spark plugs

Hello everyone, I just purchased a project Yamaha XS400 a couple of weeks ago and am going to turn it into a cafe racer. While going through it to get it started, I needed to replace the plug caps and figured I would replace the plugs while I was around that area. I ordered the NGK plugs off of...

Is this normal? Bike was running beautifully several weekends out, then one day began misfiring on the right side. Right side plug looked fouled, I though a fresh spark plug would solve the problem but didn't. I noticed when the plugs were out that both cylinders have spark however when I turn...

Has anyone found a good replacement spark plug? I'm having a hard time finding them. Posted via Mobile

So my bike, 83 maxim, didn't start the other day. I had a few problems starting previous and now it just quit. Might need to charge the battery, but I noticed a curious thing while checking her over: both of my spark plugs are cracked in half. Don't know how or where the other halves may have...