FOR ALL PRD125CC CONTROLLED TAG CLASSES

EFFECTIVE IMMEDIATELY

In February 2012, the PRD factory released the “Easy Start Ignition System”.  Since the release we have experienced some difficulties.  The two areas of concern are the coil and the CDI, the coil proving to . . . → Read More: ]]> PRD-USA MANDATES SPEC SPARK PLUG AND CAP

FOR ALL PRD125CC CONTROLLED TAG CLASSES

EFFECTIVE IMMEDIATELY

In February 2012, the PRD factory released the “Easy Start Ignition System”.  Since the release we have experienced some difficulties.  The two areas of concern are the coil and the CDI, the coil proving to be the key issue.

PROBLEMS

Coil:  For no apparent reason a perfect working coil stops working completely or starts to misfire at top RPM’s.  At times a coil that would not function with one type of spark plug would function with a different type.  In an effort to correct these symptoms a new coil would be installed but in some cases the problem reoccurred.

CDI: For no apparent reason the CDI would loose spark.  In most cases turning the system “off and on” resets the CDI allowing it to function properly.  In some cases the CDI would not reset therefore replacing the CDI was required to resolve the spark issue.  The major problem here is if you took a failed CDI off one engine and put it on another engine it often worked properly.

Because in both instances we could not detect a single point of failure or repeatable constant we have spent innumerable hours testing, countless hours with Denso and NGK engineering departments, the PRD factory, as well as individuals heavily involved with Rotax, discussions with Mike Speed and many others.  We found the following:

Both problems appear to be a result of a non-resistor type spark plug which is over gapped such as the “51 plug” which we will use in the following explanation.

1.  How might the “51 plug” affect the coil?

All coils have a maximum operating output.  When the coil is used at or above maximum output for extended periods of time, the coil degrades and is unable to produce an adequate charge to the plug.  The “51 plug” requires 40,000+ volts to operate in the current configuration used.  This high level of output degrades the coil and eventually causes it to either fail completely or first miss at top RPM’s then fail.  In some cases replacing the plug with a different type, such as a “BR10 plug”, the engine will fire and work properly as this plug only requires 18,000 volts which the degraded coil can still produce.

The solution is to install a resistor type plug which requires less voltage to operate properly such as the “BR10 plug” at the manufacturers recommended air gap.

2.  How might the “51 plug” affect the CDI?

The “51 plug” is not a resistor type plug, so random high frequency noise escapes and signals the CDI to go to the fail safe protection mode which shuts it down.  That’s the reason turning the system off and on again will reset the “fail safe” and a CDI will function properly on one engine but not on another.

The solution is to install a plug such as the “BR10 plug” which is a resistor plug and thereby absorbs the noise.  This plug substantially reduces the release of random high frequency noise.

Given all this information and testing, we have concluded the majority of coil failures and problems experienced with the CDI are a result of over gapped, non-resistant type spark plug such as the “51 plug” used in these examples.  In order to resolve these issues PRD-USA is mandating a spark plug and resister cap specification for All PRD 125cc Controlled Tag classes effective immediately.  This includes both ignition styles.  The follow items will be part of tech:

Spark plug: NGK standard BR8EG, BR9EG or BR10EG.

Spark plug cap: Must be marked with “NGKTB05EMA” or “NGKLB05EMH”

Spark Plug gap: Maximum spark plug gap .025”

With exception to the gap the spark plug is to be unaltered.

Although this tech rule is sudden the change is imperative to the success of the PRD program, but more important, it brings resolution to the customer/karter who has or otherwise would experience a problem with the PRD ignition.

F.Y.I.  The spec plug is not a new concept, Rotax previously mandated a low voltage resistor type plug.

karts around to take the green at Sunday’s 3rd Round of the LAKC.

Erik Jackson went on to win the final followed by Cris Araujo and Lloyd Mack

The Spec PRD Program . . . → Read More: huge prd turnout at Lakc]]> #86 Erik Jackson and #09 Cris Araujo bring the SR PRD field of 18

karts around to take the green at Sunday’s 3rd Round of the LAKC.

Erik Jackson went on to win the final followed by Cris Araujo and Lloyd Mack

The Spec PRD Program has made a home for racers of all ages. LAKC offers five PRD classes consisting

of PRD JR I, PRD JR II, PRD Spec Senior, PRD Pilot Program and PRD Grand Masters

Round 4 of the So-Cal Sprinters 2012 season brought fun in the sun for 40 plus competitors at

Adams Motorsports Park in Riverside California Saturday April 28th 2012.  Pictured: #8 Hannah Grisham

leads the JR II PRD TaG Controlled all the way to victory with . . . → Read More: Spec PRD featured at So-Cal Sprinters April Club Race]]>

Round 4 of the So-Cal Sprinters 2012 season brought fun in the sun for 40 plus competitors at

Adams Motorsports Park in Riverside California Saturday April 28th 2012.  Pictured: #8 Hannah Grisham

leads the JR II PRD TaG Controlled all the way to victory with #78 Henry Falls-Hand in close pursuit.

Bret Morland Running PRD Fireball On His Sprint Sit Up @ Big Willow

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Easy Start System Install PDF