This is an on-line version of the Official rule book of the NATIONAL BOAT RACING ASSOCIATION. This rule book is provided to ensure the utmost and fairness in competition is observed. If you find anything needing changed or corrected, or have any question on, or misunderstanding of a rule, please contact your state director or the National Office. Be sure to read and understand the rule book thoroughly before entering into an NBRA sanctioned event.
NBRA HISTORY
On November 3, 2001 the name, NATIONAL BOAT RACING ASSOCIATION, was proclaimed and will remain in our hearts, that for kneel down boat racers across the waters of this nation, that we still have the rights as mature adults, not to have the wishes of others crammed up our exhaust pipes.
In Kansas City, Mo. on this day in a small room with 35 people wishing to put fun back into boat racing, a new organization was formed. Officers were elected, a race schedule prepared, a new motor was adopted(Tohatsu M50D2) and class structure was developed with 15 classes. All of this and much more was done with harmonious decisions by racers representing Missouri, Illinois, Iowa, Kansas, Arkansas, Mississippi, and Texas.
IS THIS A GREAT ORGANIZATION TO BELONG TO OR WHAT?
MISSION STATEMENT
"The purpose of the NATIONAL BOAT RACING ASSOCIATION is to, actively promote the sport of Stock and Modified Hydroplane and Runabout boat racing by encouraging and advancing safety, increased awareness in the sport, and expanding its competition"
CLASSES - ENGINES - WEIGHTS
RUNABOUT CLASSES
STOCK ENGINES
A---- YAMATO 80,YAMATO 102,202,302 W/ 20SSH RESTRICTOR PLATE, SIDEWINDER 15H------------390LBS
B---- YAMATO 102, 202, 302, MERCURY/MAINER 25XS---------------------------------------------------------------------------420LBS
D---- MERCURY 44ci, TOHATSU M50D2, MERCURY 44XS---------------------------------------------------------------- 490LBS
NOVICE---- YAMATO 80 W/ RESTRICTOR PLATE, ANY MOTOR 15 HP-15ci OR LESS WITH A
CLUB FOOT, (Removal of tiller handle and addition of a steering bar permitted)
DEAD MAN THROTTLE AND KILL SWITCH REQUIRED.
SUPER STOCK ENGINES
A---- MERCURY KG-4, MARC 15,MERCURY 20H, HOT ROD A, SIDEWINDER 15 w/ANY EXHAUST-----345LBS
B---- HOT ROD B, SIDEWINDER 20 w/ ANY EXHAUST---------------------------------------------------------------------365LBS
OMC & MERCURY B-1 ENGINES, YAMATO 80 MODIFIED---------------------------------------------------------420LBS
D---- MECURY 40ci, 55H------------------------------------------------------------------------------------------------------------------490LBS
E---- MERCURY 44--------------------------------------------------------------------------------------------------------------------------490LBS
SE---- OMC 44-49ci, MERCURY MK75, 650, YAMAHA 50, TOHATSU M50D2
HYDROPLANE CLASSES
STOCK ENGINES
A---- YAMATO 80, YAMATO 102,202,302 w/ 20SSH RESTRICTOR PLATE,SIDEWINDER 15H-----------380LBS
B---- MERCURY/MARINER 25XS-----------------------------------------------------------------------------------------------------420LBS
C STOCK---- YAMATO 102,202,302----------------------------------------------------------------------------------------------420LBS
D---- MERCURY 44,MERCURY 44XS, TOHATSU M50D2-------------------------------------------------------------------440LBS
NOVICE---- YAMATO 80
ANY MOTOR 15HP-15ci OR LESS, OMC 15 w/RESTRICTOR PLATE (see rule 12G)
YAMATO 102,202,302 w/RESTRICTOR PLATE(SEE RULE 12G)
APBA J CLASS RUNNING UNDER CURRENT APBA RULES(SEE RULE 12G)
SUPER STOCK ENGINES
A---- MERCURY KG4, MK 15, 20H,HOT ROD A SIDEWINDER 15 H W/ ANY EXHAUST--------------------340LBS
B---- MERCURY 200, 25XS, OMC 22ci, YAMATO 80 MODIFIED------------------------------------------------------385LBS
HOT ROD B, SIDEWINDER 20----------------------------------------------------------------------------------------------365LBS
C MOD---- MERCURY 30, MERCURY 24.1ci, YAMATO 202,302, MODIFIED 102
YAMAHA 24.1ci(running same rules as Yamato 202,302)
OMC 31.5ci(Built between the years 1976-1999)--------------------------------------------------------435LBS
D---- MERCURY 40ci, 55H------------------------------------------------------------------------------------------------------------440LBS
E---- MERCURY 44-----------------------------------------------------------------------------------------------------------------------440LBS
SE---- OMC 44-49ci MERCURY MK75, 650, YAMAHA 50, TOHATSU M50D2
MOD 25---- YAMATO 202, 302, MOD 102. MERCURY 25 MOD. YAMAHA 24.1ci MOD-------------------400LBS
____________________________________________________________________________________________________________________
NOTE 1 ---- The Technical Committee has the right to equalize competition with a one race notice in any combination classes or classes with multiple engines.
NOTE 2 -- -- Stock and Super Stock classes are combined. (EXAMPLE: D Stock Engines are combined with D Super Stock Engines)
SUPER E RULES
The only legal engines are:
Group 1: OMC 44.9cu. in.2 cylinder 40 to 60 hp Group 2: Mercury 59.4 cu. in. 6 cylinder Mark 75 & 75H Group 3: Mercury67.43 cu. in. and 59.78 cu. in. 4 cylinder, Mercury 650 4 cylinder Group 4: OMC 49.7 cu. in. 3 cylinder, Mercury 650 3 cylinder, Yamaha 6H5 & 6H4 42.6 cu. in. 3 cylinder Tohatsu M50D2 42.5 cu. in. 3 cylinder
INSPECTION 1.Identify engine and which group of inspections applies. 2. Measure cylinder bore and stroke. 3. Inspect reed port openings. 4. Check lower unit "R" Dimension. MODIFICATIONS The extreme differences in configuration and displacement size of these engines makes it necessary to impose certain rules, so as to control the potential horsepower of each engine. The engine block selected, determines which Group it falls under for modifications and specifications. NOTES: 1. There are no restrictions on intake air scoops or length tuning of intake and exhaust systems. 2. No supercharges, turbo chargers, or other similar mechanical devices are allowed. Engines must be normally aspirated. 3. No nitrous oxide or other power boost injection is allowed. See also fuel page 5. 4. Other than the rules and specifications described in this section, there are no technical limitations modifications of Super E engines. There are no specifications or restrictions on porting, reciprocating or rotating parts as long as the bore and stroke stroke criteria are met. 5. Lower units; There are no restrictions except gear housing shall have a minimum "R" Dimension of 1.850 inches. No tractor units. 6. The Racing Commission has the authority to change, disapprove, or approve rules which violate the spirit of this class.
GROUP RULES GROUP 1: OMC 44.99ci 2 CYL MOTOR CUBIC INCHES - 44.99 NUMBER of CYLINDERS - 2 BORE +O.O70 - 3.187 STROKE =/- 0.010 - 2.82 NUMBER OF CARBURETORS - N/A REED OPENINGS - N/A Except for bore and stroke limitations, these power heads are basically open for modifications. There are no restrictions on placement, size, or number of intake ports, reeds and carburetors. Additionally, there are no restrictions or specifications on reciprocating and rotating parts. Must meet both bore and stroke criteria.
GROUP 2: MERCURY 59.4ci 6 CYLINDER MOTOR CUBIC INCHES - 59.4 NUMBER OF CYLINDERS - 6 BORE +0.070 - 2.44 STROKE +/-0.010 - 2.125 NUMBER OF CARBURETORS - 3 REED OPENINGS - N/A RESTRICTIONS APPLY TO THIS MOTOR ARE AS FOLLOWS: A. MUST MEET BOTH BORE AND STROKE CRITERIA B. NO REMOVAL OF CYLINDER HEADS C. AIR/FUEL MIXTURE MAY ONLY BE INDUCTED VIA 3 CONVENTIONALLY MOUNTED SINGLE BARREL CARBURETORS. D. REED CAGES MUST BE CONVENTIONALLY LOCATED.(No specifications apply. Any make, type or size is legal) GROUP 3: MERCURY 62.43ci / 59.78ci 4 CYLINDER MOTORS CUBIC INCHES - 63.43/59.78 NUMBER OF CYLINDERS - 4 BORE +0.070 - 2.875 / 372.5 STROKE +/-0.010 - 2.602 NUMBER OF CARBURETORS - 2 REED OPENINGS - 4 RESTRICTIONS APPLYING TO THIS MOTOR ARE AS FOLLOWS: A:MUST MEET BOTH BORE AND STROKE CRITERIA B:AIR/FUEL MIXTURE MAY ONLY BE INDUCED VIA 2 CONVENTIONALLY FRONT MOUNTED SINGLE BARREL CARBURETORS C.REED CAGES MUST BE CONVENTIONALLY LOCATED WITH THE SAME NUMBER OF PORTS AS SPECIFIED BY THE MANUFACTURER.(NO SIZE OR MEASUREMENT SPECIFICATIONS APPLY) GROUP 4: OMC 49.7ci 3 CYLINDER / MERCURY 49.9ci 3 CYLINDER / YAMAHA 42.6ci MODELS 6H5 AND 6H4 / TOHATSU 42.5ci 3 CYLINDER MOTORS CUBIC INCHES - 49.7 / 49.9 / 42.6 / 42.5 NUMBER OF CYLINDERS 3 / 3 / 3 / 3 BORE +0.070 - 3.0 / 2.875 / 2.638 / 2.677 STROKE +/- 0.010 - 2.344 / 2.564 / 2.598 / 2.520 NUMBER OF CARBURETORS - 3 / 2 / 3 / 3 REED OPENINGS - N/A / N/A / 4 / 4 RESTRICTIONS APPLYING TO THESE MOTORS ARE AS FOLLOWS: A:MUST MEET BOTH BORE AND STROKE CRITERIA B. NO ADDITIONAL REED CAGES OR CARBURETORS ARE PERMITTED OTHER THAN THE NUMBER SPECIFIED BY THE MANUFACTURER. C.NO OTHER MEANS SHALL BE USED TO INTRODUCE FUEL/AIR MIXTURE INTO THE CRANKCASE OTHER THAN THE SERVICE CRANKCASE AND SERVICE CARBURETORS SUPPLIED BY THE ORIGINAL MANUFACTURER. D.REED CAGES AND CARBURETORS MUST BE CONVENTIONALLY LOCATED. NO SIZE MEASUREMENT SPECIFICATIONS APPLY TO EITHER. E.MATERIAL MAY NOT BE ADDED TO THE ENGINE TO INCREASE THE SIZE OF THE REED CAGES. HOWEVER, MATERIAL MAY BE REMOVED TO DO SO. F. MATERIAL MAY NOT BE ADDED TO THE CARBURETOR TO GAIN A SIZE ADVNAGE.
