Norton Dominator 99 with K2F magneto

I'm not understanding the part of the prior post about there being a manual advance set up "(you could retard the ignition with cable, its now not in use anymore)." Could a manual advance have been installed by a PO to bypass a sticking AAU? Can you reconnect the manual advance unit and see how the bike runs?

Bodger said:

I'm not understanding the part of the prior post about there being a manual advance set up "(you could retard the ignition with cable, its now not in use anymore)." Could a manual advance have been installed by a PO to bypass a sticking AAU? Can you reconnect the manual advance unit and see how the bike runs?

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Prior to the advent of the AAU, the cam ring had a cable slot and the magneto housing had the mounting hole for the cable base. Twisting the handle bar control pulled the cable which rotated the cam ring clockwise, and retarded the timing.

Cam rings continued to have the cable slot after the AAU was fitted, probably so the same part could be used either in older (manual advance bikes) and newer models fitted with the AAU. Newer magneto housings had the cable mount hole blanked off.

If this bike has remnants of a manual advance cable setup, then some PO fitted the AAU as an upgrade.

Slick

There are different cam rings, for manual and auto advance.

Hello,

Before trying to do anything with the timing should i first buy the intermediate shaft support tool? I have always though it is necessary to have either that tool or cut open cover to tighten and loosen nuts for magneto and camshaft and also to get truthfull chain tensions.

I did quick inspection at the bob weights 2 days ago and i remember that those weights were kinda loosly in there, i mean you could wiggle them sideways pretty much.

But today after work i was planning on taking the AAU out and check it propely and also reset the timing. Or maybe i should first check the timing propely and then dismantle the AAU. But first if someone could tell should i wait until i've bought tool before even trying.

Thank you all.

KuusistoNorton said:

Hello,

Before trying to do anything with the timing should i first buy the intermediate shaft support tool? I have always though it is necessary to have either that tool or cut open cover to tighten and loosen nuts for magneto and camshaft and also to get truthfull chain tensions.

I did quick inspection at the bob weights 2 days ago and i remember that those weights were kinda loosly in there, i mean you could wiggle them sideways pretty much.

But today after work i was planning on taking the AAU out and check it propely and also reset the timing. Or maybe i should first check the timing propely and then dismantle the AAU. But first if someone could tell should i wait until i've bought tool before even trying.

Thank you all.

Click to expand...

When I was a poor college boy, I adjusted chains without the intermediate shaft support tool by working slowly and carefully ... i tightened, rotated engine, checked tension, then adjusted again if necessary. By all means, buy/use the tool if you can afford one.

You should remove, inspect, and repair if necessary the AAU before properly setting timing.

I do not think the timing is set in error if the timing chain is a bit loose, providing you follow the proper procedure to rotate engine backwards about 45 degrees, then slowly forward toward magneto set point. See my tutorial. Thus you can proceed before obtaining the support tool.

Slick

texasSlick said:

When I was a poor college boy, I adjusted chains without the intermediate shaft support tool by working slowly and carefully ... i tightened, rotated engine, checked tension, then adjusted again if necessary. By all means, buy/use the tool if you can afford one.

You should remove, inspect, and repair if necessary the AAU before properly setting timing.

I do not think the timing is set in error if the timing chain is a bit loose, providing you follow the proper procedure to rotate engine backwards about 45 degrees, then slowly forward toward magneto set point. See my tutorial. Thus you can proceed before obtaining the support tool.

Slick

Click to expand...

I use a sculpted dummy timing cover. Perhaps Slick can elaborate about checking the cam chain tension without using one. I understand you can turn the camshaft with a spanner to set the mag chain tension but I've never understood if this means turning it until there is or is not tension on the top run of the cam chain before proceeding to check the mag chain tension.

The hardest part of the whole timing procedure is making up a positive stop to find tdc and then triple verifying that you have tdc on the correct stroke. The next hardest part is getting the magneto sprocket back on the magneto taper without disturbing the timing. BTW once you have found 32 degrees btdc or whatever advance you intend to use, you can mark the stator and rotor so that next time you can use a strobe to verify. (Of course it's a PIA to make the marks while the degree wheel is attached and removing it tends to make everything move).

I would replace the oil pump conical seal as a matter of course whenever replacing the timing cover. Probably should also have a new timing cover gasket - make certain it's the thinner one for dommi engines unless someone has put a gasket behind your oil pump. Then there's always the question of whether it's worth replacing the crankshaft end seal in the timing cover while it's off. You have to consider the odds of buggering up the retaining groove getting the cir clip out, replacing the new seal facing the correct way and replacing the circlip sharp side out. Have fun and report back.

Update,

Took the timing cover off and checked the AAU bob weights and i couldnt find anything wrong with them. I was talking with friend of mine and after he heard that ot was arcing/sparking between points he said right away that it would be the condenser/capacitor.

Still running same as before. Idling perfectly and could idle all day long but wont rev and advance at all.

I'll try to check the timing tomorrow, i just need to figure out how to fit the degree plate to the alternator rotor since with the belt drive alternator is 10mm more out than normally.


Edit: Need to clean the slipring and check the condition of the magneto earth brush also tomorrow. I tried to clean the slipring and i got some black dirt sticking on the cloth but i stopped quickly because i was getting hits on my fingers..

Remove the points plate or earth the kill switch wire to avoid shocks from the slip ring.

The points always spark a bit. Condition of the magneto condenser is usually judged by engine performance. As said already, the typical symptom is reluctant hot starting.

texasSlick said:

Check the timing. Here is how to time a K2F ...https://www.accessnorton.com/NortonCommando/setting-up-and-timing-a-k2f-magneto.19685/

Click to expand...

Slick
If you have time I believe it would be worthwhile to replace the photo in your maggie instructions as the existing one appears to have the botophucket disease.
I have used your instructions previously and found them to be very helpful.
Cheers
Rob

robs ss said:

Slick
If you have time I believe it would be worthwhile to replace the photo in your maggie instructions as the existing one appears to have the botophucket disease.
I have used your instructions previously and found them to be very helpful.
Cheers
Rob

Click to expand...

Will do, Rob. Thanks for the heads up on the image, and thanks for the compliment.

Update 05.15.18 Image restored.

Slick

Hello,

Okay, ill be damned.

Took my time, attached the timing/degree plate to the alternator and then took the timing cover off. Left cylinder at compression stroke did the spoke in the hole and found TDC best i could.

I put 0 to the degree plate and rotated engine backwards to 60° BTDC. Fixed the AAU to full advance position with rubber tube and i took the center screw off from contact block, attached VOM as told in the tutorial and started to rotate it back to TDC and when audiable sound stopped i checket the degree plate and it was 13° BTDC.

Rotated it backwards again and took the tube off AAU and rotated it back to TDC, audible sound stopped it was showing 18° after TDC.

So my timing has slipped or did i check it wrong?

Most AAU had 12 degrees magneto advance. That is 24 degrees at the crankshaft. Your numbers 13 BTDC and 18 ATDC are total 31 degrees.

You might have:

1) an AAU with more degrees advance than the usual 12.
2) a PO may have ground material off the stop plate to gain more advance.
3) made some error in measurement.

In any event, your timing is very late. This explains the sympoms you have described.

You will have to pull the AAU. When you have it in your hand, look for a stamped number that tells the degrees advance. You can also get a degree measurement with a protractor.

Follow my tutorial to the letter, especially setting the point gaps equal on both ramps.

Report back.

Slick

texasSlick said:

Most AAU had 12 degrees magneto advance. That is 24 degrees at the crankshaft. Your numbers 13 BTDC and 18 ATDC are total 31 degrees.

You might have:

1) an AAU with more degrees advance than the usual 12.
2) a PO may have ground material off the stop plate to gain more advance.
3) made some error in measurement.

In any event, your timing is very late. This explains the sympoms you have described.

You will have to pull the AAU. When you have it in your hand, look for a stamped number that tells the degrees advance. You can also get a degree measurement with a protractor.

Follow my tutorial to the letter, especially setting the point gaps equal on both ramps.

Report back.

Slick

Click to expand...

Hello,

Im now trying to get the AAU off but its sitting tight in the taper. Any advice how to get if off? And am i supposed to get the center bolt off all the way?

I got it loose and if i try to unscrew it, it stops and wont get any looser.

Edit: and why is there 18° ATDC? I've though that it should also be BTDC and with full advance total would be 32° BTDC

Edit 2: I just mean that when im setting up timing shouldnt i want the audible sound to stop when the degree plate shows 32° BTDC or have i understood this wrong.

KuusistoNorton said:

Hello,

Im now trying to get the AAU off but its sitting tight in the taper. Any advice how to get if off? And am i supposed to get the center bolt off all the way?

I got it loose and if i try to unscrew it, it stops and wont get any looser.

Edit: and why is there 18° ATDC? I've though that it should also be BTDC and with full advance total would be 32° BTDC

Edit 2: I just mean that when im setting up timing shouldnt i want the audible sound to stop when the degree plate shows 32° BTDC or have i understood this wrong.

Click to expand...

Since you have gone to the trouble of attaching a degree wheel, why not make up a positive stop and verify that you have an accurate tdc data point. You can make up an easy positive stop from an inexpensive "top dead center tool" (the one with the plunger), by either brazing the plunger in place or drilling and tapping the body so you can use a bolt to lock the plunger in place.

Bodger said:

Since you have gone to the trouble of attaching a degree wheel, why not make up a positive stop and verify that you have an accurate tdc data point. You can make up an easy positive stop from an inexpensive "top dead center tool" (the one with the plunger), by either brazing the plunger in place or drilling and tapping the body so you can use a bolt to lock the plunger in place.

Re getting the AAU off, try tightening the bolt first. This should pop the AAU off the taper. Then unscrew.

Click to expand...

Hello,

Im not quite getting what you are trying to say with the positive stop tool, sorry..

What comes to removing the AAU, i want to make sure that you are talking about the bolt in the center of AAU the one that has U-shaped clip/washer underneath it. So i should try to tighten that screw to get the AAU pop?

Isnt that the screw thats used to tighten the AAU to the taper aswell?

KuusistoNorton said:

Hello,

Im not quite getting what you are trying to say with the positive stop tool, sorry..

What comes to removing the AAU, i want to make sure that you are talking about the bolt in the center of AAU the one that has U-shaped clip/washer underneath it. So i should try to tighten that screw to get the AAU pop?

Isnt that the screw thats used to tighten the AAU to the taper aswell?

Click to expand...

My mistake (bad memory). Should self extract just with turning counter clockwise, but it sounds like the thread may have stripped. Try pulling on it while you loosen. I've had this happen and remember it's a PIA.

From an earlier post by Texas Slick: Regarding self extracting nut: They work great when they work. When they don't, it is usually because they strip the internal left hand thread. Your method of a sharp rap with a hammer is first option if you can get some tension with the internal thread. If completely stripped, as mine is, then next option is a small gear puller.... back off the center bolt 1-2 turns, then pull on sprocket while pushing on center bolt.

AAU has an internal left hand thread that is supposed to self extract AAU. Try loosening until the bolt stops, then carefully try to make 1/4 turn more ..... This should engage the LH thread and put pressure on the mag spindle. Then give the bolt a rap with a hammer, and try another 1/4 turn .... repeat as necessary. The AAU will either pop off or the LH thread will strip as it often does. If the thread strips, you will need a gear puller.

If the AAU is stuck on the taper, it is doubtful it has slipped. That makes me wonder how your bike ever ran well in this condition. That aside, let's move on.

The AAU is set with the rubber wedge holding the mechanism in full advance. If you set to 32 BTDC, then with the wedge removed, the engine will be at 8 deg BTDC for starting (that is with a 12 deg AAU ..... 32 minus 2x 12 = 8). The factor 2 x 12 converts magneto degrees to crankshaft degrees. We normally do not worry about the timing point with the AAU in full retard position. Follow my tutorial and set to 32. BTDC. If you have high compression pistons, you may want to set to 30, or 28.

Yes, you do want the audible sound to stop at 32 BTDC (or whatever your target setpoint is) when rotating the engine forward. The sound stops when the points open, that is when the mag fires.

In lieu of Bodger's suggestion to make a tool, you can find TDC by following my tutorial. My method is within 1/2 degree and that is good enough.

Report back on your progress.

Slick

texasSlick said:

AAU has an internal left hand thread that is supposed to self extract AAU. Try loosening until the bolt stops, then carefully try to make 1/4 turn more ..... This should engage the LH thread and put pressure on the mag spindle. Then give the bolt a rap with a hammer, and try another 1/4 turn .... repeat as necessary. The AAU will either pop off or the LH thread will strip as it often does. If the thread strips, you will need a gear puller.

If the AAU is stuck on the taper, it is doubtful it has slipped. That makes me wonder how your bike ever ran well in this condition. That aside, let's move on.

The AAU is set with the rubber wedge holding the mechanism in full advance. If you set to 32 BTDC, then with the wedge removed, the engine will be at 8 deg BTDC for starting (that is with a 12 deg AAU ..... 32 minus 2x 12 = 8). The factor 2 x 12 converts magneto degrees to crankshaft degrees. We normally do not worry about the timing point with the AAU in full retard position. Follow my tutorial and set to 32. BTDC. If you have high compression pistons, you may want to set to 30, or 28.

Yes, you do want the audible sound to stop at 32 BTDC (or whatever your target setpoint is) when rotating the engine forward. The sound stops when the points open, that is when the mag fires.

In lieu of Bodger's suggestion to make a tool, you can find TDC by following my tutorial. My method is within 1/2 degree and that is good enough.

Report back on your progress.

Slick

Click to expand...

Hello,

So the timing has slipped afterall isnt it? If audible sound stops at the moment to 13° BTDC at full advance and it should be 32° BTDC?

I'll check the current timing at this moment once again and write it down. Then i'll pop the AAU off the taper and reset timing to 30-32° BTDC and see how it runs.

I should have modified spark plug somewhere and rod with welded bearing ball in other end. Everything inside the spark plug has been removed so theres only thread with center hole left. Screw it into place you have the rod pretty muchly centered to the plug hole and carefully rotating engine you can see where the TDC is. For more accuracy i guess i could set up dial indicator to the end of the rod and find it that way.

Thanks for the help.

Before setting the timing, report back on point gap on both ramps. I cannot over emphasize how important it is to have both gaps equal. Your bike will run so much better if equal.

Slick