KTM 2012 250 SX-F User Manual

Common Maintenance and Repairs: Engine
21
any slack, then the bearing is bad. The rod should be
held in place and should rotate freely side to side,
but should not move up or down at all.
Checking the Main Crank Bearings for Wear
Tools Needed
 8mm T-handle or socket
 10mm T-handle or socket
 30mm deep socket
 13mm hex key
 Flathead screwdriver
Step 1: Remove the Piston
Follow all of the steps on pages 13-16 to remove the
piston. (Do not replace the piston)
Step 2: Unlocking the Crankshaft
In order to check the main crank bearings, the motor
will have to be taken off of TDC. To do this, locate
the hex screw underneath the water pump on the
right hand lower side of the motor. Remove the bolt
so that the crankshaft can rotate freely.
Step 3: Checking for Wear
Now that the crank can rotate freely, grab the top of
the rod (shown in picture 2.3) and start rotating the
crank forwards. The crank should spin freely. If there
is any sort of resistance or noise, then the main
crank bearings need to be replaced. If the crankshaft
doesn’t spin at all, then the entire crankshaft needs
to be replaced.

KTM 2012 250 SX-F Specifications

General

Engine Type	Single cylinder, 4-stroke
Displacement	249.91 cc
Starter	Electric starter
Transmission	5-speed
Cooling	Liquid cooled
Rear Suspension	WP Monoshock
Fuel Tank Capacity	7.5 liters
Compression Ratio	12.8:1
Bore x Stroke	76 mm x 54.8 mm
Fuel System	Keihin EFI
Frame	Central double-cradle type 25CrMo4 steel
Front Suspension	WP USD 48 mm
Front Brake	260 mm disc
Rear Brake	220 mm disc
Seat Height	992 mm
Ground Clearance	375 mm