I did a search but was unable to find the type of plug needed for a 91 GS500.
Are they all the same for all years??
Anyone know offhand want I need for a 91?
just bought two spark plugs for my 93 - NGK DPR8EA-9
Though I was loyal to NGK for many years (never had a problem with NGK plugs until the summer of 2003), some of us have switched to Champion 809 sparkplugs; do a search for the terms "champion" and "809" to see related posts...
I use copper NGKs in my car (way better then Bosch platinums IMHO, and there is no way in hell I'd put Champions in there, makes me think of lawn mowers lol) The only downside is I have to change them with every oil change. I don't mind, they're super cheap, under 2 bucks a piece if you buy them in packs of 10. Don't know if it's the same deal with the GS, just making the suggestion the NGKs may in fact perform better but require more maintenance.
Quote from: Grainbelt on April 03, 2006, 10:44:03 AM
just bought two spark plugs for my 93 - NGK DPR8EA-9
+1
i swap out to NSK DPR7EA-9 in colder weather
Quote from: LimaXray on April 03, 2006, 12:44:05 PM
I use copper NGKs in my car (way better then Bosch platinums IMHO, and there is no way in hell I'd put Champions in there, makes me think of lawn mowers lol) The only downside is I have to change them with every oil change. I don't mind, they're super cheap, under 2 bucks a piece if you buy them in packs of 10. Don't know if it's the same deal with the GS, just making the suggestion the NGKs may in fact perform better but require more maintenance.
Your GS isn't a lawnmower, it's a motorcycle, and if you'd researched about the KNOWN problems with NGK sparkplugs as I suggested, you wouldn't confuse the two. I don't give a shaZam! what type of plugs you put in your own engine, but the OP wanted to know which plugs he should buy for his '91, and I answered his question. Don't be so friggn' lazy and close-minded; use the search function and learn why the Champion plugs are preferred by some of the long-term members here. I also mentioned that I was a loyal NGK user for MANY YEARS, but that I've had PROBLEMS with NGK plugs, and the CHAMPION sparkplugs have SOLVED those problems. You're a self-admitted NOOB with your GS500, but you've posted a remark about "LAWNMOWER" sparkplugs without even bothering to find out WHY someone else recommened a different type of plug than the brand you use in your CAR, which makes no sense.
FWIW, I also use copper NGKs in both my cars and my truck; they are NOT the plug of choice for the GS500 engine, regardless of year or model. Screw your BIAS against Champions; use what works...
The Suzuki service manual quotes for the GS500EM (91-Model) NGK DPR8EA-9 or Nippon Denso X24EPR-U9.
I wasn't talking about the GS. I did several searches and there is a lot of bashing of the NGKs. I felt the need to stand up for them, not for use in the GS, but for the brand in general. Maybe they don't work for the GS, but I like them, I think they're a great plug. I tried to make it clear I wasn't talking about the GS, just making a side note. I don't like champions, I only use them in single cylinder engines (aka a lawnmower). I haven't had good luck with them from my experience, but as I stated my experience isn't with the GS. Never the less I will try champions on my bike because they are so recommended, and I would never ignore a more experienced persons advice just because of my brand preferance. I should have made this more clear.
If the plug is fouling go up the heat range. If you get preignition or burned insulators go down the heat range. Simple as that.
The Champion plug probably runs hotter than the NGK, thus the lack of fouling problems. Heat ranges are not comparable between brands.
A significant number of "brand failure" claims are due to the customer misunderstanding how to apply the product. Spark plugs, oil, gasoline, pickup trucks, and lawnmowers are all examples.
Whatever works... :)