2015 YAMAHA MOUNTAIN MAX 600 TRIPLE

This 600 TRIPLE is *dynoed by  Rich Daly to have very close to 100 HP . This Mountain Max is published to weight about 511 Lbs. The reverse kit we added would add a couple Lbs. The original track is a 141 x 15 with an advertised 2" lug, This track was really good providing unreal traction IE: my trip leading down thru the trees into the valley 15-05. We have changed this track to a 141"x 1.1".  This allows us to use a larger diameter driver and  out in the prairies she will not hit a brick wall for top end speed. A medium lug track this responsive 100 HP mill will get better mileage yet, and will still make a great trail breaker thru the tight NISBET FOREST trails.

101 HP mill make it a great trail breaker thru the tight NISBET FOREST trails. But that is only half of the story...rarely is economy discussed, expect bragging rights at every fuel stop!
Economy...we rarely discuss fuel mileage at SNOCRUISE in the Saskatchewan prairies because we ride such large variety of cross-country snow conditions. We are more concerned with the relative location of Small towns with fuel service in our riding area. But under archives we tabulate fuel usage for fun at most stops. Look for an "F" added to the rides "Link" on our "Archives page. Fuel mileage is usually best gauged on consistent "groomed trail riding" conditions. *Source November  1998 American SNOWMOBILER magazine.

 20-13VF,  20-12VF, 20-10VF,  20-02F,  20-01F,
16-07 VF,  16-06,  16-02 F,
15-05 F,  15-03 F,  15-02

1) We Fire the MM Up! and Switch Front Ends

2)  CHAINCASE UPGRADE to REVERSE and REPAIR

3)  HANDLE BAR RISER, 45 DEGREE ENDS A SKID PLATE and ICE SCRATCHERS

4) FIRST RIDE...HOLY HANNA!

5) 15-03 Duck Lake is surrounded by the Bulls!

6) 15-05 The days mileage speaks for it's self!

7) 16-02 F Once again the days mileage speaks
for it's self!

8) 16-07VF Flat out all day...this long track was in the number 2 spot every time I turned around to check!

9) Track Change, here we go with scheduled lower drive bearing maintenance.

10) A little tweak in the front suspension with back to back rides to get the feel and feedback.

1) After purchase we Fire the MM Up!
and Switch Front Ends

Before we start with our modifications lets go thru the carbs and get the sled up and running properly.

There is evidence of old fuel and ample supply of gunk in the bowels.

The carbs jets are pretty dirty.

She sparks right up and sounds excellent! She had been in storage before our purchase for years.

Side by side with the donor parts sled where we salvaged the complete front suspension...

 2)  CHAINCASE UPGRADE
to REVERSE and REPAIR

Lets pull the cover off and have a look	Spotless this assembly is in pristine condition at 2700 Km, I plan to add a new chain just because.	With the reverse (pun intended) installation nicely under way, every thing is really nice and clean, the engagement side of this reverse idler looks good.	Some evidence show that they just road the sled that way, forward while the gear box selector was in the reverse position and the gear box buzzing loudly!
But it seems that the donor sled had several deficiencies!  We found that once engaged into reverse the linkage was so sloppy because of the replacement of some non-conforming bolts the sled refused to fully engage by just buzz loudly.	This is evidence that the gear box buzzing loudly whiles selected reverse actually was not fully engaged into reverse was then put back into forward with the whole assembly freewheeling yikes! Forward engagement cogs are hammered on the edge.	This is the gears alignment when the reverse is not actuated.	This is the clearance between forward and the application of reverse. Any worn parts or linkage would allow the gears to slip out of reverse under pressure.
The shift forks were worn half away from the  constant pressure of been left in reverse for a long time.  The We had the shift forks welded back up then roughly ground round again.	This shows the reverser engaged by hand and more fully engaged than what the forks would move the cluster over to disengage the forward engagement cogs and engage the reverse idlers.	This is the reverse process. 1. Power enters via secondary clutch to jackshaft to drive the drive sprocket. 2.The drive chain rotates in a clock wise direction following the tensioner and around the bottom sprocket. 3. The "HAND" or shift fork engages the shift cluster disengaging its forward engagement cogs, and while engaging the reverser idler. 4. The reverser idler engaged and running "COUNTER CLOCKWISE"  5.The gear cluster in reverse or counter clockwise. 6.Which is now driving the track drive shaft by a set of splines which are partly visible between the cluster and bottom sprocket.	Walla! A reverse gear box ready for the shift fork cover and oil etc!

 3)  HANDLE BAR RISER, 45 DEGREE ENDS A SKID PLATE and ICE SCRATCHERS

This raising the handle bars a couple inches is one small miracle to rider comfort on a domestically designed snowmobile.	Adding a couple 45 degree hooks is big, and you don't notice how nice they are until they are missing.	The skid plate is big here when you spend a lot of time in the Nisbet backcountry.	Toss in a Bow saw to compliment the chain saw on our next outing and we are just about good to go!
Our ice scratcher install begins with	locating an area on the slide rail	where the ice scratcher can be mounted	in such a way that when not in use the scratcher has a resting place that keeps it our of the rest of the suspensions moving parts.
It looks like removing a pair of forward idler wheels and turning the mount around will free up some needed space along the slide rail.	If we mount this right the scratcher will rest on the slide rail when not in use.	So we carefully model and measure so a hole can be drilled for mounting.	The hole has to be mounted low enough so the tail end of the spring actually will place some reasonable pressure when engaged for groomed trail riding.
If the mounting hole is in the right place we will not need a second hole for the spring tail.	Yup the hole once we verify this will work on this side we will duplicate the hole on the other side.	Mounted with some decent spring pressure.	Hanging on its own we have the spring pressing downward considerable, catch some air like this and all should be good and relative to the track direction.
With the spring in its at rest not in use position we have taken advantage of a recess in the slide rail near the rear ahead of the rear scissor bumper stop.	Nice		Notice We had flipped the mounts around and seeing the rear idlers like that thought yea all is well...
...not so the shock and assembly drops down in this centre area at he front.	A photo of the scratchers disengaged.	Replacement hardware instead of the mid idler brackets etc.	A photo of the suspension from a rearward vantage point.

4) FIRST RIDE...HOLY HANNA!
I have no idea what was really stopping the Mountain Max from revving 10,000RPM!  Any throttle opening over 1/2 was seeing the little triple wound to 9,500RPM! Acceleration was ho hum, I never even tried for any reverence to really see actual top end...I saw 100 to 110kph on a couple occasions when I held the flipper down on the lake for a excruciating few extra seconds! And handling...she just wanted to track kind of straight. The sled resisted turning, as if that was the last thing on its agenda, hell lets just go straight down the middle of the lake with absolutely no desire to duck in and out of the little coves and bays full of powder. I could just see it now, put "Joe average" on such a handling sled and a snowmobile ride would be just that, a snowmobile ride, no fun, no desire, to toss her around or lean her over and try carve some banks.  Combine the extreme high RPM and the crappy handling I can only imagine that all you would be thinking is "God I wish this ride was over" or "God why did I ever buy a snowmobile!"

I can barely believe the original owner put 2750 KM's on her! (1705miles) Prior to riding it I actually wondered how you could own such a nice looking and sounding piece of equipment for 14 going on 15 years and have only 1700 milers on it, as a group there is a few of us that have put on over 300 miles in a day and that was riding cross-country meadows, bush land and fields!

LOTS OF ADJUSTING TO DO LET THE GAMES BEGIN!

First item on the agenda was replace the primary clutch spring with one known to work well. The original clutch spring was a YWY We have an OEM YGY in our 600 Triple Deluxe.	I see on Totally Yamaha's site and thru parts look up sites that the 600 SX another 121 short track also uses this spring. We like the way our 600 Deluxe works so that is the direction taken.	A look at the weights and we see this is all stock Mountain Max, wow this thing is clutched for a different planet!	In the above photo I put a caliper on the rollers. There are several different diameters and we just want to verify which ones are in here.
We put a fish scale on the secondary.	I grab a collection of secondarys to take with us on the next ride.
When this sled was acquired a close examination revealed a track that was "hamstring" tight. Looking closely it we see many small cracks in the exterior layer of rubber. Worrisome, but so far so good 300+ Kms later and nothing has let go!	The front straps were "all the way out" which allowed the suspension to Torque the whole chassis including the skis up into the air under any form of acceleration or normal application of power.	When Hanging in the air, the front slide rails just make contact with the cement floor.	The difference mathematically is the front straps pulled all the way in, and YES pulled all the way in, so you can attempt to feel the difference in the most defined way, for good or for bad.
How is the average person supposed to feel or realize a very minute change. The rails all the way out at 9 1/4", the difference to 7 7/8" is a change of 1 3/8"	Every outing costs a lot of money and there is no sense making minute little changes to a sled just to pound hundreds of dollars of fuel and depreciation into the sled for nothing.	The front straps now "all the way in" which restricts  the suspension to Torque the whole chassis including the skis up into the air under any form of acceleration or normal application of power.	With more ski pressure the sled should drive completely different.

5) 15-03 Duck Lake is surrounded by the Bulls!. Acceleration was much better! You could actually sense that the sled was accelerating when you put the flipper down!. And handling...There has been a drastic change in the sleds handling. Now the sled is fun to ride you can turn and maneuver in and out of the snow, NIGHT & DAY! Would  "Joe average" know the difference? Maybe not, not unless he had back to back rides on the sled.

Was the sled still over revving ? Yes I would see around 9,200 and holding, we are getting closer! I am still not inclined to "hold her to the pin for any length of time". Although the weights in the primary clutch were the same, the rivets added by Yamaha were different. The outside rivets ( two in each weight) were lighter in the MM version vs. the SX or Deluxe version of the sled. Next mod change the weight of the weights by swapping in heavy outside rivets.

7) 16-02 F Once again the days mileage speaks
for it's self!
A little flash to 9,000 off an aggressive start then as soon as you were rolling she would back up and the RPM would settle down to 8,500! Perfect for a day of riding in the Nisbet! And sounds nice cruising at 6-7,000RPM the triple sounds fantastic...when will the OEMs build a E.O.G.&F. (easy on gas & fumes) triple? When they build one people will flock back to the sport in big numbers just for the sound!
 On this day 16-02 she carried the chain saw and was our work horse.

Loaded up with the chainsaw and all the fixings this sled now accelerates really well! Enough to get you in trouble in a big hurry if you are not paying attention!

8) 16-07VF Flat out all day...this long track was in the number 2 spot every time I turned around to check!
You can see the monster rooster tail of snow flying up behind this sled in the videos. Gonna change that. Across the prairie and around on the small lake, but it was evident she was up against a brick wall for top end.

9) Track Change, here we go with scheduled lower drive bearing maintenance.  
In the off season...#9 we have a lower drive bearing change across the board and while we are in there...install a 1.1" track for more top end. There is still great floatation!

Getting started this is track change is going to be merged with fleet maintenance.		There is no telling how long this stick was trapped up in the tunnel.
The 1.1" we are installing is going to carry a lot less snow. This should improve cruising speed in the prairies.	There is a big difference in driver diameter. Larger diameter driver=less rolling resistance.	I used some sockets to space the drivers I had to push onto a spare drive shaft.	The Yamaha uses a "o" ringed bushing to seal the bearing from the snow. The lower chaincase bearing is fine. It just needs grease.
This was this seasons scheduled maintenance on all our sleds, repacking all the speedo side drive bearings. This one was seized on and a real bear to remove!!	Pound all the seals nice and flat with a mallet. The seals usually get a little bent pulling them out. I did not use the "ball peen" happening to be on the bench in this picture!	The chaincase lower bearing is repacked.	Here we are with some correctly sized track clips. I was pretty surprised at how many track clips this used, otherwise good track needed.

10) A little tweaking, I make a minor sounding adjustment and get big results. That's what it is all about from a motor head perspective.  
Set up for carrying the chain saw I strap on the axe and we use this Max for our bush whacking and exploration. The 1.1 is clearly the way to go, Maximus acceleration, speed, just a couple adjectives to throw out there.

Now for some front end adjustments not that evident in the first couple rides of the winter, but now that we have really good snow......I notice something is amiss, I made the same adjustment to our Blue Max... with the same great results.

20-12VF As assembled as our project sled in 2015 I felt I could make the sled feel more positive and playful just by cranking the front end up, a couple inches.

20-13VF At a glance the parallelism between the trailing arm to the tunnel is obvious to the motor heads eye....The 2 inch (or so) crank up on the variable rate front springs has made a big difference in stability and steering control, more steer...she steers....and you ride 'er with more a more positive confidence. It doesn't hurt that these sleds look a bit better with the trailing arm and tunnel alignment.