Crank case

[metal mulisha]

on a 85 or 86 honda 250r does the crank itself use the "transmision or gear oil" or does it get lubed fromt he mixed gas? thanx alot

[plkmonster2]

on an r, there is not crank oil. The incoming oil/gas comes by the crank and up to the ports. It lubes it as it goes up into the piston. The transmission takes oil though, but not sure what kind. :?:

[metal mulisha]

ok thanxs. how exactly does it work? any more info would help.!thanx again

[plkmonster2]

It an odd process, but it happens fast, and makes tuns of power. When the piston travels up to the top of the stroke, the reeds in front of the carb are being sucked on. They open up, and let the mixture into the crank. Then the motor explodes at the top of the stroke. As the piston goes back down, the cylinder creates a vacuum since there is not enough air to fill in the space, so it sucks the fuel up into the cylinder. Remember, there is still exhaust gas to get rid of. As the piston heads back up, it pushes the exhaust as well as some fuel (this is why they use tons of gas.) out the exhaust. Then the exhaust port is closed since the piston has passed it, and then it repaets the process, suck in fuel, explode, push fuel in cylinder, exhaust, etc. 2 strokes have no valves, and fire every stroke, unlike a 4 stroke, which fires every other. The ports in a 2 stoke are placed to where they can push fuel up into the cylinder, and push the exhaust out in the same stroke. If you take the exhaust off, and look into the post with a flashlight, and put the piston at bdc, bottom dead center, you will see the intake ports, and the top of the piston. Spin it over more, and you will see how the pisont closes off the exhaust.