Originally posted by GoFastCat@Dec 1 2004, 08:52 AM
Ok then, even to just open the gap on the plug to the high end of the specs would provide gains. I gaped mine to .033" (spec .032) from a .028 and did notice minor improvements, so that would be an improvement while still keeping the life of the coils good.
Yes, that would be a known safe gap...
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I'm not sure if you took note of when that post was started but it was in mid March 2003. No post of bad results but thats not to say they didn't happen and the person never thought of the exceeded plug gap causing it, or maybe they aren't running the plug gaps that large anymore, who knows? I would think running slightly over spec (say .035") the premature aging of the stock coil would be very little and could probably go many thousands of miles and hours without a glitch
We cannot know if going beyond the recommended gap range will have a bad effect on the coil within a short time, or a long time, or make no difference at all.
We cannot know, because there are so many manufacturing variables between brands & models... Like design, wire quality & guage in the secondary, internal coil heat dissipation qualities, etc.
There are so many possible variables that one ATV might have coils that can take a gap out of spec forever without blowing up. And some might begin to generate weak sparks within the first few years or less.
When a coil dies, it doesn't necessarily fry all at once, although it may.
A secondary coil may die a slow death, where the spark voltage may gradually decline over a long period of time. Over that time period you may lose performance gains you had at the start. So it would pay to check spark quality once in a while to see if it is getting weaker.
So I doubt you would get failure reports this early, and I don't know if people will make the connection between a weak coil and a wider than spec plug gap they did last year.
It is a gamble. It is a gamble because we cannot know. Only thing we know for sure without doubts is using the recommended plug gap is not a gamble and will yeild normal coil lifespan.
If the performance gain is worth carrying a spare secondary coil is worth it to you or anyone, by all means do it. But if you go into the woods by yourself, carrying a spare coil may make it less of a gamble. They're small, light, and not too expensive, so why not?
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There are a few aftermarket CDI's for the 400's that are suppose to provide a better spark, along with more aggresive timing curves and high rev limiter. After I do some basic performance mods I may look into getting on of them.[/b]
Yes, strong spark makes a difference. Especially the long duration type. If stock coils are used, they may also change the length of a 'normal lifespan' for a coil. Possibly some aftermarket iginitions have their own coils to sell you as well, or part of a complete system.
Their systems may be engineered to tolerate more energy and/or larger gaps to meet their performance claims without a lifespan hit. So you may end up with long lifespans, strong sparks, with little risk of getting stuck in the woods.
By all means, check it out. I'm not saying don't do it... I'm all for more power/performance. I just want you to know about these caveats that are invisible & unknown to many who give such advice.
Education is everything, I just want to pass on some knowledge to help.