1975 Scorpion 440 - replacing drive sprockets

[niobrarafun]

I have a few questions on drive sprockets for scorpions. I got my 440 running, but one of the drive sprockets is about gone. If I cannot find a good replacement drive sprocket, is there a way to make a common- easy to find drive sprocket work on my scorpion? How hard is it to replace the drive sprocket? I assume it will take a few hours to do, and is there any special tools needed to do the job. Thanks all for the help.

[mooreperformance]

Shouldn't be a problem finding a replacement drive sprocket.
A bigger job than you might think. Probably take you a couple of weekends if you have never done it before.
Sorry!
No special tools needed, only common sense and plenty of patience!
Buy the new bearings before you start the job and try to understand how they lock onto the shaft.
If you can't visualize how they lock onto the shaft you may have a problem doing the job.
The lock-on bearings work on a "cam" principle. They are a standard type bearing that have a locking feature that has been used on industrial equipment for about 100 years.
Not invented just for snowmobiles!
Ask any farm implement mechanic how they work...he will know. They are used on all kinds of farm equipment!
Good luck

[niobrarafun]

Thanks a ton for the information. Glad to hear that it is doable, even if it does take a lot of time. Any idea what the part number is for the bearings and how to get them? I am hoping to source the drive sprockets from a used sled. Is there any way to judge how good the sprockets are, other than visual inspection? I would hate to go to all this trouble only to have them fall apart on me. Again, really appreciate the help and I hope you don't mind if I ask a few more questions as I tear into this project!

[admin]

What model is your Scorpion? Whip? Stinger?

You might find a parts manual here,

www.vintagesnow.com/Scorpion.html

Probably not going to help much but you might search on the part number you need.

Once you tell us what model Scorpion you have, someone here can probably give you a model year range that has a compatible sprocket.

Is your top or bottom sprocket bad?

How many teeth does it have?

[scorp11]

First need to know the sled model for 1975. The Whips took a 3.29 drive pitch on an 1 1/8" shaft. The Super Stingers took a 2.52 drive pitch on a 1 inch drive shaft.

I can help you with the 2.52 sprockets, but the 3.29 drive sprockets I use are for the 77 and up whips and fit a 1" shaft.

In any case, get the black plastic reproduction sprockets. The old white ones will all crack / be already cracked, even if they are NOS.

[admin]

Ok then...just waking up over here. I see we are working on the drive sprockets (drivers) that actually touch the track!

Therefore, my questions about number of teeth and is it the top or bottom sprocket do not make much sense. I was thinking about chaincase sprockets driven by CHAIN.

[scorp11]

Dec 28, 2012 23:27:50 GMT -5 admin said:

Ok then...just waking up over here. I see we are working on the drive sprokets that actually touch the track!

Therefore, my questions about number of teeth and is it the top or bottom sprocket do not make much sense. I was thinking about chaincase sprockets driven by CHAIN.

I noticed that, and you made me go back and re-read the original post :-) Sometimes thats a good thing too !!

[crm]

I found bearings from an electrical motor and industral supply company, they are the 1 7/8" shaft bearing I used in my 75 Whip, the brand is an AMI Bearings Inc. #KH206-18. Hope this will help you out. Carl


UPDATE:

Dec 30, 2012 23:16:02 GMT -5 crm said:

Need to correct myself, I ment 1 1/8" not 1 7/8" shaft. Sorry about that. Carl

[admin]

Thanks CRM!

[crm]

Need to correct myself, I ment 1 1/8" not 1 7/8" shaft. Sorry about that. Carl

[scorplover]

Scorp11, do you sell the black reproduction 2.52 sprockets for a 75 super stinger? Thanks!

[scorp11]

Dec 31, 2012 21:56:45 GMT -5 scorplover said:

Scorp11, do you sell the black reproduction 2.52 sprockets for a 75 super stinger? Thanks!

I do sell those. They are 2.52 pitch, for a 1 inch shaft. I think the scorpion part number was 043611 off the top of my head. It ends in 611 I know

[scorplover]

Good to know scorp11. I may be in the market for a couple sets. Thanks!

[niobrarafun]

The Scorpion is a 1975 Whip. I was afraid that was the case with the white sprockets, any idea where I can source the black ones that will fit my model sled? Thanks again everyone for the great info!

[scorp11]

Jan 2, 2013 12:25:48 GMT -5 niobrarafun said:

The Scorpion is a 1975 Whip. I was afraid that was the case with the white sprockets, any idea where I can source the black ones that will fit my model sled? Thanks again everyone for the great info!

Try Chip. Maybe he can put a thinner sleeve in one of the standard whip ones.

[scorp11]

Talked to Chip today. He has the new black drivers you need for the 75 Whip. Give him a shout

[niobrarafun]

How do I get in contact with Chip?

[scorplover]

Chips email address is [e-mail] or his phone number is 860-965-2379. He's a good guy!

[scorplover]

Chip is also on this site as scorpiontkx890.

[niobrarafun]

Thanks! I will give him a call.