Classes

MSDRA Trail Stock

Trail Stock is an entry level class for the "recreational racer".
It is intended to allow the competitor to race his/her snowmobile just as he/she rides it on the trail. The use
of an aftermarket "silencer can" is allowed for racing, even though illegal for trail riding in Maine. You will not
be allowed to bump up into MSDRA Stock classes from Trail Stock.

440cc (max)
500cc (max)
600cc
4-stroke 3 cyl
700cc
4-Stroke 4 cyl
800cc
900cc
1000cc
Open

* Must be a registered trail sled.
* No performance changes of any type allowed unless specified.
* Internal carb tuning parts may be changed. Stock air box must be retained but may have minor alterations.
EFI tuning boxes allowed.
* Any stock type clutch tuning parts allowed. 5000 max. engagement.
* Gearing may be changed.
* Aftermarket exhaust silencer cans allowed. Pipes must be OEM stock for model. No pipe mods.
Aftermarket exhaust Y-pipes allowed.
* Aftermarket reeds allowed.
* Cosmetic bolt-on parts are allowed.
* Replacement trail type track allowed - lug height must be min. of .750 inches. Trail type carbide studs only
- NO sharpened studs allowed. No wiper tracks allowed. Stud height maximum .500 inches above lug.
* No sled lowering or strapping down of suspensions allowed.
* Open class: one power adder allowed - turbo, supercharger, NOS. Porting, pipes, big-bores allowed. Must
run on pump gas not race fuel. No meth/ water injection allowed.
* All snowmobiles must have a working tether switch/cord. With the exception of the Open Class, racers will
be allowed a "one event permit" to race without a tether in these classes only.
* All snowmobiles must have a working tether switch/cord, from this class up. No exceptions!

MSDRA Improved Trail Stock

440cc (max)-------------------*650lbs. All
500cc (max)-------------------*650lbs. All
600cc---------------------------*700lbs. (triple) 650lbs. (twin)
700cc---------------------------*750lbs. (triple) 700lbs. (twin)
800cc---------------------------*775lbs. (triple) 685lbs. (twin)
900cc---------------------------*775lbs. (triple) 685lbs. (twin)
1000cc--------------------------*775lbs. (triple) 685lbs. (twin)
* Weight rules not in effect at this time.

* Anything allowed in Trail Stock is allowed in Improved Trail Stock.
* Improved Trail Stock sleds not allowed to bump up into CMSRA Improved Stock classes.
* Trail porting, aftermarket heads, reeds, trail pipes and mufflers allowed. Cylinders must be OEM.
* Carbs must be OEM. ( original for model )
* EFI sleds are allowed to have fuel control boxes.
* Track and stud rules are same as in Trail Stock.
* No sled lowering or strapping down of suspensions allowed.
* Factory "sno-cross" limited build, stock race sleds must run in the Imp. Trail Stock class.

MSDRA Stock

This is a stock class intended for the more serious stock snowmobile racer. This class is based on the ISR
Stock class rules. ISR has more specific rules that we follow but are not listed here. The guideline below
lists the major points.

440cc (max)-------------------
500cc (max)------------------- *All snowmobiles must meet ISR
600cc--------------------------- filed weight spec. for model.
700cc--------------------------- +18lbs. added for fuel and studs.
800cc---------------------------
900cc--------------------------- *Drivers must weigh 180lbs. with
1000cc-------------------------- protective gear or add ballast.
* Weight rules not in effect at this time. Will use ISR guidelines for weights.

* Snowmobiles must have OEM STOCK for the model: frame, brakes, engine, pipes and muffler, carbs /
throttlebodies, clutches, gas tank, hood, seat, console, cooling system, front and rear suspension.
* Stock OEM airbox, no modifications or may substitute with commercially available air filters made using
paper or fabric elements.
* Suspension may be limited to 2" remaining travel front and rear. Any stock length ski allowed. Any
replacement springs allowed. Suspension must be used as furnished by manufacturer.
* Marginal snow wheels may be added or removed. Slides may be removed.
* Wiper / speed tracks allowed. Tracks must be OEM width and length for model. Any race stud allowed,
max. height of .750 inches over track lug. Shaved tracks allowed, must be approved by Tech.
* Carb tuning parts allowed. EFI fuel restrictors or control boxes allowed, not tunable by driver during race.
* Any stock type clutch tuning parts allowed.
* External cool-down allowed.
* All snowmobiles in this class and up, require a working tether switch with cord, attached to driver whenever
sled is running.

MSDRA Improved Stock

440cc (max) +1%--------------------
500cc (max) +1% -------------------*650lbs. All
600cc +1% ---------------------------*700lbs. (triple) 625lbs. (twin)
700cc +1% ---------------------------*750lbs. (triple) 675lbs. (twin)
800cc +1% ---------------------------*775lbs. (triple) 685lbs. (twin)
900cc +1% ---------------------------*775lbs. (triple) 685lbs. (twin)
1000cc +5% --------------------------*775lbs. (triple) 685lbs. (twin)
Open (no cc limit)------------------- *775lbs. (triple) 685lbs. (twin)
Minimum combined weight is for sled and driver
* Weight rules not in effect at this time.

* Everything allowed in MSDRA Stock is allowed in Improved Stock.
* ISR guidelines in effect unless noted here.
* Track width may be changed as long as suspension or chassis not modified to allow change. Suspension
must mount using original mounting plates.
* Engine, cylinders, heads, crank-case, carbs - Must be OEM. Internal modifications are only allowed.
* Any functionally silenced exhaust allowed.
* Any primary and secondary clutch allowed.
* Jackshaft and driveshaft may be replaced - Must be like material.
* Drive sprockets may be replaced - rear idler wheel may be replaced.
* Lightweight hood may be used, must be stock appearing.
* Clutch guard must cover top and come down half-way on side of clutches, rear tunnel enclosure per ISR
spec required.
* 800cc and 1000cc - any available long track kit may be added to OEM suspension. Rail extension must be
welded. (No aftermarket suspensions)
* 1000cc / Open - any aftermarket cylinders and heads allowed. Crankshaft or stroke may be changed. Any
carb allowed.
* Open: no cc limit. Factory OEM power adder allowed (4-stroke turbo) but must run on pump gas not race
fuel. Aftermarket power adders (turbo, NOS, superchargers) not allowed. Meth injection allowed.

MSDRA Pro-Stock

500cc (max) +2% -------------------*550lbs. All
600cc +2% ---------------------------*625lbs. (triple) 550lbs. (twin)
700cc +2% ---------------------------*625lbs. (triple) 550lbs. (twin)
800cc +2% ---------------------------*625lbs. (triple) 550lbs. (twin)
1000cc +2% --------------------------*625lbs. (triple) 550lbs. (twin)
Minimum combined weight is for sled and driver
* Weight rules not in effect at this time.

* Any alterations allowed in MSDRA Stock and Improved Stock is also allowed in MSDRA Pro- Stock. Must
be stock appearing.
* Triple engine in twin chassis allowed, must be same brand.
* ISR clutch guards and tunnel enclosures required.
* Ski suspension: material substitution allowed. All components must be mounted in the OEM location on the
chassis.
* Rear suspension: any track suspension allowed. Material substitution allowed. 144 inch suspension max.
* Ski and track suspension must have 1" travel for ice racing.
* Any commercially available rubber track allowed.
* Framed body material substitution allowed. Tubular front ends, "bulk heads" are not allowed.
* Any carb, one venturi per cylinder.
* Any ignition allowed. Launch control allowed.
* Brakes on driveshaft recommended.
* 1000cc ONLY may use aftermarket cylinders and heads. Reed angle may be changed. Top of reed
housing may be modified. Must use OEM crankcase, same brand as snowmobile.

MSDRA Open Mod

600cc +2% --------------------------- 250lbs.
700cc +2% --------------------------- Minimum weight is for sled only.
800cc +2% ---------------------------
1000cc +5% --------------------------
* Weight rules not in effect at this time.

* Any alteration allowed in Pro-Stock is allowed in Open Mod.
* Turbochargers are allowed in 1000cc, on 4 cycle engines only.
* Superchargers and N.O.S. not allowed.
* Lay-down sleds allowed. Must have fully enclosed clutch guards.
* All sleds must meet all safety requirements.
* Brakes on driveshaft recommended.
* Launch controls allowed.

MSDRA Outlaw

This class is for the "Lakeracer" or larger cc powered lay-down type sleds. Specialty built sleds allowed but
must meet all safety requirements.

* Turbos, super-chargers, and N.O.S. allowed.
* Pro-Stock safety rules apply for "Lakeracer" type sleds.
* Open mod safety rules apply for lay-down sleds.
* No cc limit on engines.
* Turbo's allowed to use straight pipe after turbine.
* No weight rule, sled must be deemed safe by Tech.
* Any chassis, must have a snowmobile engine.
* Snowmobile must use snowmobile type clutches.
* Must be track driven. Any rubber track, any stud allowed.
* No stud height rule in effect.
* Launch controls allowed.

MSDRA Super Stock

600cc------------
800cc------------
1000cc-----------

* Any alteration allowed for MSDRA Stock class is also allowed in Super Stock.
* Aftermarket silencer cans, y-pipes, and reeds are allowed
* Stock pipe may be modified.
* Must use stock cylinders and heads.
* No Carb boring allowed.
* No throttlebody modification or exchange allowed.
* Suspension must remain stock.
* No light weight parts allowed.