When engine starting is difficult, or pick up begins to lag, the problem could be your vintage Japanese restoration bike’s spark plugs. Carbon buildup can be cleaned, but after time the performance demands of your vintage Kawasaki’s engine will cause spark plug electrodes to wear down. Replacing spark plugs is an easy and affordable way to restore vintage Japanese motorcycle performance. Z1 stocks race-proven NGK spark plugs. We sell vintage Kawasaki GPZ750 and KZ400 NGK spark plugs, Honda CBX and CB750 NGK spark plugs, Suzuki GS1150 and GT250 NGK spark plugs, Yamaha XJ1100 and XS1100 NGK spark plugs, and many more for the big four. We also stock NGK spark plug caps for many performance Japanese motorcycle restoration projects.