Bogging down/ rough running problem

[mbmm350s]

Hi Matt,
There may be cracks in the resin and there is no fault with the pick up or vice versa.
Even with careful measurements and heating and cooling of some pickups i have been unable to conclusively prove the fault exists on the bench,
and only by substitution do i know its faulty.

Anyway its not yet decided if any of these things are at fault, so it is not yet the time to decide about replacements.
The checks to be made are in the manual (blue book)

The stator is for a Franco Morini engine not Moto Morini, as far as I know no direct replacement stator is available for standard ignition based Moto Morini air cooled V twins, in any case the stator can be rewound. Not sure if you have already had the ignition low tension coil rewound.
Cheers
Mark

[norbert]

Have you allready checked the right ignition with a stroboscope lamp?

I know well the problem with the pickup when the motor becomes hot (2 times travelling in England and Italy). That problem I only had with the red pickups. You stop, doing anything and then when you start again, you think, "that was it, how smart am I", everything fine, for about 3-5 minutes and then the same thing again. To me it feels like running out of gasoline (one of the carbs quits before the second). Ususaly the misfiring or missing spark begins on one cilinder, not the two at the same moment. But I also know the sudden death of the red pickup (without any spark on one cilinder or the two).

With the black pickups this problem normaly does not appear (that often), because one of the heat sensible components (a diode or whatever) moved over to the buckeld grey boxes under the tank.

If you have the red pickup, try to find someone who can lend you another one to test it, to be sure that the pickup realy is the problem and avoid to spend a lot of money that may not solve the problem

If the motor starts easily the ignition coil of the stator cannot be that bad. You cam measur the resistance between the green wire coming from the stator and ground when it is cold and with warm motor. My experience says that normaly starting problems begin with less than 180 ohm. But yours starts well ...

Ah, I remeber my trip to England/Ireland in the early 80s with a starving red pickup: I could get home riding without the cover of the pickup! Three days later the pickup broke down toaly Try it! When the problem disapears, you know that you have this overheating problem with the pickup. And that will not get better!

[Matt Hale]

Many thanks again Mark- I will see if I can find a substitute red pick up and if problem disappears! I have had the small ignition low tension coil rewound. They said they couldn't do the others battery seems. to charge fine..Also thanks for identifying that I had teh wring stator on e-bay!

[Matt Hale]

Thanks Norbert- yes I do have the Red pickup and will see if I can find replacement to borrow and see if its the issue. I may just throw money at it and buy a replacement- just sold my Laverda 3ce for good money so Morini can have some!

[BumbleBee]

There are club members who would rebuild pickup units for you at a reasonable cost. Mostly they are rebuildable, not always.

[mbmm350s]

I know well the problem with the pickup when the motor becomes hot (2 times travelling in England and Italy). That problem I only had with the red pickups. You stop, doing anything and then when you start again, you think, "that was it, how smart am I", everything fine, for about 3-5 minutes and then the same thing again. To me it feels like running out of gasoline (one of the carbs quits before the second). Ususaly the misfiring or missing spark begins on one cilinder, not the two at the same moment. But I also know the sudden death of the red pickup (without any spark on one cilinder or the two).

Norbert, that is so true and I like the way you describe it. Its like one carb is out of fuel or something.
If the common earth breaks then both cylinders stop firing.

but the fault could be something as simple as a corroded spark plug lead.

Cheers
Mark

[Matt Hale]

Thanks Bumblebee and Mark- I may need a rebuild of pickup...I need to strobe the bike also but when I try the dam strobe doesn't flash...not sure how to test it- it's new but maybe faulty- any ideas how test? The corroded plug lead - I have clipped the ends of the leads at spark plug end and also coil end.
The caps are new rubber NGK's...all a bit frustrating but winter will be here soon so I won't want to ride it !!

[Matt Hale]

Image of red pickup showing outer face resin

D652AC0B-89DB-4E3D-9DAA-9984F606D29D.jpeg (129.99 KiB) Viewed 5467 times

I hope you can see the image of my red pickup here. I wonder if you can say it looks fine or is it impossible to tell? I understand it may be impossible to see cracks here but I can’t see any in real life…just thought I’d try you guys some more! I’ve removed the outer cable protection sleeve and checked the wires. Soldering is good on the pickup. Wire not brittle.
Thanks in advance.
If anyone can rebuild/mend these then I am up for a try depending a little on cost as new one from Italy is about £200 I think…

[George 350]

Hi Matt,
I have a spare pickup and magnet that was OK when I last had it fitted. It's not for sale as it is my spare one, but PM me your address and I can post it to you to try out if you would like to.
There may well be other members not a million miles from you who could assist you as well.
If yours does turn out to be faulty, then George Lane used to repair them, maybe still does. His details appear in A Tutto Gas every month.

Regards,
George Farenden

[Matt Hale]

9E18705D-3DAE-4ED0-B0FA-B2F79BD75402.jpeg (198.29 KiB) Viewed 5438 times

Hi George- many thanks for you very generous offer. Before I take it up can you look at this image. The brown section within the magnetic yellow metal appears a bit damaged. It isn’t magnetic but yellow metal is.
Is the damage possibly a problem? What does that brown ring do as not magnetic it seems…
Thanks - Matt

[mbmm350s]

Hi Matt,

We have no idea if the pickup is at fault or not, even if there is a crack, I would take up George's kind offer of one to try first.
Only if that helps consider the replacement or repair options.
You need also to check the transducers, one may have a fault.

The damage on the outside of the rotor is minor and so long as the clearance to the pickup is fine then i wouldn't worry.
Always fit the rotor and check that the clearance is equal all round. I notice that incorrect washers have been used in the past, this can distort the pickup units housing. Any nicks in the rotor can be filed out.
The purple part is the magnet. The whole assembly should be tight, meaning you shouldn't be able to rotate either outer part independently.

Cheers
Mark

[Matt Hale]

Hi Mark - thanks again….I put on new blue transducers. I wasn’t sure I needed todo this so have old ones still. See pic here of the ones I put on:- Ducati energia… number 32398112 then also nos. 21. 02
Maybe these are the problem and getting hot? Earthed ok I think…the pick up isn’t connected here but goes on red I believe!

604F8DB8-6175-4973-9F87-53C30F6850BC.jpeg (23.6 KiB) Viewed 5368 times

[mbmm350s]

Hi Matt,

Before you ride with the blue transducer you must adjust the timing. This is because the scooter transducer will have too much advance. Please check the timing with a strobe gun ANT 1 should be aligned at 6000 rpm with a mark on the crankcase, exactly where the mark is depends but since yours was an electric start it should be at 12 o clock.

The yellow of the transducer needs to be extended and earthed to the chassis at the headstock. The white is also earth and would be connected to an earth wire from the stator if you have it, if not, it is not necessary to connect it if you connect the yellow.
The yellow earth is on the high energy side of the transducer, the white is on the control side, whilst they are electrically connected, if you use the white alone there is a risk of interference and erratic timing.

To re-iterate please don't ride with blue transducer until the timing is set correctly.
The red is connection to pickup.

Since there is no tachometer output on the blue transducers you will need a strobe to display rpm if you don't have a mech tacho.

New upgraded transducers with tachometer output and with no need for big adjustment in timing can be sourced from Alex Luzzi in Siena. For these conveniences you will pay more than for the basic scooter transducers.

Mark

[Matt Hale]

Hi Mark
The is very helpful- sincere thanks. I didn't realise the timing would be advanced on these blue boxes.
I'll need to get a strobe that shows RPM as you say. I have earthed yellow wires to headstock already and not using white.
Thanks again and I'll let you know how I get on. Hope I can get a strobe displaying the RPM!
Matt

[Matt Hale]

Hi All- After much assistance on this thread for which I am v grateful I have sorted a few things on my 350 1978 electric start (missing) MM.

I just got around to checking the timing using a strobe light. I found it was set correctly EXCEPT the mark seemed to move or 'wobble' around the vertical position... What I mean is that when the strobe light flashed the ANT 1 mark was in correct place at top/ on vertical except it didn't appear static. It moved constantly a little to left and then to right. Never just static where it should be- in my bike's case at top seen through the hole in the casing usually filled by a rubber bung.
This is all happening at a pretty steady 6,000rpm but its not easy to keep it bang on 6,000rpm so slight variation in that figure. Does that cause the 'wobble' in the ANT mark and therefore normal for some movement ? There is also a little. misfiring occuring at constant 6,000rpm.

Does this indicate a pickup issue- ie: my red plastic pickup and magnet are faulty or touching perhaps? Should I expect the mark to appear static?

I have been kindly offered another red pickup to try but I'm cautious about taking this offer up as I don't want to damage someone else's valuable electric component... please correct any of my misunderstandings and all ideas welcome!