Spark Plug questions

[jwick07]

My first plug lasted for a year with no problems until the last ride. I changed the plug and it worked great for about two months, and about 10 rides and two races.
The difference between this year and last to my quad are a 13tooth front sprocket and eight inch rims, 18 inch tires and hmf slip on. I hit my rev limiter faster and more often now,

The day my plug went to chit it seemed like from half throttle on the bike would just fall over its self cough and cut out and just not have any spark, so does hitting the rev limiter cause a plug to burn up quicker.

[redlined94]

Sounds to me like you just got a bad plug in the bunch. They are made to spark fast and hot so it shouldnt be a problem. Make sure you are runnin the right plug for it. NGK is what I run. But ya it sounds like you just might have got a faulty plug. I have never had one do that I ran same set up too.

[HP1]

There are other things that might cause a fouled plug problem, but to answer your question...Yes, on a carburated engine, hitting the rev limiter more often could cause more buildup on the sparkplug.

This is because the rev limiter cuts the spark but the carb keeps delivering fuel. This wets the cylinder walls, combustion chamber and the spark plug with some fuel. Once the engine revs drop back down below the rev limit the CDI box starts firing the sparkplug again. The residual fuel laying on the plug is more likely to cause buildup on the sparkplugs electrode than the normal atomized air-fuel mixture.

Depending on your jetting and the heat range of the plug you are running the plug should get burnt fairly clean by normal running. But if you hit the rev limit enough it could eventually foul out. How it was running bad before you changed the plug is pretty typical for a fouled plug.

I guess the lesson here would be to try to stay off the rev limiter... or you may have to change your plug more often.

Hope that helps.

[jwick07]

I was thinking of getting a aftermarket rev limiter to raise it up to help keep me off the rev limiter

good or bad idea and if a good idea what is a good brand

I was thinking ESR or Big Gun

[cals400ex]

i would stick with the dyna. the other ones that i have seen actually lose power on a dyno when compared to the stock box. the vortex didn't lose power, but it didn't gain any either.

[450R_lover]

Are you using the stock plugs? If not that is probably the problem because stock plugs are iradium plugs. Just a thought.

[chad502ex]

the biggest difference from the first year to the second few months was your hmf pipe install. I'd bet the jetting is off a bit with the new pipe causing the plug to load up over time

just my 0.02.