TWIN CYLINDER
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25 HP and under Twin Cylinder & Single Cylinder engine.
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4,000 RPM limit, regardless of flywheel type.
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1,050 pound weight limit.
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26 x 12 x 12 tire size maximum (can be sharpened).
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All stock tractors must be stock in appearance; Officials must approve alterations.
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All engines must have OEM dimensions and specifications noted in these rules.
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Stock Block - can be sleeved; must maintain stock bore no more than .030 over.
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Stock head.
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Stock crankshaft stroke must be maintained.
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Steel cranks allowed.
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Stock valves required.
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After market camshafts permitted.
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Head gasket must be a composition gasket – no copper gaskets.
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Stock carburetor required – venturi to be no more than 1.200" diameter.
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Choke can be removed.
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No intake standoffs allowed – 1 inch spacer maximum.
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No porting or polishing of intake and exhaust areas allowed. Deburring in these areas is permitted.
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Exhaust for all tractors must discharge upwards or towards the rear of the tractor - not out to the side, unless running stock muffler (discretion of officials).
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All flywheel and clutch assemblies must be covered 180 degrees on topside. If you have belts, they must have a safety shield.
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13" hitch height maximum.
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Pump gas or racing gas allowed, no alcohol or nitro.
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Canister type coil, no high performance alterations (discretion of officials).
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Water cooled engines and overhead valves permitted.
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60" Wheelbase max.
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Dead Man throttle (must return to idle automatic).
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Must have working kill switch with 2 inch ring.