Post #2 in this thread is a very good step by step how too by MotorBikeMike. http://www.motoredbikes.com/showthread.php?t=16555
The addition of pictures will always help. Like they say, "One picture is worth a thousand words". Good luck. Can't wait too see the pictures.
I finished the job in a little more than one hour, including the time to gather all the tools and chase down the ones I didn't have.
- 2 x 10mm open end wrenches (yes, two!)
- 8mm open end wrench (for compression release and holding lifters)
- 4mm Allen wrench
- 8mm Allen wrench
- Modified Screwdriver with end bent to 45-60 degrees
- Putty Knife
- Small deadblow hammer (I used a small sand filled hammer)
- Sandwich Baggie
- Paper Towels
(1) First, I always remove the battery, in case I make a wrong move and create a short. Use a 10mm wrench.
(2) Drain the oil. Remove plug using 8mm Allen wrench. Save into an appropriate container and dispose of properly (at a facility that takes used motor oil).
(3) Here's the right side of my engine before work:
(4) I have now removed the ten (10) Allen head screws holding the side cover using a 4mm Allen wrench. I used the plastic sand filled mallet and tapped a paint scraper along the opposite sides until it popped loose. My cam stayed inside the engine but yours may come out attached to the case.
(5) It took a little work to get the cam out as the opposite bearing seemed stuck. I used my bent screwdrive and wedged it in the small gap between the cam gear and the crank hub while simultaneously pulling from behind at the bottom of the cam. It took a little wiggling but it finally came out. The lifters then fell slightly and were stopped by the oversize nuts attached to the top of the lifters.
Here's a pic of the cam. Note the abrasion (galling?) marks on the cam lobe by the factory lifters. It looks worse that it is as I really can't even feel any disturbance to the surface of the cam profile using my finger. But then this engine had only 23 miles on it!
(6) I turned off the fuel valve and removed the fuel line attached to the valve.
(7) I unscrewed the top of the carb to free it from the cable and removed the two (2) 10mm nuts.
(8) I removed the compression release cover by removing the two (2) 8mm hex screws. My bike is so new that I was able to salvage the gasket but I'd plan on having a new one handy. Here's a peak inside the intake. It looks like a straight shot through the carb manifold with little restriction. I don't see anything to open up. Maybe somebody could comment.
(9) Hold the lifter with a 8mm wrench and break the lock nut using a 10mm wrench. It's a bit tight so don't allow the wrench to slip else you'll bruise a knuckle! I held the top of the hex screw with my finger and loosened the lifter by turning the lifter from the bottom. Then I pulled the lifter out and removed the hex screw with lock nut and set aside. I did this for both lifters.
(10) I ran the hex screws into the new lifters to make certain that there were no burrs on the threads. Then I put the screws back into into the compression release opening and inserted the new lifters from the bottom, turning the lifters until I had 1/8" gap between the top of the jam nut and bottom of the screw hex head.
(11) I then "lifted" the lifters using the cantilevered weight of my two 10mm open end wrenches so I could get clearance to push the cam back into the block. Here's the cam inserted with the two wrenches still in place. Be certain to advance the cam timing one tooth too.
(12) Now I rotated the rear tire so I was on a low spot on the cam and adjusted the hex screw to get 0.008" gap for the exhaust (toward exhaust pipe side) and 0.006" gap for the intake (toward carb side). I held the bottom of the lifter using a 8mm open end wrench and turned the top of the screw using a 10mm open end wrench. When I got close, I just gently trapped my feeler gage between the lifter and bottom of the valve, then I moved the 10mm open end wrench from the top of the screw to the jam nut. Tighten the jam nut against the top of the lifter.
(13) I then reversed everything and "attempted" to start the bike. Read my thread "Whizzer Won't Start" to follow that adventure!