rules_sportsman600

Sportsman 600

The Sportsman 600 class is founded utilizing the following theories that have proved true over several racing venues.
1.	Manufacturer's offerings of trail machines no longer readily transpose into ice oval snowmobiles. In the process of lowering, many suspension components are either defeated, rendered poorly operational, etc. Spring rates, geometric points, and other key engineering items are overcome, lost or displaced. Modern sleds are either designed for comfort and long travel in trail applications (most) or dedicated as snow cross purpose built units, which although powerful, do not lend to oval application.
2.	An ongoing effort which has been with oval racing for several years is involving new riders, a so-called entry-level class. Various attempts at this have been tried in several associations across the U.S. and Canada. Trail Stock, a recent effort had some success, but became a difficult class to police in the Midwest, as the competitors involved understood the needs of lowering and suspension placement issues for performance, and in turn did not like the requirement of almost full travel, limited traction, and in reality new high dollar equipment to be competitive.
3.	The third and perhaps most outstanding requirement of any entry level class that encourages mass participation, has been affordability.
With these particular concerns in mind, the following criteria has been developed to create a new class that offers affordability, creativity, and excitement, while utilizing proven methods and equipment to provide a platform from which to build.
SPORTSMAN 600 is defined as a 1983 to 2000 production snowmobile, and is further broken down into the following criteria:
A.	Race sled description
	1.	1983 to 2000 production Arctic Cat, Ski Doo, Yamaha, or Polaris snowmobile, of 600 cc engine volume or less.
B.	Sled must retain the following:
	1.	Original tunnel and bulkhead for the model
	2.	Original type engine for the model.
	3.	Front suspension concept must remain as produced, (i.e. trailing arm, strut, a-arm, etc) but may be altered in the following manner:
		a.	Original springs may be altered or replaced
		b.	Original shocks may be replaced, or altered, aftermarket shocks are allowed.
		c.	A-arms, trailing arms, struts, may be changed but must be OEM for the brand.
		d.	OEM for the brand torsion bars may be altered to fit the chassis being used.
		e.	Limiters and other methods of travel restriction are legal, but he snowmobile must have 2 (two) inches of useable front travel minimum.
	4.	Rear Suspension must be OEM for the brand.
		. 1. Rear suspension may be altered in the following manner:
		a.	Shocks may be altered, removed, or rendered inoperable as needed.
		b.	The suspension must bolt to the chassis within the confines of the original mounting plate reinforcements of the chassis selected.
		c.	Suspension springs may be replaced with non-OEM springs.
		d.	Aftermarket shocks may be used.
	5.	Track
		1.	Track may be OEM for the brand, or any R rated track that is no higher in lug height than the original production tracks available for the model, as filed.
		2.	Tracks may be no longer than 133 inches
		3.	Tracks must be 15 inches wide production tracks or designated replacements. They may not be narrowed from production specs.
		4.	Tracks narrower than 15 inches may not be used even if available from the original equipment manufacturer.
	6.	Bulkhead and Tunnel
		1.	Bulkhead must remain in original orientation to the tunnel.
		2.	Chaincase, jackshaft and front drive axel placement must all remain OEM for the model
		3.	Front suspension mounting points within the bulkhead may be reinforced but not relocated.
	7.	Engine
		1.	Engine must remain OEM for the Brand and Model. One, two or three cylinders, 2 cycle only .
		2.	The following engine components may not be modified:
		a.	Cylinders, no porting allowed, overbore of .040 allowed
		b.	Heads
		c.	Crankshaft must retain original stroke
		3	The following items are allowed for builder efficiency and affordability considering the age of the equipment utilized.
		a.	Crankshafts may be welded for repair.
		b.	Aftermarket rods and bearings may be used
		c.	Aftermarket wristpins and wristpin bearings may be used
		4	Ignition must be OEM for the model.
		5	Exhaust must be effectively silenced, but maybe modified or changed.
		6	Carburetors and intake system must remain OEM for the engine and model.
		a.	The only allowable tuning components for the carburetors shall be OEM type jets, slides, needles, etc. No aftermarket enhancements allowed
		7	Air boxes may be modified or removed.
		8	Engine mounting plates must remain OEM, but the isolation devices (mounts) may be replaced
		9	All belts, hoses, wire looms, cables, controls and gaskets may be replaced.
	8.	Brakes
		1.	Brakes must remain OEM for the model.
		2.	If a model has mechanical brakes, hydraulic replacement components are allowed but must be used in the original location at all points. (Master, Caliper, and Disc)
	9.	Clutches
		1.	Clutches both drive and driven must be OEM for the brand but may be replaced, or updated.
		2.	Aftermarket, springs, helixes, cams, arms, weights, bushings, etc may be used.
		3.	No additional machining to the clutch surfaces will be allowed. (Drive and Driven)
	10.	Ski's
		1.	Any legal ski may be used.
		2.	Sled must not be wider that 45 inches at the outside of the skis.
	11.	Traction
		1.	All traction and steering aids shall conform to general rules.
	12	Hood, Belly Pan and Seat The competitor is encouraged to retain the original appearance of the OEM model, color not withstanding. Replacements for hoods must be original type materials and not lightweight versions, even if original type material. Belly pans may be aftermarket replacements. Seats may be reupholstered but must be OEM for model. They may be contoured for comfort and safety. Side bolster pads may be added.
	13.	Bumpers Bumpers may be removed, added, modified, or replaced.
	14.	Fuel tank Fuel tanks must be in original position, and must be inspected for safety concerns. No leaks, improper line routing, or damaged tanks or caps will be allowed.
	15.	Fuel Fuel allowed shall be all fuels deemed legal per the fuel testing standards defined within the ISR rulebook.
	16.	The sleds shall comply with all general and safety rules defined in the ISR rulebook.
	17.	F-500 machines are legal to enter this class at any time but must conform to the following Sportsman 600 rules: Hood and pan must match and must appear as a 88-92 Polaris 500 Indy snowmobile.
C.	The association may AT ITS DISCRETION purchase ONE OR SEVERAL OF THE SLEDS IN THE TOP 5 (FIVE) IN POINTS at season's end for $3000. If purchased the sled/sleds will be sold to a new competitor for participation in the next season. These rules have been developed to allow the greatest amount of creativity, affordability, and participation in the class. The model year's chosen offer the greatest adaptability to oval competition, while still retaining a modern technical concept. The efforts of the class are to create a viable class with a high level of participation, while not construing the image of a vintage class. Availability of equipment needed is vast and affordable; much of it, if properly researched, may be already prepared, and retired from competition at the professional level.
	1.	Effective 4-12-07 the rules for this class are frozen for a period of 3 years. (4-12-2010)
Amended 4-5-05 Board Action 4-3-05 Amended 4-12-07 On board action of 3-25-07 Clarified section 5-11-07 JLK Click Here For Printable Version

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