Change the sparkplug
 

Since there wasn't a concise thread on this, I decided to post a few pics of how to get access to and remove the sparkplug from the GZ. This is detailed in the manual, with pictures even, but the scan quality isn't the best and it always helps a little having more detailed pictures.

I used the OEM toolkit for the procedure. The sparkplug wrench is 4th from the left, and when paired with the screwdriver extension (3rd from left), works very well and has no problems fitting into the relatively tight space. I added some cotter pins, a sparkplug gap tool and a pair of needlenose pliers to my kit.

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The sparkplug is accessed from the left side of the bike:
http://www.postimage.org/aVBM5gi.jpg

You have to remove the cylinder head cover plate with the small allen wrench.
http://www.postimage.org/aVBMpdr.jpg

http://www.postimage.org/PqCzYhi.jpg

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Find the sparkplug wire boot and remove it by pulling up. You may have to finagle it a bit to get it to completely clear the plug top without binding up against the tank. Be careful not to crimp or break the wire or wire casing.
http://www.postimage.org/aVBNIx9.jpg

http://www.postimage.org/gxyKYkS.jpg

Use the sparkplug removal tool or a metric deep socket with a small extension to remove the plug. Remember, rotate counter-clockwise to remove it.
http://www.postimage.org/gxyLhi0.jpg

http://www.postimage.org/PqCAGaS.jpg

Clean the cylinder hole, and be careful not to drop dirt or grime onto the top of the piston. Notice the "shipping" stains on the heat dissipation fins. This is not an oil leak.
http://www.postimage.org/aVBOlrr.jpg

Reverse these steps to install a new plug. Don't forget to gap the new plug to the correct setting (0.6-0.7mm / 0.024"-0.028") before you install it. Tighten it with your fingers first, then torque it correctly (18N-m or 13 ft-lbs). This is generally only 1/8th turn of the plug past finger tight. NO MORE. You do not want to strip the plug threads nor damage your block.

Enjoy.

Re: Change the sparkplug
 

Excellent post. :2tup:

Just one comment from a REAL bad personal experience:

Clean around the base of the plug BEFORE you remove it. Compressed air is best. Loosen it and then blow again BEFORE removing the plug.

Wonder why I say this? Honda 550 Nighthawk. 4 plugs. 3 came out no problem. When removing the wrench and plug on the 4th, I see a small, round rock roll through the hole and INTO THE CYLINDER. One giant AW CRAP! :skull:

Re: Change the sparkplug
 

Very Helpful. Thanks for your help! I looked in the How section before I posted on it. Good to know that there is one now. This is a very helpful forum.

Re: Change the sparkplug
 

No problem.

Re: Change the sparkplug
 

Hi everyone I am new here and just got myself a 2005 Suzuki GZ250 just last week!
While here on the subject of sparkplugs does anyone know the sparkplug #for NGK ? thanks!

Re: Change the sparkplug
 

BR8HSA

Re: Change the sparkplug
 

Plug is a 17mm deep socket

Re: Change the sparkplug
 

Love, love, love the post and pics, Patrick! Thanks. Now, can you explaain what the "shipping stains" are and the cause? I thought mine were an oil leak.

Re: Change the sparkplug
 

Bikes (and cars) that come from Japan are often coated with a greasy or waxy substance to protect metal parts against salty seabreeze/etc. This coating is typically removed by the dealer. However I'm guessing that perhaps there are hard to get to places (on the fins perhaps?) where it is NOT removed but it eventually melts or puddles below the fins.

When I worked in an auto dealer all the Nissans (Datsuns back then) came off the truck with the wax on them. (It's name escapes me now, but I think it began with a "C")

Re: Change the sparkplug
 

Cosmolene. Mineral spirits will easily remove.

:)