How To Inspect The Exhaust Valve On Your 97-01 Honda CR250
The Tools You Will Need:
- Stiff Brush
- Shop Towels
- Parts Cleaner
- Dremel
- Digital Calipers (Link to Amazon)
- Emery Paper
- (Master Tools & Parts List Below)
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 on Amazon!
- Pictures with captions are after the steps below.
- If you need any help don’t hesitate to ask!
Exhaust Valve Cleaning
The exhaust valve components are in direct contact with exhaust gases, so the carbon build-up will be substantial. If you have the time, soak all the parts overnight in brake cleaner and degreaser.
- Scrub every component thoroughly with a soft bristle brush.
- If your valve components are as bad as mine, you can use a steel brush on a drill for the big stuff, followed by a light sanding with a Dremel.
- However, to avoid gouging or uneven surfaces, I will need to follow the Dremel with fine-grit sandpaper.
- Visually inspect every part for apparent signs of uneven wear or damage.
- Inspect the valve bearings for smooth operation. If they snag or feel rough, they need to be replaced.
Related: Shot-peened parts are stronger, last longer, and are definitely worth the money!
Exhaust Valve Measurements
- Measure the valve and flap shafts at their contact points.
- Both shafts should measure no LESS than 0.196 inches.
Exhaust Valve Governor
- Clean the governor and pinion shaft.
- Make sure the rack and pinion shaft grooves are straight and mesh smoothly.
Part 9: Clearance Calculations →
Top End Rebuild Tools List: (Links to Amazon)
- Piston Pin Puller
- Piston Holder
- Machinists Straight Edge
- Feeler Gauges
- Telescoping Bore Gauges
- Digital Calipers
- Plastic Scraper
- Spark Plug Thread Follower
- Motion Pro Torque Wrench Adapter
- Molybdenum Grease
- Lithium Grease
Top End Rebuild Parts List: (Links to Amazon)
Keep Your ’97-’01 CR250 Running Right!
- Service Specification
- Clutch Replacement
- Carburetor Service
- Engine Top End
- Engine Bottom End
- Brakes
- Exhaust
- Front Suspension
- Rear Suspension
- Wheels & Tires
- Kickstarter Inspection
- External Shift Linkage
