1997-2001 Honda CR250 – Top End Service – Part 12: Cylinder Installation

Fix Your Dirt Bike

Sep 5, 2018

262

How To Install The Cylinder On Your 97-01 Honda CR250

The Tools You Will Need

Piston Holder
Motion Pro Torque Wrench Adapter → https://amzn.to/4g2Moy8
Foot-Pound Torque Wrench → https://amzn.to/3DOqm4B
Inch-Pound Torque Wrench → https://amzn.to/4j9LDpC
4mm Hex Socket
17mm Socket
14mm Socket
12mm Socket
8mm Socket
Lithium Grease → https://amzn.to/3ChhKTB
Shop Towels
Safety Glasses → https://bulltru.com

The Parts You Will Need

New ’97-’01 Honda CR250 Bottom End Gasket Set → https://amzn.to/42jJKkd
New Right Cylinder Cover Gasket → See Above
New Cylinder Alignment Dowels → https://amzn.to/3DVxPPm

Pre-Service Notes

I recommend opening the Service & Torque Specs in a new tab for easy reference.
If you need parts and tools, make sure to buy them here! → https://amzn.to/4h4lDKq
Pictures with captions are below after step b.
If you need any help don’t hesitate to ask!

Cylinder Installation

Double-check the cylinder bore and mating surfaces for cleanliness.
Apply lithium grease to the exhaust valve pinion joint.
Install NEW alignment dowels on the left side of the crankcase.
Install your new gasket.
Place your piston holder, and rotate the crankshaft so the piston skirt rests against the holder.
Double-check the piston rings are seated against the locating pins and position your cylinder.
Hold the cylinder as level as possible with the piston and compress the top ring against the alignment pin.
The cylinder should slide right over the ring.
Repeat with the second ring.
It Is Extremely Important That You Do NOT Rotate The Cylinder!
Remove the holder and align the exhaust valve drive shaft.
The drive shaft opening should face the rear of your bike.
Lower the cylinder onto the studs.
Thread the cylinder mounting nuts finger tight.
Tighten the exhaust linkage pinion bolt hand tight and check the exhaust valve’s operation by pulling and pushing on the governor.
Begin torquing the nuts in the same pattern as removal.
Turn the nuts ¼ turns at a time, making as many passes as necessary to reach torque.
Torque the cylinder mounting nuts to 29 ft-lbs.
Remember, when using the torque adapter, you will NOT need to compensate for length if the adapter remains at a right angle to your torque wrench.
Loosen the exhaust linkage pinion bolt, turn the valve all the way counter-clockwise, and check that the flap valve is open.
Torque the pinion bolt to 48 in-lbs.
Install the right cylinder cover with a new gasket.
Torque the valve stopper bolt to 141 in-lbs.
Torque the left exhaust valve cap to 115 in-lbs.
Torque-check the head studs and install the right crankcase cover.