Odd rotor marks

Was calibrating my timing scale using Reg's straw-in-the-sparkplug-hole technique, and I noticed something odd with the rotor. Seems there's two timing lines in the rotor, about 180 degrees apart. One mark is engraved into an embossed area and looks like a factory job. The other mark appears to have been scratched in by hand and is hilighted with some red dye.

The hand job corresponds to TDC (actually, it appears about 5 degrees off) and the factory-looking one lines up with BDC.

Is this normal or is there something strange going on here that I need to investigate further?

Debby

Alt rotor marks

The commando uses the mark directly above and in line with the keyway. Some other model rotors are 180 out or have both....
Your nonstd rotor may have been marked for USE on a commando.
An atlas crank cheek used in a commando will also screw things up.

Debby,

Something strange indeed!

The mark on the raised boss is the one that the factory used.

How did you adjust your timing initially?

Jason

Debby,

The main thing is that you get a datum point for TDC (Top Dead Centre)
You will then be able to check your points opening timing.

If you static time your bike carefully, it will run very well.

Put the bike on the centre stand & place it in 2nd or 3rd gear.
Move the rear wheel back & forth until you are 28 degrees BTDC(Before Top Dead Centre)
You do need to "lock" your advance unit into the "fully advanced" position.
There is a special little washer type tool for doing this !

A cigarette paper or test light is needed now.
From your previous posts, I am assuming you would know that there is a high point on the round gizmo that opens your points as it spins around ?

Well, if you place the ciggy paper in between the points so that it is held by the points....then rotate the points plate until the point just start to open. You will just be able to "pull" the paper out when the points are opening at the 28 degree mark.

Remove the auto advance "locking" washer & your bike should be timed close enough to run very well.

I understand that you may have a problem elsewhere, but this is a good first step to getting the bike running.

Now what are you going to do next if this doesn't make it start ?


BTW, all this info is in the repair manuals & is probably explained better..

Debby,

Do not be concerned about the "odd timing marks" on your rotor at present.

This will not be stopping your bike from running.

I would doubt they are odd anyway.

Dave did say they can "screw" things up, but not in a timing/runniong sense.

Some cranks had a "stepped" key & it can be turned around so that when you time your bike, using the "factory" marks, they are "out"

DO NOT BE CONCERNED with all that.

What matters is that you find a datum for TDC & use it to time your bike.

My xmas wish is that you get this bike going b4 xmas arrives..............

Was just wondering about the strange timing mark. I think dynodave figured it out although I'd have to pop the chaincase off to say for sure.

Anyway that mark does work for timing the engine although the straw indicates that it's about 5 deg off, resulting in the timing being advanced by that much. That could explain the kickback. So I reset the timing in the usual manner but set it to an indicated 23 degrees to compensate.

I also checked the points gap and found it to be too big. Looks like I set it wrong last time. So I fixed that (before setting the timing!)

The bike now also has:

old fuel drained from carbs, lines, tank
chokes fitted
new plug wires

Am planning to try starting it this weekend, weather permitting (we have freezing drizzle at the moment), with fresh gas and the oil drained from the sump (has been over a month since it ran last). I think there's a good chance it will start. But then the real test will be to let it sit for a week and see if it will start again...

Debby

Debby,

Good luck with your Norton this weekend and exercise caution in that freezing drizzle.

Did you toss in some of those magical Autolite 63 spark plugs? I just installed some in my Norton (Champion wasn't available from my local autoparts). I can't tell any difference in engine performance over Champion plugs but I think the arthritis in my left hip is better.

Jason

Jason Curtiss said:

Debby,

Good luck with your Norton this weekend and exercise caution in that freezing drizzle.

Did you toss in some of those magical Autolite 63 spark plugs? I just installed some in my Norton (Champion wasn't available from my local autoparts). I can't tell any difference in engine performance over Champion plugs but I think the arthritis in my left hip is better.

Jason

Click to expand...

I rode my Suzuki to work yesterday! The ride home wasn't much fun. The sleet had switched back to rain by the time I left but it was 39 degrees and raining for the ride home. Bike commuting season is pretty much over around here I'm afraid.

I'm currently running the AP64s which are one step hotter than the AP63. The bike does seem to run better with them. Didn't know they help with arthritis. Is that like wearing copper bracelets? If so I'd better keep using them! I have arthritis in my knees thanks to some old knee injuries.

Debby

You need to install the "magic" plugs only when your commando is on the centrestand, otherwise you may not notice any difference :wink:

Installed while on the sidestand, they seem to lack that "magic"

It is a pity they only helped your "arthritis" Jason.