Right side points cover removal

Hello,

1971 Commando 750. I need to reseal the right side cover. The manual shows using a slide hammer to remove the points breaker plate. Its rather unclear. Do I just need to remove the center bolt? Does everything pull straight out, including the advance mechanism? Any dis-assembly on the breaker plate? Do I need to mark the position of the plate? I dont want to break anything.
Thanks for the help.
MikeM

Hi Mike,
You won't need the slide hammer to remove the contact breaker plate, that is only held in there with two screws. The slide hammer is to pull the advance mechanism off the end of the cam. It won't make any difference if you mark the point plate position because once you pull the advance mechanism you will have to do the complete re-timing procedure anyway. While you are in you might just as well give some attention to the cam chain tension, maybe the oil pump, don't forget the oil bushing, oh and a new cam seal. Only one hundred easy steps, have fun.

GB

MikeM said:

The manual shows using a slide hammer to remove the points breaker plate. Its rather unclear. Do I just need to remove the center bolt?

Click to expand...

A slide hammer isn't always required. Once the points plate and 1/4" (26 tpi) AAU retaining bolt have been removed, a 5/16"-24 bolt can then be screwed into the AAU spindle threads and the head of the bolt lightly knocked "up-down-left-right" with a hammer until the AAU is released from the camshaft taper.

Thanks for the quick replies. Do I NEED to pull the advance mechanism to get the case cover off?
I need to reseal the outer case, its leaking like crazy.

Thanks MikeM

MikeM said:

Do I NEED to pull the advance mechanism to get the case cover off?

Click to expand...

Yes.

Thanks LAB,

Now as I am reading the manual there is a special washer I need to retime the engine. Is there an easy way to re time this thing you can explain in a nutshell? The manual is very confusing.
I can handle setting the points. Its the initial starting point. I have a timing light and a dwell meter.

Thanks MikeM

MikeM said:

Now as I am reading the manual there is a special washer I need to retime the engine.

Click to expand...

You can often use two washers with different internal diameters instead of the special washer as you need to be able to temporarily lock the AAU cam at its fully advanced position (bobweights out) for the initial AAU positioning and static timing.

Choose left or right cylinder and then set the crank to 28 deg. BTDC (full advance) with that particular cylinder on its compression stroke.

The AAU should be positioned so the points for that cylinder are just breaking when the points backplate is set in the middle of its adjustment slot range and with the AAU set at full advance, when you are sure everything is correct, the temporary washer/s can be removed and the AAU bolt fully tightened.

The contact breakers can then be accurately set (preferably with a strobe) in the normal way for each cylinder.

The points cam rotates on its shaft for timing advance. The special washer allows you to lock the cam in full advance (against spring tension) while setting the static timing. When I had points, I preferred to use my fingers to twist the cam back and forth and get it such that the points contacts just opened when the cam was full advanced.

Remember to seat the tapered AAU shaft lightly at first so you can rotate the whole assembly with the points plate centered for maximum adjustability in final timing. It's frustrating to get to strobe timing and discover you've run out of adjustment range and aren't quite at 28 yet.

I JB Welded 2 washers together so they didn't keep falling out of registration on the cam. I stick it in a baggie and keep it with my ignition parts. Remember, the plugs fire when the points open. As I remember with the pistons TDC, the pivot points on the weights lines up with the holes that mount the adjustable timing plate, but don't quote me on that, it's a rough estimate anyhow, the strobe tells all. Make sure your cam is not loose on the shaft or you will have a dickens of a time adjusting the point gap and the resulting timing point. If you've got over 10K miles on the AAU it's probably worn enough for a rebuild, see the AAU thread where Per put a bronze bushing between the cam and shaft.

Dave
69S

Yep, no short cuts on messing with a real Commando, AAU must come off to get TS cover off. May need to go to hardware store to get an allen bolt to fit in the outer threads of the AAU to tap it loose off tapper. No one I ever heard of but the manual writers use a slide hammer.

DogT is so right about no short cuts to put back on correct static timing, ie: must stable seat the AAU on its tapper to have a chance of setting points plate near right on static timing. Just don't smack it on so hard its thread damaging to unseat for next diddle of static timing. Best way I've found is put a test light grounded on engine fin and other clip on points spring, then turn engine, I put in 4th on center stand and use tire to bump around, till light just comes on and check its near the 28' or 32' advance mark on factory dial, or better yet knife slice mark on alternator stator and correct slash mark of magnetic rotor. Can not trust the factory dial until degree'd wheel indexed as may be off over 10', ugh.

To me the AAU clamp washer just gets in the way so I use a small screw driver or probe to hold the AAU full advanced while diddling above. You need to put in the long AAU retaining bolt lightly torqued to keep AAU form wobbling to fool ya on where the points actually open with nipped up for road going.

Once running the timing light should reveal how much spread in spark time of each point to go back and forth setting each point and diddling back the separate points gap. If the AAU is worn much, and likely is some points spark spread helps to return to idle yet allow nice enough on road response. I learned to set one breaker for best start and the other for best hi rpm runing, which first happened to me by pure accident, but second time on 2nd points bike realized the reason for worse and worse operation - the better and better I got both breakers to land as optimal as possible UGH. Last month Wes and I did this on Trixie to get very stable almost identical 28" time light reading but ran so high an idle was annoying to dangerous to ride on THE Gravel, so much so ordered Pazion SureFire which failed to even run, so put together an AAU for best parts of two of them and enjoyed normal operation last 3 wks on contact breakers and now have spare unwanted replacement SureFire to sell off at INOA rally.

If ya do give up on points/AAU, send you left overs to me please.

With 12v test light hooked to fin and breaker spring, making sure of correct side to fire with piston approaching TDC by its valves going slack, I put point plate at mid slot and slowly turn AAU while holding-turning with probe to keep at full advance, trying not to let it wobble much till light winks on, then nip of AAU lightly and see if light still comes on at right time, then repeat for other set, then check the gap is right or go back and do it again with the gap reset for correct dwell and opening point on cam rise.

As far as parts go, you'll need the oil pump seal - a small rubber disc that goes on the oil pump, and needs to be replaced when the timing cover comes off (don't be tempted to re-use), a proper timing cover gasket (Commandos use a thicker one than previous twins, so get from a reputable parts supplier) and the timing cover points seal. As others have pointed out, look at the cam chain tension while apart. Also might want to buy the inner timing cover crank seal. Not saying it's bad, but while you have everything apart, that would be something I would at least buy and have on hand before a timing chest tear-down. It would be a shame if you had to wait for one.

Hobot - Did MAP send you a replacement Pazon or is this still the one you couldn't get to keep running?

MAP-Marino sent me a new 'amplifier' brain box only, as costs him $35 bux for Pazion to test them. But its brand new so wires not cut to length nor terminals afixed so will leave it that way for someone else to fit. Electronic ign. is not factory enough for the proper vintage baseline Combat I seek. Cheap couple hundred+++ dollar versions electronic ignitions ain't nearly good enough for what my non vintage Norton Peel needs. Only proof I have that Pazion had intermittent brain failure is I got Trixie running on breakers before and after the Pazion. Now I'm not sure if just worn air leaking slides keeping Trixie from settling down fast to slow idle or still slack in the scabbed together AAU. Amal slides are definite fluted worn but waiting to see what I find at INOA rally and who might take new in the box SureFire off my hands.

Don't forget when you install a new seal on the points housing you must protect the lip of the seal from being cut by the sharp edge of the camshaft as it enters the seal. Lightly grease the lip of the seal and either use the factory seal guide or a small socket inserted into the seal so that when the cover goes on the end of the cam pushes the socket out of the seal. The biggest cause of leaky timing covers is usually a worn or damaged points seal.

Mick

Thanks for all the great help.
I have the cover off cleaned and am waiting for a couple of seals. I managed to bugger up the points connectors and have to do some rewiring.
My main hurdle will be to get the timing reset. I have the manual and some great information from the forum.
Thnaks MikeM