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Discussion Starter #21
You say 9 but there are two types of 9s boss. I run a non-projected tip because of this exact scenario and my aggressive timing curves. Projected tips will
Act is flame throwers and duplicate this scenario more times than not. CR9E is my current plug in a stock bore setup and many degrees advanced timing. I do watch the plug often and replace it frequently in heavy weather swings here in TX and time my bike accordingly. Colder drier air gets a few degrees retard to keep the piston happy.
Thats the low reach spark plug yes? Dont you have issues then with exposed threads of the head?
 

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No he's talking about the other iridium plug. The one that's actually the right length. I use that plug with advanced timing without issue.

Edit: CR9EIX
 

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CR9EIX and CR9E are the same plugs. One is iridium, one is copper. Both are non projected tip. CPR9E and EIX would be the projected tip and let's face it...these are air cooled engines. Extracting heat from the chamber is what makes power. That's the plugs biggest job outside of providing spark which is a given. I don't use iridium plugs at all. They're not good indicators of what's going on inside the chamber because iridium will show signs that will send you chasing your tail when reading them. I always use cooper plugs for that reason. And if it's a NA application I may stick one in for long term use. Copper
Plugs are $2 and yield the best results for my tuning ability.
 

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If you look at the plug from the side, you can see lots more porcelain/inner electrode length on the projected tip plug. The inner/outer electrode protrudes further out into the combustion chamber.
 

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Is this true spark knock? The plug will show signs of detonation/pre-ignition for sure if thats the case. Has any octane booster been dumped in the gas tank to see if it is a fuel octane issue?
 

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Discussion Starter #27
Honestly not sure. Ill pull the plug and take a look. Grom ran like a god damn champ tonight in the cold evening around town.

I was honestly seeing if it was feesable to retard the timing via the pickup... but after doing the cam chain tensioner last night.... its pretty much not possible to slide the pickup forward or back in rotation due to how the casing is done on it and the side case.
 

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The air when cold is much more dense and dryer. If the bike is richer in the summertime and timing is kept the same...you can burn a piston up. I see it all the time in the automotive world when water grains aka humidity dries up and folks forget to retard the timing a few degrees. More humid air can benefit from increased timing to burn similar mixtures.
 

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And for gods sake please put a fresh plug in the bike and make a long 4th gear pull on it before pulling it out. Idle time Will
Skew the results we are trying to look for in the top ring of the thread face.
 
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