Super Modified Class

AGE GROUP: 18 years

MAX ENGINE: Max 18hp or 40ci OEM rated OHV or 42 ci maximum flathead coming from the lawn equipment origin (4 cycle engines).  No fuel injection.
All engines: custom made exhaust headers, velocity stack, aftermarket air filters.  Must have on board starting systems, electric start or recoil pull start.
Mandatory billet aluminum flywheels.

OHV ENGINES-OHV engines 23ci and up: internal modifications allowed
-External shields and intake manifolds must remain stock.
-OHV engines 22ci or less refer to flathead twin rules.
-Flat head single cylinder 28ci or less: internal modifications open, mandatory billet flywheel.

NOTE:  IF the rules don’t say you can do it, YOU CAN’T!  Engines are 100% stock except for mentioned modifications.

FLAT HEAD TWIN ENGINES: 
-42ci max displacement, factory oversize pistons used to repair engine accepted
-internal modifications allowed USING OEM PARTS ONLY
-larger carburetors allowed as long as they are from lawn tractor origin.
-dual carburetors not permitted
-custom intake manifolds allowed
-no regrinding of camshafts
-external ignition devices not allowed, cross brands of lawn tractor OEM ignition systems allowed

FUEL:[/b 94 octane pump gas and Race Fuel additives Permitted.

DRIVE TRAIN: Centrifugal clutch, traditional belt clutches allowed.  90 degree gear boxes, jackshaft setups allowed.  All chain guards must be a min thickness of 1/8″ aluminum or steel.

STEERING: Direct steering is mandatory, must use lock nuts on all connections.
WHEELBASE AND MAXIMUM WIDTH: 42″ min wheelbase.  42″ max width.  No more than 3″ of total offset.  (Take a measurement from the centre of your frame to the outside of your right tire and doing the same on the left side. With this the difference should be no greater than 3″)

FRAME: 2″ minimum ride height.    Firewall protection recommended.    Discreet chopping of chassis to install after market clutches, gear box, seats and axles allowed, must retain original OEM wheel base.

BRAKES: Brakes on rear only.  No front brakes allowed

WHEELS/HUBS: Custom steel or aluminium rims allowed.  Custom hubs or spindles must have lock collars or new HD cotter pins to prevent movement

BUMPER/SIDE BARS: Side/crash bars mandatory, see general rules.  Closed loop rear bumper mandatory, see general rules.  Front bumpers optional, must be no farther than 2″ from front of tractor and no wider than the body or hood.