"How do you size up the chain needed for a kart,"
You don't specify which problem you have.
Size of link or length of chain.
If it is size of link then you need to buy chain for a 100cc kart. This is often sold as kart 100 chain and the hole is (I think) 7.778 mm * 4.8mm.
Prokart chain (#35 type) is larger and chain for a 250 is larger still.
If it is the length you want, then a quick guide is to add the two sprocket teeth together and add 10. That should space the engine the right distance from the rear sprocket to allow the chain to flex properly.
The lengths between the front and rear sprocket should be able to flex between 1 and 2 cm. with the engine done up, pull the chain up then push it down in the middle of the length, the difference should be about 1 to 2 cms. If it is more than that move the engine forward to take up the slack, less than that move teh engine back.
If you use up all the movement on the engine mounting plate, change the number of links in your chain.
Most chains are bought made up to a fixed length, between 98 and 114 teeth. You can buy chain in lengths up to 10 feet, and special joining links and separating tools that allow you to break the long length of chain and make it up into sizes as you want.
Clearly a made-up chain is (in theory) less likely to go wrong than a split chain, but no doubt someone who uses split chains will tell you they have never had a joining link fail.
With use a chain stretches and wears. Get a brand new chain and hold it out sideways by one end to see how much it bends (droops) down to the free end. When a chain droops an extra inch, it is worn out and should be thrown away. (Some one might tell you that the chain can droop more).
A chain must be lubricated every time it is used. A dry chain will chew away both sprockets and wear the rollers within 3 laps.
If you look at the sprockets and the teeth appear hooked, they are worn out. It you look at the edge of a rear sprocket and the top of the tooth is less than half the thickness of the rest of the sprocket it is too worn and should be replaced.
Hope that helps.
|
|