the chasi comes with a non- pull start engine mount. you will have to buy a pullstart mount in order to use a pull start engine. If you are intrested i can sell you a .15 thunder tiger(the one that comes on the rtr version). it doesnt have a pull start on it but you can buy a replacment one for cheap. IT has the pullstart mount and also has a pull start flyweel. you will need clutch bell and shoes aswell. Its not brand new but it is still going strong. shoot me a e-mail: [email protected].

In order to start a non-pullstart engine you will need either a starter box(60-150 bucks) or you can go the cheap route like me and bought a hand held(20-30 bucks) and a rubber adapter wheel to start the engine. hope this helps

a .12 engine is used for racing beacasue it has a high rpm and better fuel efficiancy then a larger engine. although it can have less tourque

a .15 is the ultimate sport size engine for stadium trucks. it has plenty of torwue and good rpm. if you are going to be bashing with the occasional "club level" race a .15 is the way to go.

.17 isnt very common other then in a duratrax stadium truck. there isnt very many engine manufactures that make .17 size engines for cars and trucks.

as a general rule .12s and .15s are used in stadium trucks. now if your not new to the hobby and can do some tricky modification it is possible to mount a .21 in a truck but i strongly do NOT recommend trying this. i have been in the rc nitro sceme for 7 years and wont touch any kind of modification like that.