Torque Specifications for a 1995 YZ250

In 1995, Yamaha's YZ250 off-road motorcycle featured a 249 cc, single-cylinder engine. As advertised, the YZ250 produces 47 horsepower and 31 foot-pounds of torque. Keeping this bike properly tuned will ensure that every part is working to its optimal performance. If you ride regularly and keep a consistent tune-up schedule for your motorcycle, it is imperative that all repairs be made to factory settings. When removing and installing parts, the nuts and bolts of the engine must be torqued to certain specifications for maximum performance.

  1. Cylinder Head Bolts

    • If you ever need to get down to the cams or cylinder port of the YZ250's engine, you will eventually have to put everything back together again. Before installing the bolts, check the washers for any rust or debris build-up. Throw these washers away and replace them if they show signs of significant wear, because they could potentially crack or break apart. All of the cylinder head cap nuts need to be torqued first to 14 foot-pounds, and then 27 to 29 foot-pounds to complete. The cylinder head bolts need to be torqued to 18 foot-pounds. When reinstalling the cylinder head cover, tighten the bolts to 7 to 9 foot-pounds of torque. Torquing these nuts and bolts to anything less could lead to rattling and separation of the bolts from the cylinder head, while over-torquing them could damage the cylinder head itself.

    Cam Sprocket and Tensioner

    • Line up the cam sprocket with the dots on the crank sprocket for accurate reinstallation. When reinstalling the cam sprocket, tighten the sprocket bolt to 14 foot-pounds of torque. The attached cam chain tensioner mounting and sealing bolts should both be torqued to 7 foot-pounds

    Clutch Springs

    • If you reattach the clutch springs and cover to the clutch assembly, torque these bolts to 7 foot-pounds.

    Radiator

    • It is important that the YZ250's radiator is serviced regularly. However, sometimes these units crack and need to be replaced. All of the screws and bolts that hold the radiator system in place should be torqued to 4.3 foot-pounds. The bolts of the thermostat opening, connecting to the radiator, should be torqued to 7.2 foot-pounds.

    Carburetor

    • Delivering the fuel into the intake manifold, the carburetor is another important engine part that should regularly be removed and cleaned in off-road motorcycles. The YZ250's carburetor bolts should be torqued to 1.4 foot-pounds, while the screws that hold the hoses to the carburetor need to be torqued to 2.2 foot-pounds.

    Exhaust Pipe and Silencer

    • Once all of the fuel and air mixture of the YZ250 has traveled through the cylinder to power the motorcycle, the exhaust pipe acts as the final stage in which this gas is emitted. The bolts and studs that attach the rear of the exhaust silencer to the bike's frame should be torqued to 25 foot-pounds. The exhaust pipe, exiting the engine block, attaches with 2 flange bolts that need to be torqued to 17 foot-pounds. The silencer clamp holds the rear silencer to the exhaust pipe, and should be secured with a bolt torqued to 14 foot-pounds.