Spark Plug Question
- Thread starter B14573r
- Start date
how old is ur spark plug??? try cleaning it and then riding and pull it out and tell us what it looks like after
start by finding out what size jet you have if you do not know how to find your jet size look in the do it yourself section and and click how to clean your carbureator
well your jet is stock if i'm right so its normal but i'm not sure if it should be dark black because the color you would want is almost a cardboard color if yuor blaster runs fine then there shouldn't be a problem
B
Ben
Guest
Yes, the spark plug color will change if you start tinkering with jets. If you have a well-running, completely stock Blaster with no engine modifications at all, then don’t worry about it; trust the Yamaha factory and just ride it.
But if you plan on changing to an aftermarket filter or pipe or something that will have a dramatic effect on engine performance, you will have to rejet. With just a few basic ad-ons, you can still retain the stock pilot jet and just tweak the idle mixture settings. But you will probably have to change the main jet.
The main jet comes into effect at ¾ to full throttle so that’s where you have to test it (although it does sometimes have surprising effects at lower speeds). To test the main jet, put in a brand new spark plug and ride for a few miles at ¾ to full throttle. Then quickly pull in the clutch and kill the engine. If you let it idle before stopping the engine, the test will be useless. Now, pop out the spark plug and take a look at it; it will tell you if your main jet is rich or lean. Just compare it to the pictures at this website http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html. It just depends on how rich or lean you are that determines what size jet to try next, but generally only go up or down a few sizes; no huge size changes. And it may take a few spark plugs and different jets to get things looking good. Hope that helps.
But if you plan on changing to an aftermarket filter or pipe or something that will have a dramatic effect on engine performance, you will have to rejet. With just a few basic ad-ons, you can still retain the stock pilot jet and just tweak the idle mixture settings. But you will probably have to change the main jet.
The main jet comes into effect at ¾ to full throttle so that’s where you have to test it (although it does sometimes have surprising effects at lower speeds). To test the main jet, put in a brand new spark plug and ride for a few miles at ¾ to full throttle. Then quickly pull in the clutch and kill the engine. If you let it idle before stopping the engine, the test will be useless. Now, pop out the spark plug and take a look at it; it will tell you if your main jet is rich or lean. Just compare it to the pictures at this website http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html. It just depends on how rich or lean you are that determines what size jet to try next, but generally only go up or down a few sizes; no huge size changes. And it may take a few spark plugs and different jets to get things looking good. Hope that helps.
