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Main Area => General GS500 Discussion => Topic started by: pbureau69 on May 06, 2008, 07:20:10 AM

Title: About NGk plugs.. and Gap
Post by: pbureau69 on May 06, 2008, 07:20:10 AM
I have been reading alot from you guys out there stating " don't mess with the gap on your plug they are pre-gapped"

well I just visited NGK web site and did the engine search for the 05-GS500F
and it gave me this information

2005-2004 SUZUKI GS500F 500 (http://www.ngksparkplugs.com/apps/motorcycles/)

Spark Plug...Part.............No. Stock No. Plug Gap 
Standard.....DPR8EA-9.....4929.............0.035 
Iridium.........DPR8EIX-9...2202.............0.035

Noticed the gap indicated?

Well as it happens, in the service manual Page 1.1; (1989-2006 Haynes)

In the specifications section, it clearly indicates for NGK DPR8EA-9 or NGK DPR7EA-9 or DPR9EA-9 standard plugs the gap should be 0.8 to 0.9mm

So.. regaping the plugs you buy new, would be probably cause #1 for engine NOT running smothly...

I'd figured I would share with all, since there seem to be a little confusion/mis-information

As for damaging a new plug, with the proper gaping tool, you don't hurt the electrode one bit, just remeber to clean your hands before doing it, as oil/grease deposits will reduce the fire output on them..

cheers and ride on!
:thumb:
Title: Re: About NGk plugs.. and Gap
Post by: gsJack on May 06, 2008, 07:31:57 AM
.8 mm = .031"

.9 mm = .035"

I check gaps but have yet to find a NGK DPR8EA9 plug that wasn't a snug .035" and I've used a lot of them.

Indicated .035" is correct.

:dunno_white:

97 Owners Manual calls for 0.8-0.9 mm (0.031-0.035 in)
Title: Re: About NGk plugs.. and Gap
Post by: ajaxgs on May 06, 2008, 07:34:54 AM
the iridium fine wire tips are very brittle, regular plugs are fine to check and gap but not the iridiums!!!!!
Title: Re: About NGk plugs.. and Gap
Post by: pbureau69 on May 06, 2008, 07:42:59 AM
Quote from: gsJack on May 06, 2008, 07:31:57 AM
.8 mm = .031"

.9 mm = .035"

Ah yes, I forgot (lack of coffee) the conversion on the numbers.

Title: Re: About NGk plugs.. and Gap
Post by: gsJack on May 06, 2008, 08:00:06 AM
I wish the whole world would convert to the US inch system, I'm getting too old to strart thinking in Metric.   :laugh:
Title: Re: About NGk plugs.. and Gap
Post by: ohgood on May 06, 2008, 08:36:55 AM
Quote from: gsJack on May 06, 2008, 08:00:06 AM
I wish the whole world would convert to the US inch system, I'm getting too old to strart thinking in Metric.   :laugh:

lol

ditto. all i can think of is chocolate candies when i see specs in M&M's.
Title: Re: About NGk plugs.. and Gap
Post by: seamax on May 06, 2008, 09:06:59 AM
Quote from: ohgood on May 06, 2008, 08:36:55 AM
Quote from: gsJack on May 06, 2008, 08:00:06 AM
I wish the whole world would convert to the US inch system, I'm getting too old to strart thinking in Metric.   :laugh:

lol

ditto. all i can think of is chocolate candies when i see specs in M&M's.

It might be easier the other way round. I think including the US there are only three countries in the world that still  uses the Imperial Unit system. Everyone else is on Metric.

Title: Re: About NGk plugs.. and Gap
Post by: ajaxgs on May 06, 2008, 09:57:43 AM
Quote from: gsJack on May 06, 2008, 08:00:06 AM
I wish the whole world would convert to the US inch system, I'm getting too old to strart thinking in Metric.   :laugh:


jack i can simpathise.........when i went to school i was in the class where they taught both  .......try that one! :laugh: