Its Saturday (4/4/98) and threatening to rain again. Another good day to wrench on the scoot.

Today, I'm going to break more new ground; replace the stock 883 cams with the Andrews N2 cams. My choice of cams was directly related to how I will be using this bike. It will be my commuter and errand bike. I'll rarely drive it more than 30 miles from my house and nearly always divide my riding between street and freeway conditions.

The N2 is a high torque (low end) cam (i.e. it should get you from one street light to next quicker than the old blue-hairs can move their foot from the brake to gas after it hits 'them the light turned green about 5 seconds earlier.). According to Maurice, this sucker will pull a heavy load too. Good to consider if you've tended to workout in such a way that you now emphasize your ass and belly as your most prominent features as the years are passing by. Or say, your SO happens to like to consume an inordinate amount of Twinkies but not quite enough to tip the scales past the 900 lb. GVWR for your scoot.

This procedure assumes you've already removed all three of your rocker boxes and push rods, push rod tubes, removed your brake pedal from the pushrod going into the master brake cylinder, and removed your front exhaust muffler.

Disassembly is very easy. Preparation for it is more time-consuming.

Preparation:

1. Feel under the gear case cover directly and note where it butts up against the case. When you remove the cover, a small amount of oil will drip from this point so either put a rag, cardboard or thin long pan under that location to catch it. At the local grocery store I found I could by four aluminum foil 1" high by about 6" long oven baking pans for about $2. These are perfect for catching drips anywhere under your scoot.
2. Read and re-read the service manual and any other reference on removing and replacing 883 cams. The first edition of "Hot XL" in 1996 had a 'How to Do' pictorial article on installing a cam called Yes You Cam". You should be familiar with which cam is #1, #2, etc. before you start.
3. The gear case has 11 allen bolts that you'll remove in this process. They are four different sizes. They need to be replaced in the holes from which they were removed. Take a cardboard flap from a box and an awl and punch 11 holes into the flap. Number each hole. As you remove the Allen screws (I followed the torque sequence order in the service manual), stick 'them in the appropriate holes.
4. Put the transmission in 5th gear.
5. Have some assembly lube and a new cam gear cover gasket handy.

Disassembly:

First remove your tappets. To do this you'll need a small paper clip straightened out with just a little bend at the very end. You can use your paper clip or some other means and stick it down into the tiny hole in the center of the top of the tappet. Don't scratch the surface trying to stick it into the hole. Hook it, then slowly lift the tappet out of its bore. Repeat this for the rear jug tappets.

Next, remove the Allen screws holding the plate that holds the lower pushrod tube seals and the pushrod tubes onto the case. These are VERY tight.

Now remove the smaller allen that is 90 degrees to the one you just removed (These aren't so tight). It secures a small triangular plate to the case. Behind the plate are two guide pins with tiny o-rings on their ends. Remove the plate, guide pins and o-rings.

I filled coffee cup about 2/3's full of 20-50 wt. oil. Then I cut two rectangular pieces of cardboard with widths equal to the inside diameter of the cup and about twice as high as the height of the cup, then fashioned them into a + divider then inserted the + into the oil. Now I marked the cup so that I could remember which tappet came from which hole in the block (i.e. FE, FI, RI, RE) and placed the respective tappet into the appropriate location in the cup (If you mark the cardboard, the next morning the oil will have absorbed itself onto it and obliterate your marks).

1. Drill out the two rivets on the ignition cover and remove it. The ignition cover will have a BIG number 5 on it.
2. Remove the dust plate and paper gasket backing.
3. Mark the ignition plate and the gear case cover so that you can align it to the same location when you re-assemble everything later. Use the awl to mark (scratch) the gear case. If you use a pencil or something else that is easily cleaned off, you might inadvertently wipe it off in step 9; then you've lost all reference to where it goes upon re-assembly.
4. Remove the two long nuts holding the Hall's ignition plate in place. Pull it out of the gear case so its hanging.
5. Using a 5/16" socket, remove the nut holding the gold Hall's effect rotor onto the #2 cam’s shaft.
6. Remove the rotor.
7. Remove the Allen screws holding the gear case on. Remember, when you start to remove the case some oil will begin leaking (not enough to cup into the palm of your hand but enough to mess up the floor.
8. Remember the order you removed the Allen screws and place them on that cardboard flap you prepared ahead of time.
9. The gear case will most probably be stuck to the gasket. Using a rubber mallet to dislodge it or your hands carefully try to loosen it by pulling it from underneath. DON'T USE ANY TOOL TO PRY IT AWAY. The new gasket will NEVER seal at that point if you do. (A reminder here. The gear case bushing alignment with the cam gear shafts is VERY tight. That means the case will come straight out. There will be no side-to-side or up-down play in the case. You'll be amazed at how precise the alignment needs to be to ensure minimal wear on the bushings and the shafts.)
10. Once the shafts are clear of the bushings, you'll have to pivot the cover back towards the rear of the bike. Its rear edge is being tightly held to the bike by an oil line and the ignition pickup wiring. I had a rag ready to put between its pivot point and the front edge of the aluminum belt protector so I wouldn't scratch the rear edge of the gear case as I pivoted it back. --At this point its easier if you have a helper.--
11. Cause the engine to turn over buy moving the rear wheel such that the engraved line marking one tooth on the pinion gear (directly below the #2 cam gear (the largest gear) aligns itself into the gear cog that is marked by a dot on the #2 gear. When you've done that, you'll notice that all other lines and dots align themselves on the other three gears. Once you've got 'them all lined up, you can pull out the 4th gear (the rightmost gear, technically the front jug exhaust gear and cam, or the gear most forward of all the gears).
12. Replace it with the new #4 gear applying a liberal amount of assembly lube on the gear shaft going into the engine and the perimeter of the entire cam lobe and aligning it to the dot on the #3 gear.
13. Pull the #2 cam.
14. Pull and replace the #3 cam aligning it to the dot on the number 4 gear. The #3 gear might have two dots. If so, the proper way to install it is so that the smaller angle made between the two dots to the shaft center is directed towards the ground.
15. Pull the 1st gear and try to put the new gear in so that its aligned as the one you removed was. Might have to count some teeth and make a mark on the inner gear case to do this.
16. Now the simple part (ha!). Insert the #2 cam into its bushing such that all three of its dots line up. One with the #3 gear, one with the #1 gear and most importantly, the last one with the marked tooth on the pinion gear. That's it! You might push the scoot back and forth a little to insure the gears don't bind. Another method is to place all the gears in the gear case first, then rotate the #2 gear insuring there isn't any binding. (The Andrews page below will explain how to over come a binding cam.)

Now you can put more assembly lube on the protruding cam shafts, put a new gear cover gasket in place and carefully slide the outer cam gear cover back onto the four cam shafts. Be very careful to keep the gasket properly aligned. Replace the allen bolts tightened to the proper torque and you're cam gear replacement is 99.9% done.

The last step insures your gear shafts are properly machined and set into the case correctly.

16. Starting with the front jug's exhaust cam, rotate the engine (rear wheel) so that the high point of the cam lobe is point straight up into the tappet hole. Insert a flat screwdriver into the tappet hole in such a way that you can pry the cam lobe horizontally towards the outside gear case. Now insert the proper feeler gauge down the tappet hole to determine the end play is within service manual tolerances. You will be measuring the gap between the lobe journal and the inner brass gear bushing.
17. Repeat above step on the remaining three cams.

(Andrews Cams has a great web site explaining all this. Mark Dotson informed me of this URL.)

18. Properly install rotor and ignition plate according to your marks on the gear case (The rotor is notched and should only fit onto the #2 gear shaft in one location.
19. Use new o-rings, seals and gaskets upon reassembly to ensure you'll remain leak free and follow the torque requirements and sequences as described in the service manual.