Correct...jackshafts do not start untill you get up to 300. Most of the 240 kits are all the same. Ask the seller / maker...about the offset sprocket ( if they say you do NOT need to grind the frame ) it will not be center enough, And work/make the axle spacers so the chain is as close to the tire as possible ( 1/8 inch ). For a 240,.....I would check with trac dynamic, sponcer here. OR if you want money in a 240 check out single side arms..those kits are about $2000 more.