1997-2001 Honda CR250 – Top End Service – Part 10: Exhaust Valve Installation

How To Install The Exhaust Valve On Your 1997 – 2001 Honda CR250r

1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve InstallationThe Tools You Will Need Are:

  • 4mm Hex Wrench
  • Needle Nose Pliers
  • 2-Stroke Oil
  • Molybdenum Grease (Amazon)
  • Inch Pound Torque Wrench
  • Rubber Gloves

The Parts You Will Need Are:

  • Left Valve Cap O-ring – Part Number: 91302-001-020

If you don’t have your parts yet, you can get them from RockyMountianATVMC.com

Related: Should You Trust The Oil Injection System On Your 2-Stroke Motorcycle?

Click Here To Open The Top End Specifications Table In A New Window

Exhaust Valve Linkage Assembly

(Click To Start Slide Show)
Start by assembling the linkage.

  • Insert the bushing into the valve link, small side down
  • Install the spring with the spring ends facing up.
  • Compress the spring, and rest it in the stop.
  • Place the drive pinion on top of the linkage with the pin between the spring ends.
1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Assemble Linkage 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Linkage Assembled
Apply grease to the drive shaft bushing and driveshaft. Fit the bushing on the drive shaft, and Install drive shaft part way into the cylinder 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Grease Drive Shaft Bushing 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Grease Drive Shaft
Align the link assembly, and finish installing the drive shaft. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Align Linkage With Drive Shaf
Clip the driveshaft into the linkage. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Clip Drive Shaft To Linkage

Exhaust Valve Governor Install

Apply grease to the pinion shaft and bushing. Seat bushing in the crankcase. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Grease Pinion Shaft Bushing
Assemble the governor washers and engage the rack. Install the governor in the crankcase 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Install Governor and Rack
Install pinion shaft with the opening facing in. Double check the rack and pinion operation. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Pinion Shaft
Flap Valve Assembly
Apply grease to the flap valve shaft, and partially install it into the cylinder. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Grease Flap Valve Shaft
Install the flap valve with the projections facing up. Align and install the flap valve.

  • 97-98 – Through the exhaust port.
  • 99-01 – Through the cylinder
1997 - 2001 Honda CR250 - Top End Service - Part 10 - Exhaust Valve Installation - Install Flap Valve
Right Sub-Exhaust Valve Install
Apply grease to the exhaust valve shaft, and connect it to the valve. Top End Service - Part 10 - Exhaust Valve Installation - Asssemble Sub-Exhaust Valve a
Align the valve shaft with the flap valve, and place the sub-exhaust valve on it’s bore. Apply 2-stroke oil to the valve, then press the valve into the cylinder. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Install Valve Shaft
Turn the valve until the cutout is facing up, and install the stopper bolt hand tight. Top End Service - Part 10 - Exhaust Valve Installation - Install Stopper Bolt
Install bearings with the manufacturer’s marks facing out. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Right Side Bearings
Connect Valve Linkage
Seat the valve link against the end of the valve so the tab sits in the cutout. Rotate the valve counter clockwise, and insert a drift into the hole. Top End Service - Part 10 - Exhaust Valve Installation - Tighten Valve Linkage
Install the hex bolt and torque to 48 in-lb. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Torque Valve Linkage
Left Sub-Exhaust Valve Install
Lubricate the left Sub-Exhaust valve with 2-stroke oil. Align the valve with the valve shaft, and press it into the bore. Top End Service - Part 10 - Exhaust Valve Installation - Left Sub-Exhasut Valve
Lubricate and install the bearings with the markings facing out. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Left Side Bearings
Install the collar with the stepped side facing in, followed by the snap ring. Top End Service - Part 10 - Exhaust Valve Installation - Left Side Collar1997 - 2001 Honda CR250 - Top End Service - Part 10 - Left Side Snap Ring
Lubricate a new o-ring, and install it on the valve cap. Top End Service - Part 10 - Exhaust Valve Installation - Fresh O-ring
Apply grease to the valve cap threads, and install the cap hand tight. 1997 - 2001 Honda CR250 - Top End Service - Part 10 - Grease Valve Cap
Test Power Valve Operation
Tighten the hex bolt on the pinion holder temporarily, and test the operation of the exhaust valve system. Top End Service - Part 10 - Exhaust Valve Installation - Tighten And Test Linkage
Loosen the pinion bolt, as you will need to adjust the system after the cylinder is installed. Be Careful!
Exhaust Valve Torque Specifications
Linkage Hex Bolt 48 in-lb.
Pinion Hex Bolt 48 in-lb.
Part 9: Clearance Calculations Part 11: Piston Installation
1997 - 2001 Honda CR250 - Top End Service - Part 9 - Clearance Calculations 1997 - 2001 Honda CR250 - Top End Service - Part 11 - Piston Installation

 

Keep Your ’97-’01 CR250 Running Right!

Fix Your Dirt Bike Logo

This site uses Akismet to reduce spam. Learn how your comment data is processed.