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Discussion Starter #1 (Edited)
It's all about spark plugs? FINALLY TOOK IT OFF

So I have read this info on spark plugs...
http://www.ngksparkplugs.com/techinfo/spark_plugs/overviewp5.asp?nav=31000&country=US

the way they talk about it seems really important... I never thought that it can affect performance...

Now the reason of this thread is because there are stuff that I dont understand and hope that someone can enlighten me!!

1. when we install a full exhaust system with proper ecu, we have rich air/fuel mixture, thus when changing to a full system we gotta put cold spark plugs ?

2. what exactly does pre-ignition means, ignition of the air/fuel mixture before the pre-set ignition timing mark , i dont get it ?

3. A spark plug is said to have misfired when enough voltage has not been delivered to light off all fuel present in the combustion chamber at the proper moment of the power stroke (a few degrees before top dead center) , so, as an exemple, misfire means that when u crank the throttle, u get a failed response/rev, kinda?
 

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It's unlikely you'll need a colder set of plugs with the minor modifications most people do to their bikes. Generally (with cars), the rule of thumb is to go one step colder for each additional 50 hp...but each case will vary and there are more 'scientific' ways to tell for sure.

Pre-ignition = knock = detonation. Kinda sounds like marbles in your engine...do a search for detonation on google....easy to explain but easier to read for yourself. Knock is VERY bad. Avoid it all costs! On a motorcycle (which typically don't have knock sensors), you're forced to tune by ear or rely on the manufacturers settings. So in other words, listen very carefully when you decide to tweak your FI. In fact, damaging detonation begins to occur before it's even audible.
 

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I agree. There's very little chance you are changing things enough to require a different plug.

Pre-ignition occurs when the fuel/air mixture ignites before the plug fires. This can be due to heat of compression in a too-hot engine, hot spots in carbon build up in the cylinders, too heavy a load for the RPM. Those are the common causes.

A cylinder can misfire if the mixture is too lean or too rich, even if the plug fires. Plugs also can misfire if they are momentarily shorted by debris, usually carbon flakes. Plug can become "carbon tracked" where they are partially or totally shorted across the porcelain. Often this tracking is invisible. The plug cannot be cleaned. This usually happens to older plugs.
 

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Pre-ignition also occurs from running lower octane fuel in an engine designed for higher octane. Lower octane fuel in a high compression engine can ignite from simply the pressure itself before the spark. not good for the engine at all. Nice that our SV's don't require higher octane :)
 

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toward the end of my SVs life when it started using oil due to worn valve guides, I ran a hotter plug
 

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Discussion Starter #6
thx for the info!!

well on the manual they say to change the spark plug every 12000km, and im in that range, but how to you know your due to change, what kind of symptoms? I think i got 2 ;

first; first time I turn on the bike, it turns on but turns off after 2sec, and then the second time is always good....

second; when im at neutral, or when I keep the cluth, and rev it, i get a failed response, its hard to explain, its like, you feel it was gonna rev up, but it doesnt, i think thats a misfire or somthing?**this doesnt happens not often, but still does, happened to me like around 3 times i think**


are these spark plugs related?
 

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second; when im at neutral, or when I keep the cluth, and rev it, i get a failed response, its hard to explain, its like, you feel it was gonna rev up, but it doesnt, i think thats a misfire or somthing?**this doesnt happens not often, but still does, happened to me like around 3 times i think**
What you're describing sounds like a miss - aka mis-fire. I'd pull the plugs and see what they look like. If the bike sits all winter and or you were messing around with things, changing out the plugs is a good idea. Since you are right around the recommended interval, I'd do them. They are pretty easy.
 

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Discussion Starter #8 (Edited)
ok ill actually do them rite away, what should i be looking at? bah, ill take some pics of it and post them here... do I have to put gloves to touch them because of our "grease" on our hands? also, there is only 2spark plug on our sv right? one on the rear and one in front?

edit** i really need a spark plug socket wrench?
 

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Don't wait for symptoms. Change at the recommended mileage. If your hands are normally clean that's good enough. Old plugs are not reliable diagnostic tools.
 

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Discussion Starter #11

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Dude!! that is not where your spark plug goes. Your plugs are underneath the boots going into the head. Not trying to be mean but if you don't know how to find the spark plug by noticing the boot 2 inches from where you are here, maybe should have someone help you at first before wrenching on your bike. Just trying to look at for ya.
 

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Discussion Starter #16
LOL, wow, well the manual isnt really clear... so, what I unscrewed has nothing to do with the spark plug?!!!

oh well, thats what happens when a n[][]b try to find the spark plugs !! I screwed back everything, im gonna check out the thing you pointed!! loll

thx, ill be back with updates

**i dont have the tool kit
 

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Make sure when you unplug the boot, that you actually grab the boot... don't just pull on the cable. Use a spark plug socket with the rubber cushion in it, that way you don't tweak the plug sideways and snap it in half. Use your fingers to start the plug, then add the socket and extension.. finish getting it finger tight, then add the ratchet to get it tightened. You don't need to torque the crap out of it either.. just make sure it's tight. Go to the other plug and repeat. And don't leave you plugs out for a long time, either put it back in or replace it. If you leave the plugs out, something else may find it's way in. If you get debris in the cylinder, that will just start grinding away as the piston moves. It's an easy job to change plugs, just take your time and don't cross thread them.
 

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Discussion Starter #18
Make sure when you unplug the boot, that you actually grab the boot... don't just pull on the cable. Use a spark plug socket with the rubber cushion in it, that way you don't tweak the plug sideways and snap it in half. Use your fingers to start the plug, then add the socket and extension.. finish getting it finger tight, then add the ratchet to get it tightened. You don't need to torque the crap out of it either.. just make sure it's tight. Go to the other plug and repeat. And don't leave you plugs out for a long time, either put it back in or replace it. If you leave the plugs out, something else may find it's way in. If you get debris in the cylinder, that will just start grinding away as the piston moves. It's an easy job to change plugs, just take your time and don't cross thread them.

ok, well i went again and tried to unplug the "boot"(is the boot the rubber thing?)... Dindt wanna pull hard, i dont know what I should pull exactly( is it the rubber that i have to take off?), and what I should be seeing, is there a normal nut under the rubber?
 

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No offense, but it really sounds like you should be taking this to a mechanic.

Haven't you ever changed the plugs on an internal combustion engine? Car, lawnmower, weed whacker, anything?

I hope you at least have a shop/service manual to guide you...

Aside from your lack of a proper plug wrench, do you have a set of feeler gauges to check the spark gap on your new plugs? Do you have antiseize compound (for the threads of the new plug) and dielectric paste (for the rubber boot and plug insulator)?
 

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give him a break, he needs to learn sometime right?

I can't tell you how many times I took apart the wrong thing before I found what I was looking for.

And in your first question you talked about running the bike rich. If you screwed with your fuel map that could be a prime reason for your bike missing. and fouled plugs.
 
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