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141″ Track Kit

141″ Track Kit
Yamaha Mountain Max 136″ to 141″ Update Kit

Don’t sell your sled !!! Update it with our 141″ x 2″ year 2000-update kit. Take your 97, 98, 99 Yamaha Mountain Max 600 or 700 and improve on a good thing. We have developed a kit that lowers the approach angle of the track from 31 degrees to a phenomenal 17 degrees by moving the W-arm and entire slide frame back. These modifications with the addition of the new 141″ x 2″ track will make your Mountain Max get on top of the powder faster and stay on top at slower speeds.Warning: Drive axles break in 1997-1999 Mountain Max’s. A new upgraded hardened shaft available for $195.00.


View from Above

It also improves climbing ability in deep powder conditions by getting you on top of the snow instead of pushing it up hill! The repositioning of the W-arm and the slide frame makes the front limiting straps much easier to get to so you can easily adjust your ski pressure for improved steering. Plus it changes the angle of the control rods from 30 degrees to 38 degrees which gives you much better weight transfer over a longer period of time. The improvements with the kit also include a tapered tunnel extension for increased vertical clearance by 4″ which reduces snow drag. The bumper is easily accessible in the unlikely event you should get stuck.


On the Hoist


Original 31 Degree Angle


New Track angle of 17 Degrees

2000 Update 141 x 2″ kit Parts Inventory
2 Tunnel template and reinforcement plates
24 3/16″ x .25″ Steel rivets (black)
15 3/16″ x .25″ Steel rivets (black)
4 Small square reinforcement mounting plates
1 10mm bolt & nut
2 Rear mounting plates
2 Long steel large head rivets
6 Lock nuts
1 Tapered tunnel extension
1 Cooler template
2 9.5″ long x .75″ ID hose
4 Long 3/16″ large head rivets (flap)
2 bumper support plates
2 8×1.25 Flange nuts
2 8×1.25 Bolts
2 Upper W-arm bushings
4 Lower W-arm bushings
1 W-arm template
2 3/8″ Flat washers


The Parts Kit

Optional Items
Extrovert-Anti-Ratchet Sprocket $195.00 for Two
HiperFax $210.00
Cargo rack $70.00
Works Performance Gas Shocks (2 shocks) $590.00
141″ x 2″ Camoplast track (with kit only) TBD *

*Prices may change without notice. Tracks are ordered Pre-season with Discounts, we pass discounts on to you. After preseason Tracks are gone we pay more for each track. The price must go up.

This kit is designed to increase the performance of the snowmobile, use extreme CAUTION We will not be liable for damage, personal injury or death on any modifications performed. 


1. Drain oil from chain case. (12mm inside tunnel)

2. Loosen rear axle nut then track adjusters.

3. Remove slide rail suspension. CAUTION : Use a wood block to support main shock while unbolting or you bend the tunnel.

4. Remove driven clutch and speedometer gear assembly. NOTE : bearing has 2 allen set screws inside tunnel that need to be loosened to remove.

5. Remove chain case cover. Remove gears & chain. Check gear ratio (2:1 is optimum for this kit).NOTE Use brakes to loosen gear nut, remember spacer locations for re-installation.

WARNING 6. Remove chain case from tunnel. NOTE : Brake unit will stay with chain case no need to remove brake lines. WARNING : Do not loose key for brake rotor or brake will not work causing damage to snowmobile or personal injury.

7. Remove old track and driveshaft from tunnel. This application requires 8 tooth drivers to clear front cooler and tunnel. They will need to be pressed on, trued on a lathe for alignment of track with slide frame and maximum performance without vibration. NOTE : The drivers have arrows that must be aligned to the same position on the shaft.(On the tips of the lugs) Machine outer lugs off if application requires it.
NOTE : extroverted anti-ratchet drivers highly recommended.

Center to Center

Trueface     not needed on no slip drivers

WARNING : When drilling, use extreme CAUTION not to drill into the coolers.

After drilling always remove burs to insure flush fit. Due to manufacturing tolerances all holes may not align if necessary re-drill or use a small round file to align. NOTE : Insert rivets in all holes in each section before crimping. Use small headed BLACK rivets on all exposed sections of kit.


1. Drill out rivets on rear shock forward mounting brackets and remove, the factory plates are not re-used. (see photo 1)

2. Mount left and right tunnel reinforcement mounting templates inside tunnel with 10mm alignment bolts supplied in kit which may be removed after installation. (see photo 2)

3. Drill front 3/16 rivet holes from inside tunnel toward outside at approximately 1 3/4″from front edge of reinforcement mounting templates. Use existing factory holes in tunnel to drill 3/16 holes from outside of tunnel toward inside through rear of reinforcement mounting templates and rivet. Clean all burs from holes to ensure flush fit. (see photo 3)

4. Drill 25/64 front and rear slide frame mounting holes in tunnel from inside tunnel toward outside using existing holes in reinforcement mounting templates. (see photo 4)

5. Use 25/64 hole and a bolt to align outer tunnel reinforcement mounting templates (small square plate with 5 holes). Drill the 3/16 rivet holes from outside of tunnel toward inside and rivet. Clean all burs from holes to ensure flush fit. (see photo 3)


1. Remove left and right tunnel reflectors and drill the holes to 21/64. (see photo 3&5)

2. Remove 3 rivets from left and right side of tunnel where rear slide frame mounting plates will be attached. (see photo 3&5)

3. Install new rear slide frame mounting plates inside tunnel with cup out using 21/64 hole drilled in tunnel reflector mounting position. Use one large head rivet to align then tighten nut. (see photo 3&5)

4. Drill 21/64 lower mounting holes and fasten. Use LOCTITE(r) and factory torque values on all bolts and nuts. (see photo 3&5)


1. Drain coolant. This will be messy have damp towels ready and don’t forget to remove radiator cap to release the vacuum. Remove plastic bumper cover, hoses, bumper and flap.

2. Drill out rivets that hold rear cooler section to tunnel. Then drill out rivets that hold cooler to that section. WARNING : When drilling, use extreme CAUTION not to drill into the cooler.

3. Cut and weld cooler fittings to fit flush to top of tunnel. (see photo 6&7) Template included in kit. SRX cooler cut to application. We use 1″ Copper tubing and two 90 degree fittings to build the Crossover Tube.


1. Slide new tunnel extension into tunnel flush to the reinforcement plates then clamp in place. Drill holes using existing tunnel holes as a template. Clean all burs from holes to ensure flush fit and rivet into place. (see photo 8)

2. Position and center cooler in tunnel extension. Drill mounting holes in tunnel extension and rivet cooler using three rivets per mounting tab. (see photo 7) Clean all burs from holes to ensure flush fit.

3. Install new hoses using factory clamps. Remove bleeder in cooler and fill system Re-install bleeder. Install flap using four large headed rivets.

4. Remove front lower rivet and drill to 21/64 this is lower mounting hole for bumper support plate. (see photo 9) Install bumper and support plates using factory bolts and two bolts for lower support mount in kit. Use LOCTITE(r) and factory torque values on all bolts and nuts.

5. Trim to fit and install factory hose covers. (see photo 10) CAUTION : you only get one shot so trim carefully.


1. Remove w-arm from slide rails and both sets of bogie wheels then clean up rails where they were mounted.

2. Install rail-drilling template using front and rear bolts to hold in place. Mark and drill holes 21/64 and 25/64 respectively using center punch to start hole. (see photo 11)

3. Install and lube new bushings in upper and lower w-arm pivot points. (6 in kit)

4. Install the offset bogie mount in front hole of lower pivot and drill 21/64 hole for lower bolt. (see photo 12)

5. Install aluminum cross shaft in front holes of slide rails. You must add a 3/8 washer to each end between shaft and rail to insure proper alignment. (see photo 13)

The YAMAHA 8DF BSKIT-00 W-ARM bump stop kit is highly recommended.


1. Move new track under tunnel (check rotating direction of track). NOTE : Some applications require the rivets on the inside tunnel braces to be ground shorter to keep from rubbing lugs of the track.

2. Install driveshaft into chain case side of tunnel first then rotate to speedometer side of tunnel. : Align driver lugs to fit inside track drive lugs so it does not bind while installing the driveshaft.

3. Lube inner chain case seal. CAUTION : Do not damage seal while installing chain case over shaft.

4. Make sure key for brake is properly installed. WARNING : The brake will not work if key is not installed properly causing damage to snowmobile or personal injury

5. Install chain case with proper gearing (2:1). NOTE : Return spacers in original positions, use brake to tighten nut.

6. Return chain tensioner to factory setting and tighten lock nut.

7. Install chain case cover. CAUTION : Lube chain case cover seal and be careful it’s fully seated so it doesn’t get pinched when tightening cover.

8. Install drain plug. WARNING : Not installing drain plug and filling chain case to factory specifications will cause severe damage to chain, sprockets and case. 250cc of gear oil.

9. Install speedometer gear assembly, check bearing and cable for proper lubrication. NOTE : Remember to LOCTITE(r) and set the 2 allen screws that lock the bearing.

10. Move slide frame into position inside track. CAUTION : There are many sharp edges inside slide fame that will remove skin from knuckles.

11. WARNING : Make sure snowmobile is supported so that it won’t fall and crush you while you’re inside the slide frame the shocks are under extreme pressure. TIP: Use a block of wood to hold up main shock, use 6″ block of wood under rear of track, this will help to align front mounting bolt holes, then put that same block under front of track to install rear mounting holes. A small ratchet tie down is a must to hold and move slide frame inside tunnel.

12. Use LOCTITE(r) and factory torque values on all slide frame mounting bolts and nuts.

13. Give the snowmobile a good once over. CHECK YOUR WORK. even the best wrenches can miss something that’s why they double check everything.

14. WARNING : Make sure snowmobile is safely supported and everything is clear while track is in motion. Align track so that hifax run in center of track clips TIP: With YAMAHA adjusters the adjuster you tighten is the direction track will move towards.


This kit was designed to be installed by a person with mechanical ability and a good working knowledge of snowmobiles.
Installation time 4 hrs.

Complete Kit start at $270.00 plus price of track.

updated 7/20/2016