Mini Modified Tractors
Class Rep.  Larry O'Connor
Weight not to exceed 2100lbs
1.        All Mini Modified Tractors must have working brakes on both rear wheels.
2.        No portion of the Mini Modified Tractor shall exceed eight feet forward of
the centerline of the real axle and not to exceed six feet in width.
3.        Tire size is 18.4” x 16.1” only.  No radials allowed.
4.        Automatic transmission vehicle must have a reverse lockout.  S.F.I.
approved transmission shield is mandatory.
5.        All standard transmission equipped super rods must have a S.F.I.  equipped
clutch and flywheel and steel bell housing complete with 1/8” block plate and a 90
thou thick liner. Owner must sign a guarantee of compliance and verification form.
6.        All Mini Modified Tractors must have a switch that will allow starting in
neutral or park only.
7.        Fenders on all Mini Modified Tractors must be constructed so that no part of
the driver’s body can come into contact with rear tires.
8.        Minimum drawbar length is 6” from the center of rear axle to the point of
9.        Maximum height of drawbar is 13” from top of the hitching device to ground.
10.     The hole size in drawbar must be a minimum of 1 ½” diameter and minimum
thickness of 7/8” cross section.
11.     A draw bar cable is mandatory.
12.     All Mini Modified Tractors must have a roll cage of at least four point attachments to the
frame.  Minimum cage tube to be 1” diameter.  Cage may be welded or bolted on with a minimum
of four 1/2:” grade eight bolts.  Roll cage must protect upper body of the driver.
13.     Steering rotation must be controlled safely with either a manufacture steering box or rack and
14.     All seats must be securely fastened.
15.     Weights must be securely fastened on brackets and not extend rearward beyond the rear tires.  
Weights must not obscure hitching procedure.
16.     All Mini Modified Tractors must have two turn over bars that must support the
vehicle and be at least 3 x3” and be no less than 5” beyond rear most point of the tire and no
more than five inches above the ground.  No Wheels.
17.     All drive shafts and yokes to be completely shielded 360 degrees the full length of
shaft and be a minimum thickness of ¼” metal and securely mounted with grade eight bolts.
18.     Wheel studs to extend through wheel nuts on rear wheels.
19.     Maximum engine size is 500 cubic inches.  8 cylinder engines only.
20.     All engines to be naturally aspirated, wedge head and cast iron block.
21.     No electronic fuel injection allowed.  Gasoline or M1 alcohol engine only, no
diesel designed engines allowed.
22.     Electric fuel pumps are allowed but must be wired to a kill switch.
23.     No mechanical driven fans allowed.
24.     All engine exhausts must exit upwards and be a minimum of 12” above the
bend in the pipes and no more than 10 degrees from vertical.
25.     S.F.I. approved balancer bolted to the crankshaft is mandatory.
26.     Stock valve cover bolt pattern cylinder heads only.
27.     Four point seatbelts mandatory and must be properly attached during pull.
28.     Fire suit of minimum one layer and neck-brace is mandatory.
29.     SNELL 2000 approved full face helmet balaclava and S.F.I. gloves mandatory.
30.     Leather boots or S.F.I. approved boots required.
31.     Fire extinguisher mounted on vehicle must be compatible with fuel used.
32.     Engine outside shielding must extend from the base of the cylinder head to 2” below
crankshaft centerline.  Must be a least 1/8” metal and the full length of the block.  Frame allowed
as shield.
33.     Throttles to be a positive two dead man type.  All foot throttles must have a toe strap.
34.     Mini Modified Tractors must have an automatic-type white light on the dashboard and
one within 6” of the kill switch to indicate when the vehicle is in the reverse position.
35.     All Mini Modified Tractors must have an emergency kill switch that will kill the engine in the
event of breakage.  With a ring on the switch, no less than 2” in diameter located at the rear of the
36.     Battery disconnect switch required.
37.     S.F.I. flex-plate required in automatic transmission vehicles.
38.     All Mini Modified Tractors participating in a OTTPA event will follow both the
general and safety rules as outlined in the OTPA Rule Book.