

I had the same question last year and rec'd the same answers that have been posted here.

http://www.thegsresources.com/_forum/showthread.php?t=93934

BTW, your signature indicates model year 1986, but your website indicates model year 1985. Which is correct? I've got an 85 so I'm looking for owners or the same/similar models to network with as I restore mine. Feel free to send me a PM if that's more convenient. Thanks!

Signature is correct, 1986. There was some confusion when I bought it, but getting insurance and the title cleared that up (VIN pointed to '86). Updated the website to reflect that.

[earlfor]

Just for background info, the 8 valve engines usually use a B8ES or a D8EA and the 16 valve a D9EA.

E.