PRD 125CC CONTROLLED TAG RULES
(2014)
CLASS
AGE
*Junior I PRD TAG Controlled @ 240lbs to 260lbs 8 to 12
*Junior PRD TAG Controlled @ 240lbs
to 260lbs 8 to 12 (attained)
Intermediate
*Junior II PRD TAG Controlled @ 310lbs to 330lbs 12 to 15
*Senior PRD TAG Controlled @ 360lbs to 380 lbs 16 +
*Masters PRD TAG Controlled @ 390lbs to 400 lbs 35 +
* PRD-USA National Class
GENERAL CLASS RULES:
Classes will be run per the TAG
rules of one of the following organizations with the exceptions, clarifications
and modifications listed below. Each
series will establish which organizations rules will be utilized.
International Kart Federation
(I.K.F.)
World Karting Association
(WKA)
ENGINE:
Only engines with US serial
numbers are legal.
All components must be O.E.M.
unless noted.
PRD 125cc water cooled 07
Fireball Engines are legal as homologated.
Note: no mixing of parts from 05 Fireball Engines with
07 Fireball Engines.
TARGET R.P.M./GEAR
R.P.M. is limited in an
effort to increase competitiveness and engine life. The PRD factory representative or race
director, if the factory rep. is unavailable, will call out the gear ratio for
all classes. The specified gear ratio
will be the base gear ratio +/- one tooth.
Each age group has a different target R.P.M., the R.P.M. is established
with a single kart and driver on the track alone, race R.P.M. will be higher.
Junior
I 13,500 to
14,000 R.P.M. APX.
Junior
Intermediate 13,500 to 14,000
R.P.M. APX.
Junior
II 14,500 to 15,000
R.P.M. APX.
Senior 14,500 to 15,000
R.P.M. APX.
Masters 14,500 to 15,000
R.P.M. APX.
TIRES
Junior
I 4:50 Front 4:50 Rear
or 4:60 Front 4:60 Rear
Junior
Intermediate 4:50 Front 4:50 Rear
or 4:60 Front 4:60 Rear
Junior
II 4:50 Front 7:10 Rear
or 4:60 Front 7:10 Rear
Senior 4:50 Front 7:10 Rear
or 4:60 Front 7:10 Rear
Masters 4:50 Front 7:10 Rear
or 4:60 Front 7:10 Rear
CARBURETOR:
Tillotson HL166A, HL166B,
HL166C or HL395A ARV per the I.K.F. and WKA rule books are legal for all
classes.
Junior I
will require the use of a PRD-USA/ RLV filter cup with an air inlet hole of 0.462” no go, the hole will remain as manufactured no
cleaning, de-burring or any other modifications are allowed. O-ring must be used and functional. The
filter cup must be sealed to carburetor.
Junior Intermediate will require the use of a PRD-USA/ RLV filter cup with an air inlet
hole of 0.502” no go, the hole will remain as
manufactured no cleaning, de-burring or any other modifications are
allowed. O-ring must be used and
functional. The filter cup must be sealed to carburetor.
Junior II
will require the use of a PRD-USA/ RLV filter cup with an air inlet hole of 0.877” no go, the hole will remain as manufactured no
cleaning,
de-burring or any other
modifications are allowed. O-ring must
be used and functional. The filter cup
must be sealed to carburetor.
Senior and Masters PRD Controlled may use a filter
cup with a center hole diameter of .880” minimum.
HEAD/COMBUSTION CHAMBER:
Use
of the L.A.D. tool is mandatory for CC’s
Combustion
chamber diameter 54.10mm +/- .2mm
REED/REED CAGE:
Must remain unmodified. Branded Reeds “PRD-USA.COM” as shown in the
PDF are required. The rubber coating on
the reed cage may be surfaced to flat.
OIL SEALS, BEARINGS
& GASKETS:
Oil seals, bearings and
gaskets are non-tech. (Bearings must be
metallic).
CLUTCH/CHAIN COVER:
Chain cover: Only the fully enclosed cover is legal (part number
PRD-7159), those with venting that exposes the ring gear are not legal. Use of a third bearing is prohibited. O.E.M. clutch nut only can be used to start
the engine when using a hand held starter.
PRD gear plate guard:
The gear plate guard must be
installed properly with the ground wire plugged in.
Clutch: The 2010 PRD steel on steel clutch and the 2007 PRD clutch will be legal
through December 2014. January 2015
the 2010 PRD steel on steel clutch will be the only legal clutch for all PRD
125cc Controlled TAG classes.
RADIATOR:
Only radiators unmodified and
hoses as supplied by PRD with the engine are legal.
Water pump must be PRD O.E.M.
and axle driven. The water pump may be
driven directly by the axle.
AIR BOX/INTAKE
SILENCER:
Only air boxes/intake
silencers as supplied by PRD are legal and must be branded PRD or RLV. Only the top two holes of the four hole
airbox may be utilized, the two tubes must measure 22mm +/- 1mm. Only one drain hole is allowed, cannot exceed
0.250” in diameter. The air filter is
optional but recommended.
PIPE/EXPANSION CHAMBER
AND HEADER:
Only pipes/expansion chambers/connectors
as supplied by PRD are legal. Spec pipe
length 16” minimum as measured with a .250” (1/4”) tape from the pipe side of
the exhaust header flange, around the outside radius of the header to the first
weld on the pipe at the major diameter.
Only step connector tubing is legal.
PRD header o-ring cushion may be installed in the header cup to cushion
the flex part. PRD connector wraps may
be used. A ½” +/- wide ring may be added
inside the pipe cup to stop the divergent cone from mushrooming.
IGNITION:
2012: Ignition timing a maximum of
.215” B.T.D.C. (no minimum).
Ignition: Easy Start Ignition System
is legal for all PRD 125cc Controlled TAG
classes.
Pre 2012: Ignition timing a maximum of
.090” B.T.D.C. (no minimum).
Ignition: The
OPPAMA ignition has been discontinued by the PRD factory. To date there are no coils or rotors
available for the OPPAMA ignition. The
OPPAMA ignition is legal for all PRD 125cc Controlled TAG classes through May
1, 2014.
CYLINDER/PISTON:
Cylinder
overall height as measured from machined surface to machined surface 86.80mm
minimum.
Maximum
piston size is 54.25mm, maximum bore is non-tech.
SPARK PLUG & CAP:
Spark
plug and caps are spec and subject to technical inspection approved plugs and
caps are as follows for all classes.
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”. The spark plug base gasket must be in place unless a
temperature lead is used.
With exception to the gap the spark plug is
to be unaltered.
ELECTRICAL SYSTEM/BATTERY:
All
electrical components must remain OEM and unmodified.
Battery:
The PRD-YUASA/VRLA-YT7B-BS along with the Kartsport battery
are both legal for all PRD Fireball 125cc Controlled TAG classes.
CYLINDER LEAK DOWN TEST
(mandatory):
All
PRD classes are considered “Restricted Classes” (air leakage can cause an
increase in performance). This test is
used to detect excessive leakage through the engine, engine seals and
carburetor. The location of the leak is not
important. The test measures a percent
of leakage. The engine will not be legal
if the maximum leak percentage is exceeded irrespective of where the leak
occurs. The cylinder leak down test is
performed as follows:
RESTRICTED
ENGINE LEAKDOWN TEST
Parts required:
Cylinder leak-down tester
(available
from Napa Pt
#SER-CLT2 & Harbor Freight Pt # 94190)
Calibration tool (available from PRD
distributors)
Header plug (available from PRD
distributors)
Filter cup rubber boot (available from
PRD distributors)
Carburetor plug (available from PRD
distributors)
TECH
INSPECTOR:
Make
sure there are no leaks at the installed plugs or the exhaust gasket. Leaks at these areas should be fixed prior to
the test.
Calibrate
your cylinder leak-down tester. Install
the calibration tool to the output side of the tester. Raise the pressure on the primary gage to ten
(10) pounds. Read the secondary
gage. This is the maximum leakage
percent allowed with this gage. This
number will vary from gage to gage.
1. Remove
the pipe and flex connector from the header.
2. Install
the header plug in the header outlet and tighten.
3. Cadet,
JR I, JR Intermediate and JR II:
- Place the rubber boot over the filter cup and
tighten the hose clamp.
SR
and Masters:
- Install the carburetor plug in the carburetor
inlet.
4. Remove
the spark plug and locate the piston at the bottom of the stroke.
5. Screw the outlet hose of the leakage tester
kit in the spark plug hole and connect all hoses in the kit including the hose
with the gauges.
7. Attach
the air line.
8. Set
the initial pressure low.
9. Turn
the regulator until the primary gauge is set on 10 pounds.
10. The maximum leakage gauge reading is the
percent the calibration tool indicates. Any
reading above that percent the leakage is illegal.
PRO RACING DESIGN 125CC CONTROLLED TAG CLAIMING RULE
Person claiming the engine
i.e. making the claim must:
a. Be entered in the class.
b. Race the class.
c. Have raced
the class at this current specific series or venue no less than twice
previously (eligible to claim in race 3).
A participant may only claim
one time per calendar year in each club program, series or venue. The manufacturer or importer reserves the
right to claim any engine at any time, anywhere with no exception, including
National and Grand National events. This
claim will hold preference over all other claims.
Any participant in this
claiming class must agree to the current claiming rules of the class. If the participant fails/refuses to surrender
the claimed engine, the participant will forfeit all points and will be
ineligible to compete in the class for the remainder of the current venue or
series program.
Engine claiming will be made to
only one race official designated by the series. The claim must be made in writing within 30
minutes after the end of the race the engine is being claimed from. We recommend either the Race Director or the
Chief Technical Official. If more then
one participant claims the same engine, the participant with the lowest point
total of the series or venue will be awarded the claim. The engine being claimed must pass post race
technical inspection.
Please be advised, as a
result of the claimed engine passing post race technical inspection it is not
implied nor a guarantee the claimed engine is legal or will pass future
technical inspections “let the buyer beware” engines are claimed as is.
After post race inspection:
a. The person claiming the engine i.e. making
the claim will present the Chief Technical Official $1,800.00 either in cash or
a certified cashier check.
b. If the claim
is made by the manufacturer, importer or agent of either, that person will
present the Chief Technical Officer with a new engine (including all parts
listed in “c”) and $400.00 cash.
c. The present engine owner will present the
Chief Technical Official with the claimed engine less the carburetor. The engine will include:
1. Reed manifold with reeds
2. Exhaust header
3. Intake manifold
4. Ignition
5. Complete clutch with cover
6. Starter with bendix
The Chief
Technical Official will then complete the exchange.
INTENT OF RULES
All of these rules are
written with the intent of creating an affordable engine package that can be
used from Junior I all the way through Masters.
