Galletto ignition

[andy-gadget]

Hi brains trust, a magneto question.
I am currently doing battle with my '50, 160CC Galletto.


Trying to get it going for this coming weekend, which is the main old bike show in my home state of Tasmania, the Ross motorcycle show.


After rewiring the headlight and finding a wiring diagram that reflected reality.



Getting the MA18 Dellorto carby to keep the fuel on the inside, I am on the last bit, and I have no spark.

Anybody gone down the Galletto rabbit hole before?

[SED]

Did it have spark before the rewire?  If so, it suggests a coil ignition. 

Manuals available here (you probably know this!) http://www.rpw.it/Documentazione.htm

This document suggests (to my feeble Italian) a flywheel magneto, which means it is probably a bad connection in the spark plug lead or (more likely if it has been sitting) needs the capacitor replaced: http://www.rpw.it/Files/Guzzi_Galletto160_UEM.pdf

Cool bike - let us know what you find!

[andy-gadget]

Thanks SED, the second most left hand black wire (m) is the shorting wire from the low tension side of the magneto, and is shorted to earth by the nail type switch at the top when the switch is in the out or key removed position, it connects the negative (bike is negative earth, another bit of information that took some finding) of the battery to the vehicle earth when in the inward position, allowing the horn and other electrical items to work. The headlight has a seperate supply from the flywheel dynamo, so no headlight unless the engine is running.

BTW I don't know if it has spark before, so the detective work starts from here, my first step will be to check the low tension side of the magneto for shorts to earth, then change the high tension lead. Rule number one of fault finding is "Change only one thing at a time".

Given the state of the original wiring, I didn't want to power anything up until it was sorted, as Carello metric wiring smoke is hard to find, and I am assured that Lucas imperial wiring smoke is the wrong polarity

The points.

[Kiwi_Roy]

It looks like it would run without the battery, I don't think it does anything for the spark.
Make sure the points make contact when they close (zero resistance) and you can measure some resistance across them when open (not shorted by other wiring)

[Bill Owens]

andy,

I have a question and a comment . First, watch your knee on that coil, and where would I look for a VIN number on a Galletto?

   Thanks

[SED]

Roy is the master of electrics - so I'm a little uncertain here...  but I think that the test Roy suggests is just the low tension coil of the magneto.  Low tension resistance in the larger Marelli mag is low - about 0.7 Ohms. To test the high tension coil check Ohms between the plug wire (or its socket) and ground - this is close to 5,000 Ohms on the larger Marelli. 

That red wire looks to be from an automotive style capacitor - cheap and easy to replace (if you can get behind the flywheel!).  Capacitors degrade with time so can easily be a cause of a weak spark. 

[n3303j]

 The points in the picture look like the contacts are heavily oxidized. My snow blower  (flywheel magneto) got used about once a year. It wouldn't  start first time next year because points built up a non conductive oxide layer. This layer did not come off easily. It would look clean after dragging 600 wet/dry through the contacts but they didn't conduct electricity. Took about 5 minutes with the paper before the points once again conducted electricity. Must check with an ohmmeter.

Also disconnect the grounding shutoff wire just in case it is inadvertently grounded in a hidden spot. Disconnect all point wiring and assure yourself with an ohmmeter that there is infinite resistance between frame ground and the movable contact arm with the points open. Sometimes the insulatong washers on the coil terminal get sorted wrongly and the stud becomes grounded to the point frame and frame ground.

Original BMW /2 magneto coils failed because of age and would either short out or become discontinuous. Ohmmeter between coil wire to points and non resistor spark plug lead should show infinite ohms. I forget exact numbers but BMW primary was less than ohm. Secondary was about 11,000 ohms.

[SED]

Disconnect all point wiring and assure yourself with an ohmmeter that there is infinite resistance between frame ground and the movable contact arm with the points open. Sometimes the insulatong washers on the coil terminal get sorted wrongly and the stud becomes grounded to the point frame and frame ground.

In my (limited) experience with stand-alone magnetos (not flywheel type) the low tension coil is grounded on one end and connected to the movable point on the other which gives a reading of about 0.7 Ohms (with the capacitor disconnected).  I think Andy will see low Ohms, but if no resistance then the points are likely grounded as you suggest.

BTW Andy what is that cool sloper single at the show (do I read Triumph?)?  And a Matchless Silver Arrow behind?   Rare machines!

[andy-gadget]

BTW Andy what is that cool sloper single at the show (do I read Triumph?)?  And a Matchless Silver Arrow behind?   Rare machines!

The sloper is one of my bikes, a '33 Triumph Silent Scout 500, model B, only 250 made, mostly sold in Canada and Australia, mine came from South Australia.
The Silver Arrow won best in show two years ago, justifiably, it was immaculate.

Tasmania has a very strong old bike culture, it is amazing what comes out of obscure sheds and are ridden regularly, my around town bike is a '52 Matchless G80S.

Here is a link to to my photos from two years ago, https://andy-gadget.smugmug.com/Motorcycles/Ross-2016/

[andy-gadget]

It lives.............b ut not very well

I spent the time from my first post rewiring the headlight, as I didn't want to power anything up in there until it wasn't one mass of potential shorts.

Not as neat as I want, will acquire some smaller terminal strips and redo it when I return from work.

So battery installed, park working, no loss of smoke, so on with the diagnosis.

I measured to resistance from the inside of the plug cap to earth, infinity, the resistance of the high tension coil to earth should have seen on the meter.

Pulled the flywheel end of the hi tension lead and measured the inside of the plug cap to the flywheel end of the lead, infinity, removed the plug cap, resistance across the cap, infinity, measured the lead, zero ohms, smoking gun

Definitely wired as a flywheel magneto, so low tension circuit is points switching to earth, same circuit on a "normal" magneto is an internal loop in the rotor assembly, and so requires special equipment to measure when the points open (inductance measuring black box).
The points looked grungy, but even before cleaning them they measured fine.

All the plug caps I had on hand are for airhead BMW's of Guzzi's, short right angle caps, could have been made to fit, but why not do it correctly

Wondered over to North Hobart to see JK Rowling's latest movie ( I am off to work for two months on Thursday, no new movies then) and came home via the local bike shop, and acquired the correct 5K ohm, long, 45 degree cap.

Test kick, spark, but a bit weak. Key out, no spark, so everything in the headlight was now working as it should.

Cleaned everything up and took it off the work stand. With the chemical assistance of ether based "Start ya bastard (Aussie product just in case you couldn't tell)" and after playing with ignition advance and throttle position it started.
No horrible noises or fountains of oil or fuel, so good so far.
But it didn't run well, wouldn't run at all with the ignition at full retard, as my future is a full service of the timing side to make sure it is as it should be.

BTW I had filled and primed the oil system as part of rewiring the headlight, ran the motor from the flywheel nut with a drill until the return oil pipe at the filler cap flowed well. The same with the fuel system, this being a very early Galletto it has the fuel tap next to the filler cap, this was done away with on the 192cc version. But it took a day or so for the (I assume) cork fuel tap to wet up again and start sealing.

Decided to give it a rest and come up and update the post.

Again, thanks to all who made suggestions, all were appreciated and acted on.

[andy-gadget]

Further to this whole thread, has anybody ever removed the flywheel retaining nut on a Galletto?

The flywheel turns clockwise viewed from the left side of the bike, so all fitting rules say it should be a left hand thread, but being a closed cap nut, which means the thread isn't visible, so I can't confirm this.


Nowhere in the manuals that I can find on line, is the hand of the thread mentioned, just the puller required.

This is different to all the other external flywheel Guzzi's as they all have a left hand thread lock nut on a right hand thread crank shaft thread, but the flywheel still turns clockwise, so the rotation locks the lock nut down further. The lack of a lock nut is the difference, the rotation should lock the single nut down further, the problem is am I correct in this assumption.



I don't want to hammer away at the nut and only be tightening it, as the logical extreme of this is not something I want to explore

[SED]

Cool Triumph Andy!  What an interesting Triumph - built right about the time Ariel bought them!      (a 1947 Ariel is my go-to bike - similar to your G80 https://youtu.be/3sm8UXQsckY)  An amazing diversity of old and interesting motorcycles in your neighborhood!  Thanks for the pictures.

It looks like you know your way around magnetos so probably nothing I can do to help with it or the wiring.  Rewired the bacon slicer including making myself a wiring diagram to sort it out. It's in the bacon slicer thread in the projects folder or I can send it to you. 

I don't know about the flywheel nut either, but your picture shows a hint that the flywheel is internally threaded similar to the larger Guzzi flywheels.  Any chance that thread direction is a clue?

Love the Galleto.  Is the Nuovo Falcone yours too?

 

[andy-gadget]

Even though it wasn't running, the Galletto won best European at the Ross Motorcycle show, very happy

[Demar]

It looks like the center of the flywheel has internal threads that the puller grabs onto. The flywheel might be pressed on and the puller is used to pull it off. Check to see if your flywheel has internal threads around the hole. See attached picture. I'm not sure about this or the threads of the visible cap nut. I recommend you ask Charlie Mullendore as he has rebuilt a Galletto engine. It looks like the flywheel puller is #22 in the attache photo of special tools. I've also included a wiring diagram for the 160. I hope this helps.

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[Kiwi_Roy]

Test kick, spark, but a bit weak. Key out, no spark, so everything in the headlight was now working as it should.

But it didn't run well, wouldn't run at all with the ignition at full retard, as my future is a full service of the timing side to make sure it is as it should be.
 

Is it possible to change the relationship of the coil to the magnet at the point where the points open, maybe the field is too weak at full retard when the points open.
The field might also have become too weak while it has been apart without the coil to act as a keeper.

[andy-gadget]

Italian engineering 1, Fitting rules of thumb 0.

The flywheel nut on a Galletto is M14 x 1.25 MM, RH.


The puller thread is fairly certain to be M33 1.5 mm, RH.
This should be the same as the flywheel puller for my Bultaco Sherpa T 350, model 92. This is unfortunaly buryied in my sh1t as I am not currently working on this bike, but will be shortly, so finding it is now a priority. BTW in line with the mirror image sh1t going on with Bultaco's and Montessa's the puller for my Montessa Cota 348 is M33 x 1.5 mm, LH.