2019 Class Rules

Classes 
1050 Lb. Stock 
1150 Lb. Big Stock                             
1150 Lb. Pro Modified 
1300 Lb. Bike (650cc & 1350 cc)                      
1500 Lb. Mini Rod 4-cyl 
1500 Lb. Modified 4-cyl 
1700 Lb. Econo Modified 8-cyl                       
2000 Lb. Modified 8-cyl 


1050 Lb. Stock
1.Stock engine only not exceeding 14 HP and 32 cubic inches from the OEM,     Maximum .030" over bore.
2.0.330 Maximum cam lift.
3.Maximum 1" venture carburetor. 
4.Throttle to be run through a working governor, 4000 rpm maximum.
5.Porting and polishing is not allowed.
6.Gasoline or diesel only.
7.Maximum tractor length shall not exceed 6'6" from center of rear     axle.
8.Tractor must have hood and grill.
9.Maximum drive tire size: 23x10.5x12.
10.Transmission gear ratio changes allowed.
11.Drivers up to 17 years of age and/or High School.

1150 Lb. Big Stock
1. Single or Twin cylinder, complete stock motor only not exceeding 25 HP     from the OEM.
2. 0.330 Maximum cam lift on flathead engines and no more than 10% over     OEM stock V-Twin cam lift.
3. Maximum 1" venture carburetor.
4. Air cleaner and filters are optional.
5. Throttle to be run through a working governor with factory or man made     positive stop mounted on engine block (no slippage), 4000 rpm maximum.
6. Stock bore and stroke, cylinder must not exceed 0.030 over the original bore     diameter.
7. Stock valve diameters only for block being used.
8. Porting and polishing is not allowed.
9. Gasoline or diesel only
10. Maximum wheelbase is 52" with the front axle not to exceed the     forward most part of the frame, whichever is less.  Maximum tractor length is     6'6" as measured from center of rear axle to farthest most forward point.
11. Tractor must have hood and grill.
12. Maximum drive tire size 26x12x12
13. Tractor must have stock rear-end of a lawn and garden type.
14. Transmission gear ratio changes allowed.
15. Tractor must use stock garden tractor type frame, only modification for     engine change allowed.

1150 Lb. Pro Modified 
1.Any combination of engines allowed, excluding automotive, motorcycle,     snowmobile or ATV type engines. 
2.Gas, alcohol, or diesel only. Propane injection allowed on diesels only, see     rule # 6 under "Tractor" in General Rules.
3.Turbochargers allowed on diesels only.
4.Maximum tractor length shall not exceed 6'6" from center of rear axle. 
5.Maximum tire size: 26x12x12.
6.All other modifications allowed.
7. 3/8 safety cable on hitch

1300 Lb. Motorcycle (Small Bike and Super Bike)
Small Bike maximum 650 CC OEM, Super Bike maximum 1350 CC OEM. 
1.Gas or alcohol only.
2.Hood and grill optional.
3.Naturally aspirated motorcycle engines only. 
4.Tractor width shall not exceed 60". Maximum tractor length shall not exceed     8' from center of rear axle.  
5.Maximum drive tire size: 26x12x12.

1500 Lb. Mini Rod 4-cyl
1.Engine must be OEM block not to exceed 4 cylinders.
2.Gas, alcohol or diesel fuel only. 
3.Tractor width shall not exceed 60". Maximum tractor length shall not exceed     8’ from center of rear axle.
4.Maximum drive tire size: 26x12x12.
5.Drivers in this class must be at least 14 years old or driver must be old enough     to handle the tractor. To be determined by TMTPA officials. 

1500 Lb. Modified 4-cyl
1.Engine must be OEM block not to exceed 4 cylinders.
2.Gas, alcohol or diesel fuel only, turbochargers and superchargers allowed.  
    Superchargers must have adequate restraint to prevent blower lift off.
3.Diesel engine tractors only may run any combination of propane     injection, methanol/water injection or nitrous oxide injection as power     adders only. For propane injection, see rule # 6 under "Tractor" in General     Rules.
4.Tractor width shall not exceed 60". Maximum tractor length shall not exceed     8’ from center of rear axle.
5.Maximum drive tire size: 26x12x12.
6.Drivers in this class must be at least 14 years old or driver must be old     enough to handle the tractor. To be determined by TMTPA officials.

1700 Lb. Econo Modified 8-cyl
1.Engine must be OEM block not to exceed 8 cylinders.
2.Naturally aspirated engine only.
3.Gas or alcohol fuel only. 
4.Single carburetor only.
5.No aluminum heads.
6.Tractor width shall not exceed 60”. Maximum tractor length shall not exceed     8' from center of rear axle.  
7.Drivers in this class must be at least 16 years old or driver must be old enough     to handle the tractor. To be determined by TMTPA officials.

2000 Lb. Modified 8- cyl
1.Naturally aspirated engine only.
2.Gas or alcohol fuel only.
3.Maximum drive tire size: 31x15.50x15.
4.A 4 point frame mount roll cage of round or square tubing with .090 wall     thickness and 1 ½" minimum o.d. recommended. Cage must enclose the     driver and be capable of supporting the completion weight of the tractor.     Minimum 4 pt. safety harness recommended. Minimum requirement will be     a roll bar at least .125 thick X 2" o.d., and of adequate height and placement to     protect driver in event of a rollover. Lap belt also required.
5.Tractor width shall not exceed 72”. Maximum tractor length shall not exceed     8' from center of rear axle.  
6.Skid Pad/Plate requirement – minimum size will be 3” wide by 8” long with at     least a 15 degree bend at the front of the skid pad, 1/8" steel or 3/16"     aluminum. Skids must be attached to the frame rail on each side and as close     to each front tire as possible without interfering with wheel travel or turning.     Maximum ground clearance not to exceed 2” with the front tire in normal     operating position. OR x .120" mild steel tubing or same material as tractor     frame rails. Front axle support should connect to each frame rail inline and     extend toward front of tractor. Front skid/front axle support should have     radius to prevent digging into track. Front axle support frame should be     strong enough to support front end weight of tractor. Support should have a     maximum of 4" ground clearance. Note: Skid plate must be able to support     weight of the front end when checked with a jack.
7.Drivers in this class must be at least 17 years old.



TMTPA OFFICIALS DECISIONS AND DIRECTIVES ARE FINAL AND TMTPA OFFICIALS RESERVE THE RIGHT TO REFUSE ENTRY TO ANY PULLER OR VEHICLE.

PULLING WITH US IS MORE THAN JUST A DRAG!









Class Numbers  
100 - 149  
200 - 249  
250 - 299  
300 - 399  
400 - 449
450 - 499
500 - 599  
600 - 699  

Texas Minirod Tractor Pullers Association