Spark plugs should be checked and gapped every 4,000 miles and replaced every 8,000 miles.
Spark Plugs recommended types according to the service manual are:
The gap specs are .7 to .8 mm (0.028 to 0.031 in.)
These photos show the locations of spark plugs 1 through 4. The cylinders are numbered from left to right.
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The procedure is:
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The first step is to detach the wires from the spark plug electrodes then completely pull out the wire tubes. Those 11" Sears pliers used in the carburetor synchronization procedure came in real handy here.
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The plug wires are numbered so the correct wire can be replaced on the correct plug. The numbers are colored also. I couldn't get a good photo of the numbers for plug wires 2 and 3.
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After the plug wires are pulled out it is a good idea to blow dirt out of the holes with an air compressor before actually removing the plugs.
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Removing plug number 1 is easy. You must drop the spark plug socket into the hole then attach a 3" extension to the socket before attaching the wrench. The plugs are not tight and should be easy to unscrew with the socket wrench. Unfortunately, my plug socket would not grab the plug in its rubber boot and the plug could not be removed using that socket. Fortunately, the plug wrench that comes in the toolkit does grab that plug nicely and must be used to remove the unscrewed plug from the hole.
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Plug number 2 is very difficult to reach. Assembling this wrench using 3 extensions plus a universal joint is needed. Thread the wrench through the frame from the top as shown. Then you must use the toolkit plug wrench to remove the plug. This is not easy to do and you have to pass your hand through the frame from the side. The engine must be cool when you do this.
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Removing plug number 3 is as tough, if not tougher, than plug number 2.
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Plug number 4 is easily reached like plug number 1.
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Spark plug tips should be a medium to light tan and should not be fouled. Use a spark plug feeler gauge or gapping tool to ensure the gaps are within spec.
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Now you have the fun job of replacing the plugs and torquing them down to specs, 13 Nm, 9.4 lb-ft.
Don't forget to replace the plug wires, on the correct cylinders of course.
When lowering tank remember to switch fuel petcock back to ON first. Make sure the fuel tank hold down bolt is properly torqued to 10 Nm, 7.2 lb-ft.
This job was a pain to do. I even have the Air Induction System removed. Doing this with all those AIS pipes in the way would be much tougher. I will seriously consider removing the radiator next time. I will coordinate replacement of the coolant with spark plug changing.
Addendum:
I can now confirm that removing the radiator makes changing the spark plugs much, much easier. Note the clear, unobstructed access to the
plugs, especially with the AIS removed.
Last Updated: 11-10-2005
Copyright © 2001-05, Patrick Glenn, All Rights Reserved.
The information presented here reflects solely my personal experience with my motorcycle and is presented
for entertainment purposes only. No information presented here is to be relied upon for issues of rider safety
nor to replace the services of a qualified service technician.
Any attempts to follow or duplicate any of these procedures are done so completely at your own risk.
By reading the information on this site, you agree to assume complete responsibility for any and all actual
or consequential damages that may arise from any information presented herein.
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