Looking for Belt size

[topherztoyz]

Picked up a early 70's Speedway Scorpion mini. Missing the drive belt, Can someone help me with the size I need.

 

[danford1]

I don't know the part number but you can figure out what belt you need. Measure the distance between the crankshaft center and the jack shaft center. Looks easy to do on your Scorpion. Next measure the diameter of the driven clutch.
Then you look at a chart and it will tell you what belt you need. You need to know if you have a 20 series or 30 series clutch.
Here is a website that should help you determine what you need Comet Drive Belts | Belts for Comet Torque Converters

Once you know the number - OldMiniBikes Warehouse has good prices on belts.

Danford1

 

[Ajf]

Its a custom size only made by speedway. I've never been able to find one that will work. It either too big or too small and there's no adjustment on speedways engines. Send me a pm and I'll give you contact info on nos speedway belts.

 

[topherztoyz]

I think its a Comet 30.. Motor side of Converter is flat... My Jack shaft pully OD is 5"Converter pully also is 5", 6 5/8 Center to center.. Thanks for help..

 

[Ajf]

People replace the original drive with a 20 series which is symmetrical and will use the original belt. Make sure you have the 20 series on the drive because your driven is an original symmetrical speedway product.

 

[topherztoyz]

I don't think my drive is a 20... Just stamped Comet industries, and I don't have a belt to measure, or compare too..

 

[CarPlayLB]

OldMiniBikes has the 20 series drivers here
https://www.OldMiniBikes.com/comet-20-series-drive-clutch-with-3-4-bore.html

the problem as AJF said, the shortest series 20 belt is for 6-15/16" center to center. Maybe use a 1/2" kart mount to raise the engine and look too sketchy? That way you may have the proper centerline measurement?