Two stroke or four stroke?

[ROLY239]

Just got out of building a predator 670cc buggy. im looking to build something fast and low to the ground now. Will have the frame of a shifter kart single seater. Don’t know what engine to choose for the project. I want something quick though, maybe even with gears?

 

[mckutzy]

If it had a 670, then something of that caliber to refit... a typical motorcycle has about that and a transmission..

 

[bob58o]

If it had a 670, then something of that caliber to refit... a typical motorcycle has about that and a transmission..

Two different projects...
One was a 670 buggy, Now wants a shifter race kart.

---------- Post added at 09:18 PM ---------- Previous post was at 09:17 PM ----------

Don’t know what engine to choose for the project. I want something quick though, maybe even with gears?

What's the budget for the powerplant?

 

[ROLY239]

I would say the engine has to be less than 700-800$

 

[anickode]

200cc lifan 4 stroke on an old race frame.

Don't kill yourself with it.

Is it an actual shifter kart with front brakes, or a normal race kart?

 

[itsid]

two stroke.. OF COURSE!

if by quick you mean "close to originally quick"
find a 125cc two stroke pitbike engine (22-35 horses) and go with that

half the power at twice the weight will be not nearly as fun
but true a 200cc chinese 15 horse is a decent toy to fool around in the backyard.
and it's cheap...

but if you can spend 700 bucks.. then there are surely some better options!

'sid

 

[anickode]

Depends on the kind of maintenance you want to have to do as well.

A 2 stroke race engine will require frequentaintenance and rebuilds.

A 4 stroke pit bike engine is designed just to run. Granted, they don't run as hard, but they're way cheaper than to keep up.

 

[itsid]

Depends on the kind of maintenance you want to have to do as well.

A 2 stroke race engine will require frequentaintenance and rebuilds.

A 4 stroke pit bike engine is designed just to run. Granted, they don't run as hard, but they're way cheaper than to keep up.

true,
but it's not that bad as race kart engines..
not nearly!
take a cr125 for example.. (42 horses)
the only close maintenance schedule is the reed valve, transmission oil and the spark plug.
two of which are about as difficult as picking a nose;
the other as difficult as removing the carb.

the piston pin and it's bearing is due every 22hrs (machine hours that is)
Not great, but not too bad either.

Road legal bikes (say older Aprilia AF1 Futuras or Honda NSR125s)
are fine with even longer maintenance cycles.
~26 hrs until you need a screwdriver
(at the price of ~10horses less [32hp or 35hp])

not much inferior than any four stroke
(Lifan has a 30hr maintenance cycle on the 200cc air cooled five speed 16horse IIRC)

That's why I said to keep it between 22 and 35 horses

'sid