MK III Rotor (Mis)positioning

Hi,

I am in the process of removing and remounting the rotor on my MK III due to it having apparently been mounted 90 degrees from the position it should have been mounted. The reason I say this is that after performing a static timing of either set of the points (stock ignition), there is no rotor index mark showing in the primary case inspection timing port. According to the shop manual that I have (and unless I am completely misreading the instructions), when the points actuator cam index mark is in position for adjusting the points gap the rotor index mark should be visible in the primary case inspection port. My assumption is that one rotor index mark or the other should be viewable. Is this correct or am I missing something in my read of the procedure?

The second question concerns removing the rotor retaining nut. The P.O. apparently not only mounted the rotor improperly, but also did not possess a torque wrench as the nut holding the rotor on the end of the crank is near-impossible to remove. I am using a 1/2" W socket with a 24" breaker bar using the procedure documented in the shop manual (engage first gear, lock and hold the rear brake) and the engine rotates and the rear wheel turns. The force that I have been exerting appears to be sufficient to cause the rear brake to slip, or my "mechanic's helper" needs to lift more weights! Does anyone have an idea on a harmless technique for locking the rotation of the drive-train while force is being exerted on the rotor retaining nut?

Since I acquired the bike I have only verified that the points gap seemed to be set correctly and now I would like to tune using dynamic timing.

Thanks in advance.

ColoCommando said:

engage first gear, lock and hold the rear brake

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hi colo try engaging top gear, if your using a 24 ins bar it does seem overly tight have you tried heat on the nut or shock treatment

Even though the screws in the case were amazingly tight, and I had to drill some out my rotor nut came off amazingly easily!!! Guess I got lucky

The Mk111 rear disc brake has an amazing capacity not to grip when faced with high loadings from stationary. In use it seems fine but it slips and skips as if badly glazed when used to prevent the wheel from turning.

A good whack with a copper hammer on the extension bar may shock it off or else stuff a rag in the primary chain to help hold it.

Are you doing a full rebuild ? If so then you could place a bar through the rear wheel spokes :roll: (No, I can't believe that I've said that, but if the wheel is to be re-spoked then it shouldn't hurt).

chris plant wrote:
try engaging top gear, if your using a 24 ins bar it does seem overly tight have you tried heat on the nut or shock treatment

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Hi chris ... no, I hadn't tried any more radical techniques other than old-fashioned brawn. I'm a little reluctant to take a torch to that particular area of the primary drive, but would consider it if I felt that the risk of damage was minimized. I would not care for direct application of heat to the retaining nut and might consider trying heat transfer using the 1/2" W socket. Have you ever attempted such a process and, if so, did you have any success? But perhaps I am worrying about the risk a bit too much.

79x100 wrote:
A good whack with a copper hammer on the extension bar may shock it off or else stuff a rag in the primary chain to help hold it.

Are you doing a full rebuild ? If so then you could place a bar through the rear wheel spokes

Click to expand...

All I have is a brass hammer - I hope that will work! The rag in the primary chain sounds like a good suggestion. And no, this is not a rebuild. I am actually trying to get the bike running well and on the road so that I can get to the INOA rally in July.

Impact Driver (you can get electric ones if you don't have air) will do it too.

ColoCommando said:

Have you ever attempted such a process and, if so, did you have any success

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hi colo, yes i have used the hot spanner many times, and yes with success the sucker always lets go in the end,remove the alternator first to avoid damage i use a welding torch as opposed to a blow lamp to get more heat in more quickly,but this is when all else has failed iv,e heard of putting a peice of wood on the bottom run of the chain to lock the clutch,but as the bottom run of the chain is pretty close to the chaincase care should be taken to avoid the chain coming into contact with the chaincase or you could crack it,a better way might be to put a peice of wood on the bottom run of the rear chain up against the sprocket and hope fingers crossed the clutch dose,nt slip

swooshdave said:

Impact Driver

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thats also a good idea ,i have an impact screwdriver with 1/2 ins drive that takes sockets

I'd also use an impact.

ColoCommando said:

I am in the process of removing and remounting the rotor on my MK III due to it having apparently been mounted 90 degrees from the position it should have been mounted.

Click to expand...

You cannot move the position of the rotor relative to the crank position = because the rotor is keyed to the crankshaft. [Edit: Or at least, it should be?]

ColoCommando said:

The reason I say this is that after performing a static timing of either set of the points (stock ignition), there is no rotor index mark showing in the primary case inspection timing port. According to the shop manual that I have (and unless I am completely misreading the instructions), when the points actuator cam index mark is in position for adjusting the points gap the rotor index mark should be visible in the primary case inspection port. My assumption is that one rotor index mark or the other should be viewable. Is this correct or am I missing something in my read of the procedure?

Click to expand...

I don't think you have understood the instructions, as the points cam mark is for setting the points gap, this position occurs some degrees after the spark is produced, because the spark happens when the points begin to break and not at their maximum opening point. Note that you need to lock the auto advance unit at the fully advanced position (bobweights fully out) before doing the static ignition timing check, each set of points should be set so they are just breaking as the rotor mark lines up with the 28 degrees BTDC mark.

Also...

As it is a MkIII, you can double-check the rotor timing mark with the crankshaft timing slot, which should line up in the timing port (located in the crankcase below the timing cover) at 28 deg. BTDC.

Well guys, the impact driver did it. Thanks for all of the suggestions.

L.A.B. wrote:
You cannot move the position of the rotor relative to the crank position = because the rotor is keyed to the crankshaft.

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As I discovered as soon as I pulled the rotor off of the crankshaft. Next time I will research the parts catalog before I jump to conclusions.

L.A.B. wrote:
I don't think you have understood the instructions ...

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And you would be 100% correct. In reading the procedure, I didn't get the that the rotor index mark should appear in the inspection port when the points begin to open. I have never dynamically timed either of my bikes and never opened the primary case inspection port. Lesson learned.

L.A.B. wrote:
As it is a MkIII, you can double check the rotor timing mark with the crankshaft timing slot, which should line up in the timing port (located in the crankcase below the timing cover) at 28 deg. BTDC.

Click to expand...

I didn't know about that. Thanks for the tip.


A general forum question - I cannot seem to get the quote marks to appear on the same line as the "XXX wrote:" line. For example, the above quote was produced by the string: [.quote][.b]L.A.B. wrote:[./b][NewLine]As it is a MkIII ...[./quote] (leading periods inserted to show control codes). Is there a profile option that forces a new line after the "quote" and before the first text character that is entered?

That timing port is nice... I knew it was there, but not how to use it. Makes me feel a little better about when I put my new ignition in.

We all learn. With me, it's almost always the hard way. :roll:
If after all your timing, it is still off, the problem lies with Auto Advance unit.
It is not keyed and is a tapered fit. Subsequently, it's possitioning is infinite.
Consult a manuel to get it to a static position, then fine tune it.

ColoCommando said:

A general forum question - I cannot seem to get the quote marks to appear on the same line as the "XXX wrote:" line. For example, the above quote was produced by the string: [.quote][.b]L.A.B. wrote:[./b][NewLine]As it is a MkIII ...[./quote] (leading periods inserted to show control codes). Is there a profile option that forces a new line after the "quote" and before the first text character that is entered?

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Are you replying using the Red on White "Quote" button at the right of the members message you intend to quote from?


As that should give you [.quote="member name"]......the quoted text......[./quote]. Note that I disabled it as you did, otherwise it would show as:

member name said:

the quoted text

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Les,

No, I wasn't using the Red on White "Quote" button - I didn't understand it's usage. I was using the "quote" button above the reply edit window.

L.A.B. said:

Are you replying using the Red on White "Quote" button at the right of the members message you intend to quote from?

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I highlighted the above quote in your latest post and when I pressed the Red/White quote button, the above string was inserted into my reply edit window. I then pressed the "Preview" button below the reply edit window and the same string appeared the the preview window, just as I believe it will post into the forum. That is, as an "unquoted" string.

And, in fact, it did appear as a string - something is definitely not working as advertised.

ColoCommando said:

And, in fact, it did appear as a string - something is definitely not working as advertised.

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OK, then I can only suggest you check your BBCode setting is enabled, as I suggested to Robert_Norton who appeared to be experiencing a similar problem recently. However I don't know if he has checked this now, or not? post35422.html#p35422

Perhaps you could check your settings using the instructions I gave him, and see if that is the cause of your problem or not, as most of us do not seem to be having any problems with this?
If it isn't caused by disabled settings then I will make Jerry aware of the problem, as he may be able to identify what the cause could be?

L.A.B. said:

OK, then I can only suggest you check your BBCode setting is enabled, as I suggested to Robert_Norton who appeared to be experiencing a similar problem recently. However I don't know if he has checked this now, or not? post35422.html#p35422

Perhaps you could check your settings using the instructions I gave him ...

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Les,

I followed the instructions that you gave to Robert_Norton and, as you can see above, all is well. Thanks for the help.