Originally Posted by styxnsk1n
well i have pin pointed the problem today... being that the engine cranks fine and runs without any help, does not smoke, and has oil rerouted me away from thinking it was a rod knocking or any other major engine part failure. i decided to check my spark plugs... i took out cylinder #2 plug first and the electrode and arch were totally blown out of the plug ...cylinder #1 plug still had electrode and arch, but were pretty much at the end of their lifespan. i replaced them about 9k miles ago. people have told me today that i should replace my plugs every oil change. does anybody on here agree? but i also wonder, electrodes just dont normally blow out of a plug. something caused it to happen. anybody have any ideas? ..luckily the plugs were still under warranty through oreillys and ill get a new pair tomorrow. they are NGK Iridium X .. is there anybody that uses these plugs ever run into a problem with them?
That sounds like a plug with too high a heat range was used. The EX doesn't need iridium plugs. They're much lower resistance than the stock plugs and that can cause problems. No, electrodes don't normally blow out of plugs. Ever. If they have, then they melted because the heat range was too high. Normally you can go up or down one heat range from the stock plug without doing any damage. Too low a heat range and the plug will foul. Too high and it can detonate like yours appear to have. Click the link:
If the ground electrode is gone....then maybe the plugs are too long for your application. If the threaded shank allows you to thread them in too far they can be hit by the piston and damaged.
Plugs don't need to be replaced often at all. Maybe 40 years ago, sure. These days, not so much. I did the ones in my Aprilia shortly after I got it because I didn't know what was in there already. If I'm going through the trouble to remove them, may as well replace them. My old Gixxer, which is carbureted and has a stage III jet kit installed only needed a plug change once in 60K miles. The other bikes in my garage? Never changed the plugs in them at all. When I went to GM's training center, we were told that the modern engine doesn't require a spark plug change until 150K miles. Why? Because of the technology. The engineers determined that they needed XX,000 volts per plug to prevent them from deteriorating. The figure, if I remember it right was 60,000. Today, with individual coils for each plug, they're getting that. BTW, that training I went to? Over ten years ago.
Being that motorcycles most often have a single coil for each plug, the same principle applies. If things start running poorly, then sure, change the plugs. If it runs and doesn't have issues then the plugs are probably okay. I figure a bike, not being as sophisticated computer wise as a modern car a partial tune up every 35 or 40K is probably about right. Even then, if it's not running poorly, then wait until it does............sean