Depends on what you mean by "bike", and which one you choose.

If "bike" = bicycle:

Some bicycle computers are quite stupid, and will readily accept being programmed with a wheel circumference that wouldn't occur on a regular bicycle. One of these would work with a go kart.

You'd need to find a good place and a good way to mount the magnet, but otherwise, no big deal.

There is a slight risk that the bicycle computer might not be able to accept the speeds a go kart can reach.

If "bike" = motorcycle, it's probably trickier. Motorcycle speedos can have either a direct drive off the front wheel, or an electronic pickup in the gearbox. Either way, they're not as easily reprogrammed as bicycle computers.

A 3rd option is to use something GPS-based. Maybe even a cellphone app. Runkeeper or Strava might work. There are probably similar apps for motorized vehicles that'll do a better job.

A +5 kit from mykwilwin it makes is 5mph faster

2.3 billion

Golf World - Jonesboro

probably 10,11 or 12 to start riding one to age 60-75 to stop riding

30 MPH

No, They are still considered part of the Street.

it could mean the moter is blown or just needs a toon up

There should be 4 bolts on the underside of the engine mounts used to release the engine from the chassis, you then need to unbolt the remaining half of the engine mounts from the old engine and fit them to the new one (unless of course you have new mounts too) and re fit to the chassis ensuring there is not too much play in the chain. as for the tyres i'd try to get your hands on a tyre changing tool available from ebay, zoomkarts etc, if not just let the air out and persevere with a thin strong metal bar.

No, end of story. Those little old engines are only 1HP and don't like being revved over about 3000 revs. you probably wouldn't get much more than 10mph from it, and even then you'd need 2 gears.

i bought a 80 t back in december ,it lasted about 40 days before the clutch went out ,took it to dealership they said the clutch was not covered under 1 year waranty ,after i them that was bs and threatened to post on you tube was a pos they are they agreed to fix it under waranty .now 3 weeks latter it is doing the same thing it is a little over 3 months old and been in the shop for 3 weeks and now it is broke down again.i will take it back to laurel yahama tommorrow and i am already pissed off just thinking about trying to get them to fix it under warranty.i do not recomend these go karts they may seem like a weel built go kart but as far as i am concerned they are piece of junk