Seth's snowbike rebuild and log.

[Uncle si]

I bought a Mountain Horse kit and a 2012 KX450f 13 months ago. I ride a lot and I've broken or worn out a lot of bits, so I thought I'd try to put everything in one spot to share my experience and try to track all the breakage.

I'll try to do this chronologically, which will mean a bit of going back to edit as my fallible memory coughs up more detail.

I started with test rides: Travis and Lee took me out and I rode mostly on a KX500 with a snowhawk ski on April cascade concrete. The machine was very impressive. I watched Lee scoot up a 35 degree slope and into the steeper tight trees above. My ability to keep it in the powerband was less impressive. I rode a KX450f with Allen on spring snow in Idaho and found the wide powerband a lot easier for a motorcycle neophyte. At that time I had perhaps 50 hours on all types of motorcycles. (I'm pretty damned good on a snowmobile. Not great, but I can get a two-ski about anywhere I see other people get them. I'm modest, too. )

I rode my Kx450f / Mountain Horse with the 6" Simmons ski from May to July 2012 and from October to June last season. I've ridden approximately 80 days on snow and twice with wheels on.

I love this machine, and cannot go back to a snowmobile. Allen and company have done an amazing job. Travis (Backcountry Snow Bikes) has been really helpful, too. I've broken a lot of things, but I ride hard and I ride a lot.

Here's the quick list of mods/upgrades/wear/damage/etc, some of which I've mentioned in other people's threads:

Mods:
Handguards
Canadian Gas can on tunnel
Skinz tunnel bag for tools and snow bungie
Cyclops Headlight
Snowhawk ski
10" Simmons ski modified for the bike
Radiator guards
Aluminum skid plate
2.7gallon clear fuel tank
Grease-able bearings


Broken/Failed:
Inner clutch cover gasket failure
6" Ski is, simply put, the end of the world.
Wore out rear swingarm sliders. I must get photos of this, and will grease the new ones for each ride.
Clutch cable, at the hand lever
Sheared lower strut bolt
Broke a primary chain master link after 3 rides?????
Jack shaft bolts loose repeatedly
Worn primary gear - see broken master link?
Headlight ground not installed properly - by me!
Broke my bolt-on ski keels
Broke off radiator shrouds - I rode through a Christmas tree farm
Broke handguards through over-use.
All for valves out of spec on the loose side. I was expecting them to be tight.

I just put the wheels on for the summer, and plan to do a complete tear down of the kit to find every bit of wear and damage I can. There's probably something else broken.....

12-24-2013: On ride 13 for this season I joined the broken sub-frame club. The 500 is running great. Track spin is always on tap, and I want more track.

Feb 2014: The 500 s**t the bed. Tear down time, and back to the KX450F.

2-15-2014: I've been out twice on my 146x2.5" track under a KX450F on heavy Washington powder.

My initial impression is that it is amazing. It will tractor up silly steep slopes and holds very well. The ski tends to wash out first when pushed hard. The turning radius may have increased a bit -I left the skid setup stock, and I think a little more transfer under throttle may be helpful.

Feel free to fire away with suggestions or questions!

 

[Uncle si]

The usual stuck mode is ski in the air:

Spring on Baker

Skis: Modified 10" Simmons, snowhawk, 6"simmons

Here's my modified 10" Simmons. Had some problems with warm snow packing in the tunnels.

 

[Uncle si]

Edits:

I've ridden approximately 80 days on snow and twice with wheels on.

I'm worried that loose valves are the result of valve seat wear or worse.

 

[jskattum606]

That's weird there loose. The only way they should mechanically be able yo go is tight. How much we talking here?

 

[Uncle si]

That's weird there loose. The only way they should mechanically be able yo go is tight. How much we talking here?

The valves are between .27 and .30mm

 

[snowmoherb]

Nice write up, but... Did you get a truck yet

Sent from my DROID RAZR HD using Tapatalk 2

 

[Uncle si]

Easy there Herb, summer just started! I still have the old truck, just put wheels on the bike. I'm working on it..........

Where is the snow?


Edit 9/9/2013. I got the truck problem sorted!

 

[1dn5up]

still snow on the actual volcano, its it even possable to ride on it? or no way to get there?

 

[Uncle si]

still snow on the actual volcano, its it even possable to ride on it? or no way to get there?

There is not a lot of accessible quality snow around here now, and I've got a lot to do just to be ready for next winter.

 

[snowmoherb]

Easy there Herb, summer just started! I still have the old truck, just put wheels on the bike. I'm working on it..........

Where is the snow?

Lol, you're the one that told me to kick you in the nuts if you didn't have one by next season . I just don't want to have to do that to a friend, so I'm trying to give you a friendly reminder

Have you been doing much riding on the wheels?

Sent from my DROID RAZR HD using Tapatalk 2

 

[Uncle si]

Lol, you're the one that told me to kick you in the nuts if you didn't have one by next season .

Have you been doing much riding on the wheels?

No one wants the old truck. I may put single rear wheels on it and run it until it rusts apart

I've been out on the wheels and the bike is pretty fun! Half the guys I rode with had trials tires and my first gear is pretty tall. Faster=easier anyway, right?

 

[Uncle si]

Updates: valve buckets are worn, shimmed valves to within spec for more dirtmobiling.

I replaced the diesel dually and leSubaru with a Tundra.

I've been haunting craigslist searching for a Kx500 and Washington is pretty sparse. I think I'll drive to SoCal/Nevada and buy one or two. I have been giddy about the idea of more power - and the snow we'll get next month.

Work has been silly bordering on stupid. I need to get that sorted.

 

[Uncle si]

I got a Kx500 and ordered all the bits I know I'll need.

Still researching some questions:
Dial a carb or smart carb? 80% of my riding is between 4k and 5k.
What pipe guard to prevent flattening and how much insulation do I want? I hit a lot of trees and stumps with the pegs, so this pipe needs protection.
How to dampen the vibration for my hands?

It looks like I can start riding this week. The 450 is ready if I hit a stumbling block with the 500.

 

[backcountrysnowbikes]

Your going riding this weekend? Where

Wife doesnt want a 163 so ill just put your name on one of my kits in stock. You will have to order a kx fit kit or i can either way let me know

Travis

 

[Uncle si]

I got a Kx500 .............

Tried out the 500 and it worked great but for the fubar clutch. The TS 10" ski is, as widely reported, very nice.

Now I could use a bunch of snow.

 

[Uncle si]

The 500 works well. It could be our dust-on-crust conditions, but I am experiencing a huge amount of track spin.

I am daydreaming about trimming and rounding off a 144" x 2.5" track. I need to try the 121 in decent snow before I go too crazy.

I was expecting trouble in cold temps, yet the beast ran well at -5!

 

[Uncle si]

On ride 13 for this season I joined the broken sub-frame club.

The 500 is running great. Track spin is always on tap, and I want more track.

 

[Uncle si]

I've been out twice on my 146x2.5" track under a KX450F on heavy Washington powder.

My initial impression is that it is amazing. It will tractor up silly steep slopes and holds very well. The ski tends to wash out first when pushed hard. The turning radius may have increased a bit -I left the skid setup stock, and I think a little more transfer under throttle may be helpful.

I started with a 2011-2012 kit with a 121x1.75" track.

http://www.snowest.com/forum/showthread.php?p=3377077

 

[Uncle si]

500 carb changes today:

Needle n82m. From 2nd position to third
Main 168 to 170
Air screw 1.5 turns out to 1.
Slow jet 58

We'll see how that goes.

 

[Uncle si]

I finally put a temperature sticker on the 500 today. She gets to 170 in a couple of minutes, then shoots above 200.