Below: high performance modified stock ATC250R ignition system
Ignition test stand, full operating test of 250 R ignition and electrical
system including flywheel
ATC250R Ignition System - Modified Stock System
The ignition system is critical to any vehicle, spark misfire
or weak spark robs the engine
of power, causing overheating and cylinder damage. If the ignition misfires 1 out of 5 times
the engine loses 1/5th of its power. That reduces a 50 hp engine to 40 hp.
Motorcycles are bad for electrical and ignition system
mostly due to bad
wiring. A loose terminal on the CDI plugs on the 250R will cause hard starting and
poor running - it happened to mine.
The stock ignition system, if working correctly is OK for
engines near stock.
A big mistake many make is to modify the engine and fuel system but ignore the
ignition system - the part that makes it all work!
Theres plenty of extra "grunt" in the stock system if its
modified. Modifying the
stock system has lots of advantages:
1.) No need for an expensive CR system that doesn't do much
than the ATC ignition
2.) Original mounting
3.) Good for those that have to race in "stock class" - uses the original parts
What are the mods?<> An increase in spark voltage as shown in the graphs, graph data is calculated
These modifications result in an approximate spark
energy gain of 30%.
Notice that the spark voltage is about the same near idle,
the stock system
loses voltage rapidly as engine RPM increases.
What kind of performance gains can I expect?
The same ones I saw. My ATC250R went from "can't pull the
wheel" with a dull
orange spark, to pulling the front wheel in 2 gears. It almost slid me off the seat first
time I hit the gas.
Increased ignition energy can reduce the carburetor jetting,
resulting in a cooler running
engine, less cylinder wear, less fuel consumption. Carb retuning will probably be needed.
What's all this stuff about spark "energy" and "voltage"
Really simple, physics says that:
Electrical power = voltage x current
A 55 watt headlight = 12 volts x 4.6 amps current
Successful ignition of an A/F charge takes both a good strong
voltage spike to bridge
the plug gap, then a healthy dose of current to sustain the spark.
The modified 250R ignition system does both.
What about other "ignition boost" devices?
These do not increase ignition energy. Some like the
only change timing by altering the ignition pickup. The "spark plug capacitors" that
have been advertised as high as $200.00 do not increase spark energy, they increase
spark current with a loss of spark voltage.
Some gimmicks like the Splitfire spark plug simply give a set
of sharper or finer electrode
points for the spark to arc from; this is well known to electronics, but it doesn't cost up to
$8 a plug to do, you can do it to any spark plug.
Gimme the details!
The modification is to both the electrical wiring harness and
A rotor puller tool is needed to remove the rotor and stator.
Carefully pack the entire ignition and electrical system including:
Stator w/pulse coil AND mounting bracket (triangular shaped aluminum thing), rotor, main wiring harness,
CDI, ignition coil, and the last spark plug run in the engine (or if its fouled badly, send a new one)
Remove the Stator bracket by removing the 3, 8-mm screws from the engine block. Dont send the 8mm scrwes.
Wrap the stator in newspaper, put it inside the rotor, put the pickup coil inside the stator. Wrap the bundle in at least
2 inches of insulation. Carefully pack all the other parts in the same box so the rotor cant bang against them.
Send the whole works Insured Mail. When I receive it, I will:
How much?$ 100.00 US Dollars plus return COD fees. Postal COD includes Insurance.
Add $50.00 for headlight. NOTE - increased ignition power
when headlight is OFF
for systems that include headlight.
See this link for shipping information and links to the Post Office web site: