A few years back Jeff and I had a back and forth discussion about the relative merits (or LACK there of) of the Nology Hot wires. Here's a chunk of what I said at the time:
The upside, the Nology wires are really nicely made and the Beru spark
plugs they sell are very high quality but on the downside :
Nology claims :
"Anyone who had physics in college knows the formula for power. In this
case we're referring to ignition spark power. Power equals work
divided by time (P=W/t). Thus, to get more power, you need to do the same
amount of work in less time." Sounds simple enough! Manufacturers of
conventional ignition systems though, want you to believe that it is possible to increase the power of ignition systems by lengthening the spark duration. This is not true! Lengthening the spark duration actually reduces spark power, as we already know P=W/t (Power=Energy/Time). "
You don't have to be Richard Fenyman to realize their website is filled with loads of this pseudo science drivel. They've really jumped on the Short duration, POWERFUL spark bandwagon. This might be useful if you were welding, but it's been proven time and again that once the required energy level to start a stable flame kernel is reached, that additional energy serves no real purpose unless that energy can be extended or repeated.
CDI ignitions by design tend to produce very short duration sparks, which at anything but HIGH RPM tends to be a DISADVANTAGE. As a rule short duration sparks tend to produce flame kernels that at low speeds or lean mixtures are easily quenched regardless of how much energy was used to start them.
Two-strokes have the added disadvantage of poor mixture distribution at low speeds, and high levels of residual exhaust gas, which makes for localized lean pockets in the chamber that are difficult for a short duration spark to
fire reliably. It's not a coincidence that CDI units which produce multiple short duration sparks of variable duration based on RPM are the most common ignition sources in every serious form of racing. I learned a lot of these lessons over 20 years ago when I was testing the original Gerex Multi-spark ignitions, on air cooled turbo charged drag race motors. The published research that has been done since then has done nothing to dissuade me from my original thoughts on the subject.
Circle Track Magazine ( May, 1996 issue) test showed Nology "HotWires"
produced no additional horsepower (the test actually showed a 10 horsepower decrease when compared to stock carbon conductor wires). Circle Track tends to be one of the few magazines that does scientifically accurate, unbiased, real world testing.
"When the spark occurs, all the thermal energy (heat) is transferred to the fuel/air mixture, where it initiates combustion. A
hotter spark will transfer more thermal energy and therefore accelerates flame front propagation. The fuel is used more efficiently and engine performance increases."
More pseudo science misinformation. My auto shop teacher in high school
used to go APE when someone said HOTTER spark around him. It took me
a few years to appreciate why he was so intolerant of this out of context
misrepresentation of basic principles, but I eventually learned. The
thermodynamics, and physics involved is pretty long and probably boring ,
so here's a few basic facts explaining ignition from the highly regarded
book "Mixture Formation in Spark-Ignited Engines" by H.P. Lenz :
"In a spark-ignited engine, ignition normally occurs when a small portion of the mixture is caused to react by the passage of a spark at a temperature between 3000 degrees C and 6000 degrees C. The effect of heat is of SECONDARY importance, the decisive factors for initiating ignition are molecular excitation and ionization. "
I agree that their Web site's "physics" are weak at best. As an EE (electrical engineer), it didn't compute for me. I also know that multiple spark discharge CDI units are used in all racing apps, especially when cylinder pressures are high due to supercharging or very high static compression ratios. I can also believe they may not be as good for a 2 stroke as they are a 4 stroke due to better fuel distribution.
What it sounds like to me is that the capacitor in the wire is essentially "crutching" a weak stock ignition by allowing the charge to build up into a higher energy spark and then discharging it with so little delay that the stock timing is unaffected. Great idea since this is much cheaper than replacing an ignition box and coil (which would be a more compelling marketing story than their complicated "physics lesson").
Theory aside, I was convinced by a friend's experience with it to install one on my bike. His experience on his thumper was it made it start first kick every time vs. 3-4 minimum. In addition, at one point after installing the HotWire he took an old, previoulsy fouled plug, put it in, and rode ~10 miles. He then pulled it and it was nice and clean, just like a fresh plug!
So I just installed it and have yet to ride the bike for more than a quick test loop around the block. So far all seems the same, but I'll report back after a full day of dirt riding.
I've now ridden the bike offroad and it pulls really strong from idle to the REV LIMITER! Had never hit the rev limiter so wasn't sure at first if I was out of main jet or it was ignition related, but it is the KLX's rev limiter. This is mainly due to the Stroker headpipe/pumper carb combo. I did the mods sequentially and the pumper carb helped, but the headpipe was needed to fully realize its potential. It's the classic hop-up scenario, where you have to improve the whole system to be effective. This is a totally different bike than it was a month ago. Getting on the gas now causes the back end to fishtail out and roost like crazy. Traction is now my problem when I get overzealous with the right wrist!
The HotWire didn't hurt but can't say if it helped since the other components made such drastic improvements. I can say the bike starts first kick now even when hot. Previously I had to crack the hotstart valve to get easy restart, but not now. Also, the bike never stalled, even when riding slow in tight stuff where sometimes it previously quit.
Thus, I'd do it again, at least on a KLX. Again, I believe its real effect is crutching a weak ignition, and based on my previous experiences kicking this thing over even when stock I'd bet the KLX's unit is probably barely sufficient. A bargain when you consider it was less than $40 compared to an expensive new CDI unit.
Mounted the nology hot wire on my XR630 last weekend. The bike started on the first kick & seemed to rev a bit higher, possibly due to better combustion. My bike had a bit of hesitation when you crack the throttle open quickly (as do most 4-strokes), and that's all but eliminated.
The long-term reliability of the wire is my only concern now, so I carry the original spark plug boot just in case I need to make a trailside repair.
BTW, I ran a resistor plug because that's all I had. They recommend a non-resistor plug. I plan to switch plugs before the next ride.