· Weight Class: 1050 lb.
· Age limit on class participation: 9 years old and/or physically capable of being in full control of their tractor at all times unassisted.
· Flathead engine with stock appearing block Maximum bore 3.830”
· Maximum stroke 3.25
· cubic inches maximum Open valve size
· Billet heads allowed
· Stock appearing Kohlertype carburetor with a maximum venturi of 1.200”. No air entering after the 1.200” air restriction. Venturi must be round in shape. No slides, no injection, naturally aspirated only. Standoff pipes or ram tubes are permitted
· Wheelbase: 56” maximum
· Stock Altered Twins are allowed to run in this class under the following rules:
· Stock engines (block, stroke, heads). Engine size must not exceed 39 cubic inches for OHV or 48 cubic inches for flathead twins.
· Stock carburetors may be reworked. OEM accelerator pump carburetor is allowed. OEM Kohler 2-barrel carburetor and recast 1.200” stock appearing carburetors are allowed. No other types of carburetors allowed. Maximum one (1) carburetor allowed. No turbos or pressurized intakes.
· No reverse port engines allowed. Manifolds and carburetors must go to the original stock ports
· Stock heads may be reworked, but recast or aftermarket heads are NOT allowed. Porting and polishing is allowed. No external welding or other external modifications allowed. Must use stock intake and exhaust bolt pattern and location.
· Aftermarket cams, pushrods, valve springs and solid lifters allowed. Roller lifters and roller rockers are allowed. Engine must have been available in a lawn or garden tractor from an OEM manufacturer not to exceed any other rules such as horsepower, cubic inch, cylinders, or class size rules, ect., and must be OEM stock production garden tractor engine. Aftermarket blocks are not allowed. It is up to the tractor owner to provide documentation to prove eligibility, such as OEM tractor manufacturer, tractor model, and engine specs such as cylinders, cubic inch, and horsepower rating.
· Fuel: Alcohol or gasoline is allowed. No Nitrated or Oxidized fuels allowed.