06-03-2015, 06:20 AM
(06-13-2013, 09:16 AM)Mikey350D_imp Wrote: Just got my Honda service manual, and it appears to be an excellent manual.
Its a long time before I need to check clearance but here are some things I have learned from wrenching on Honda CRF250's and CRF450's for many years. (head design appears very similar)
-You dont need special tool to back off the cam chain tensioner.
Use a small flat bladed screwdriver, back of tension then lock screwdriver in place with a small pair of vice grips (When valves need to be shimmed).
-Plug all oil gallies, in case you drop a shim: trust me on this one
-I found the best way to remove reluctant shims was with a piece of gorilla tape (clean off oil first)
-Shim size may be worn of by the time you check valve clearance, then you will need to measure shim with micrometer.
Record clearance gaps and shim sizes.
-Clean oil off cam chain and cam gear and mark position of chain on gear in 3 spots with a sharpie. Insures everything is correct when re-installing cams.
-Keep tension on cam chain as cams are removed, don't let in drop off bottom gear- tie up with a mini bungy.
-I always used a bit of assembly lube on shim, bucket, cam journals and cam lobes.
-Use a good quality torque wrench (I use Proto) in/lbs and ft lbs.
Here is what the "official" little Honda tool looks like. I had a credit on my part account at my local dealer so I ordered it. $100! (It does have a cool one-way bearing, though.)
Since most Hondas use this tool I don't feel too bad about the expenditure.