How To Perform A Leak Down Test On Your 1997 – 2001 Honda CR250r
The Tools You Will Need Are:
- 48mm Expansion Plug
- Philips Screwdriver
- Leak Down Tester
- Spray Bottle With Soapy Water
The leak down test is a critical step in your CR250 rebuild because it’s an easy way to check your work.
If you have a bad seal or something isn’t torqued correctly, this will tell you.
Setting Up Your CR250r For Testing
Attach your leak down tester to the carburetor boot, and make sure the clamp is tight.
Slowly pressurize your engine.
If the pressure drops less than one psi in 5 minutes, you are good to go.
If your pressure drops immediately, or more than one psi in 5 minutes, it’s time to go hunting.
Hunting For Gasket And Seal Leaks
Place a towel over your crankcase to protect from overspray. The right crank seal is the last thing to test if you can’t find the leak anywhere else.
If there is any leak, you will easily spot the bubbles.
On this engine, the right front base gasket and exhaust valve stopper bolt are leaking.
The exhaust valve stopper bolt does not have a gasket or o-ring, so I wrapped the threads in Teflon tape and re-torqued, which did the trick. The base gasket and mating surfaces where in good shape, so all I had to do was loosen the bolts and gradually re-torque, which evened out the pressure and fixed the leak.
After you fix any leaks, repeat the leak down test, and if everything looks good, we can move on to the break-in process.
|Part 13: Cylinder Head Installation||Part 15: Engine Break In|
Keep Your ’97-’01 CR250 Running Right!
- Service Specification
- Clutch Replacement
- Carburetor Service
- Engine Top End
- Front Fork Maintenance
- Rear Shock Rebuild
- Wheels & Tires
- Kickstarter Inspection
- External Shift Linkage