Home Made Snowdog

[jackfrost]

Good day all! I am in the beginning stage of building a "snow dog" I have stripped and cut down a early 90's Arctic cat 440 and I have left the existing jack shaft and gears on it. I have also removed the back springs and secured the rear suspension down so the tunnel is now level. I am looking to put the predator 420cc engine with a 40 series torque converter on it.
The question I have is: does anyone have any advice as to what size gear I would need on the jack shaft and do you have to have the jack shaft machined for a key way or is there an option to use a gear with set screws?
Thanks!
My progress so far......

[RoeBoat]

Have you checked YouTube,  lots of info on there?   Would love to see pictures of your build!

[wolffpack08]

I used a 71 snow jet that was free and in really tough shape.   I used a predator 212 and a cheap  30 series torque converter along with the existing chain case on the sled.  I'd have to count but I used either a 30 or 20 tooth sprocket.  Top speed is 20 mph which is more then enough

[jackfrost]

Have you checked YouTube,  lots of info on there?   Would love to see pictures of your build!

Thanks for the reply and yes I have watched many videos on youtube and it certainly was helpful! I will upload pics as I progress.

[jackfrost]

I used a 71 snow jet that was free and in really tough shape.   I used a predator 212 and a cheap  30 series torque converter along with the existing chain case on the sled.  I'd have to count but I used either a 30 or 20 tooth sprocket.  Top speed is 20 mph which is more then enough

Awesome and thanks!  was going to try the 212 engine but was unsure it had the power needed? But it sounds like it works for you and 20mph is plenty of speed. If possible could you send pics or info on how you put the sprocket on the jacksahft?
Thanks and I will post pics as move along with this project.

[appleman]

[appleman]

Here is the one I built. I used a 6.5 predator motor and a arctic cat chassis

[RoeBoat]

Nice looking compact unit.  Would like to build something but I think I'm going to go the "magic carpet" route so I can ride on the unit itself.

[flit]

  Looks a little bit small. Did you cut the tracks how was the performanc

[wolffpack08]

I used a 20 tooth sprocket, pulled the secondary clutch off of the chain case shaft and put the sprocket there.   

[jackfrost]

Well more progress on the track machine! Decided to go with a predator 212 and a 30 series torque converter. Waiting on the jack shaft to come back from machine shop and then I will install gear, chain and then mount motor...

[DR.SPECKLER]

Nice.ive got engines and torque converters already but need a junk donor sled.anyways was wondering why you didnt use the stock jackshaft with the original chaincase and brake setup from the snowmobile ?im going to just remove the original torque converter and replace that with a gear that works with the original chaincase and gears and it will have the original brakes still.Just wondering.

[Garrett]

I used basically the same setup you did in my build. What I did was went on Mcmaster carr or amazon and started searching for the largest sprocket I could get to fit on the jack-shaft without hitting the tunnel with the chain on the sprocket. I started out with just using the setscrew to hold to the shaft and it spun on me so I took an angle grinder and added a slot for the key way, no issues since so good call on having it cut right away. I used the 212cc from HF and I am really wanting to upgrade to the 420cc for the extra power hold at full RPMs in deeper or wet snow/slush, and also to the electric start and charging circuit to run a headlight would be awesome!

One lookout I will recommend to all builds now is to build a hood. I didnt have one on last year and it sucked snow into the airbox when running in powdery snow. It didnt affect it until I stopped and the snow melted from the engine heat, then froze up the carb when the machine sat while I was fishing. Couldn't get it to go above idle and engage the torque convertor because of the ice in the carb. Ended up driving out with a trailer and loading up on the ice, which I REALLY didn't want to do with my new truck. but there was 2 ft of ice at that time. 

[jackfrost]

Nice.ive got engines and torque converters already but need a junk donor sled.anyways was wondering why you didnt use the stock jackshaft with the original chaincase and brake setup from the snowmobile ?im going to just remove the original torque converter and replace that with a gear that works with the original chaincase and gears and it will have the original brakes still.Just wondering.

I am actually using the existing jack shaft, brake and gears. I just had to remove it to have a key put in further down the shaft. I will have it back this weekend and install all back together with a new drive gear on it.

[jackfrost]

I used basically the same setup you did in my build. What I did was went on Mcmaster carr or amazon and started searching for the largest sprocket I could get to fit on the jack-shaft without hitting the tunnel with the chain on the sprocket. I started out with just using the setscrew to hold to the shaft and it spun on me so I took an angle grinder and added a slot for the key way, no issues since so good call on having it cut right away. I used the 212cc from HF and I am really wanting to upgrade to the 420cc for the extra power hold at full RPMs in deeper or wet snow/slush, and also to the electric start and charging circuit to run a headlight would be awesome!

One lookout I will recommend to all builds now is to build a hood. I didnt have one on last year and it sucked snow into the airbox when running in powdery snow. It didnt affect it until I stopped and the snow melted from the engine heat, then froze up the carb when the machine sat while I was fishing. Couldn't get it to go above idle and engage the torque convertor because of the ice in the carb. Ended up driving out with a trailer and loading up on the ice, which I REALLY didn't want to do with my new truck. but there was 2 ft of ice at that time.

Thanks for the info and my next one I think I am also going to go with a 420 cc and 40 series clutch. Also, I have some old road signs that I am going to build a hood out of.