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I took my 2000 ZRT 800 to the lake yesterday. I have been playing around with the jetting and clutching. I believe I have the clutching where I want it. But now have to address the jetting. I have jetted down to 330''s(according to my jetting chart I should be good down to 0 degrees @ ~1,000 ft)from stock 350''s. It was about 28 degrees F and I decided to check my mains by doing the full throttle run and hitting the kill switch. Now for my question. Which part of the plug should I be looking at?. My 2000 Performance manual says to read the center electrode and look for a silver spot on the tip that protrudes down at an angle. The farther down the silver color goes indicates how rich/lean you are. My plugs center electrode only had the silver at the very tip. According to the manual this would indicate a rich condition. But the plugs ceramic insulators were mostly white with a hint of tan color, I always thought this ment lean. Anyone know where I am at?.

Rob H
 

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At 28 degrees you were probably a little rich with 330s, but not too bad.  I run 320s when between 20 and 30 degrees out.  That is a little on the lean side, but I like to run as lean as possible...

As for reading the EYA plugs, I noticed the same thing as you(hard to get accurate readings).  So when I am testing, I put in an old set of ES plugs and check piston wash to get a more accurate reading on where I am at.  330s are plenty safe for running WOT for hours without worrying about a lean burn at that temp. and are safe down to 0 or better from my experiences.
Hope this helped...
 

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It is best to check the plugs immediately after a wot run.  

IE: Find a lake that you can get up to wot.  Once you are at your peek RPM hit the kill switch and roll to a stop.  

This is a little hard on the reeds, but is the best way to get the most accurate reading of your plugs.  This will show you how your plugs are burning the fuel at that RPM.  Letting the engine idle down first does little in giving you an idea of how you plugs are burning.

You want too look at the center electrode, this is where the firing of the combustion takes place.  Nice light brown color is ideal, black color is engine safe (and losing HP), white is dangerous, and will screw your engine.

From what you mentioned you are running a little on the rich side, however at 28f degrees (-2c) I would expect the it to be rich with 330 mains.  Like Mr Phazerhater said, jetting down to 320 would produce a more ideal burn at that warm of a climate.  But 330's won't hurt.

newf
 

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Discussion Starter #4
Thank you guys. I thought so. I will stick to the 330's, as I don't care to run on the edge.  The sled pulls great with the clutching I have done, so I can't complain. I can finally take my buds 2001 XC 600, (it's clutched, jetted, piped, and he just put in a cold air intake) which is a hole shot monster, from a standstill.  I really like this sled, and am planning some mods for it this summer.
 

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As phazerhater said EYA's are impossible to read. Use ES's to do plug readings(or EV's) and look at piston wash.
 
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