125 WITH NO SPARK

Lambertini era singles (125 and 250 - half v-twins)
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72degrees
Posts: 1549
Joined: 31 Aug 2007 21:24
Location: West Midlands

Re: 125 WITH NO SPARK

Post by 72degrees »

Nil desperandum!

Substitution with 'known good' components is sometimes the only way to diagnose something. I've lent a working twin cylinder pickup to a couple of people that proved that was the issue though their unit looked fine.

Not many 125 Hs around in the UK though as you say. I nearly bought one off evguru for my lad to use for 'racing' ;) May have dodged a bullet.

Beer is good, but I find a decent Italian red plonk more efficacious in this weather.
125H
Posts: 98
Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

It may well be, but its easy to collect lots of useful or useless ornaments in the form of components that did not cure the problem.

The 125H was never officially imported into the UK so knowledge and spare parts is rare I made a rookie mistake when I bought mine, the sump was full of oily sludge and the fuel tank with the remains of old lawnmower fuel. Instead of draining it all down and trying to start it I embarked on a restoration project, if I had done some research and tested the engine it would have been back on the auction site before the restoration was started.
So I now have a very pretty Italian lightweight that does not run as it should and having just about exhausted all expert advise and spent a load of cash on testing only to be told what I already knew its difficult to know where to go from here. I have a few last ditch things to try but am not hopeful unless I can find a complete new system that will fit. There are options of course involving some quite serious and expensive conversation to a modern adjustable advance system but it would probably require machining of a new rotor to fit the crankshaft and how much money is it worth throwing at a 125H.

I would agree about the Italian red plonk, I have a nice Chianti warming by the fire.
Ian_C
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Location: Hastings, East Susse
Location: South Coast, East Sussex, Uk

Re: 125 WITH NO SPARK

Post by Ian_C »

I used Google Lens on a smart phone to translate the article https://www.motomoriniclub.nl/zuendung.pdf to English and I can see that this gives a good description of the importance of the 1.38V trigger point voltage and how it occurs earlier as engine rpm increases. You can use Google Lens to give a voice-over description too. I quite fancy a 125H but the problems you guys are having has put me off a bit. Ian
1974 350 Strada
1975 350 Strada
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125H
Posts: 98
Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

The 125H problem is not just within the UK I have made quite a few contacts in Germany and the Netherlands with very similar issues, although some owners have no problems at all with them.

One German contact is looking at using a modern Ducati single ignition/generator unit and I await with some interest as to how he gets on with that. Personally I have wasted time and money having my ignition tested by so called experts with no result, so yes you probably did miss a bullet by not buying into one, although I doubt very much that Paul would sell you a crap bike that did not run, its not worth his reputation.

Personally I think the problem may be one of assembly that is to say setting the static or base timing, according to the Germans this is achieved by setting the piston at TDC on the compression stroke both vales closed PMS mark aligned with crankcase mark, then turn the engine back to the ANT mark or A mark in the case of an early bike. Hold that position and then move the stator plate to align the two scribe marks on the rotor with the two lines on the black pick up, the engine should then run - hopefully! Final adjustment is made with a strobe light. I did a quick check with a timing disc and this appears to give 32 degrees BTDC. This is of course in theory, problems may exist in the pick up not aligning with the two magnetic triggers in the rotor, I was told that sometimes if a non - standard pickup was fitted that it may require shimming to get the right switching for advance, again more theory. My 125H is under wraps its too cold for an old bugger like me to be out in the garage, but once things warm up I am certainly going to look at the static timing to see if it will run, if not more investigation will be required.

Regards
Leonard.
julianharty
Posts: 542
Joined: 15 May 2016 16:34
Location: High Wycombe
Location: High Wycombe Area (Bucks)

Re: 125 WITH NO SPARK

Post by julianharty »

Some suggestions:
  • I've just bought what's probably a 125T in pieces. Perhaps we could use it to help diagnose the cause(s) of the issues you've found
For the bike I've bought, the engine was running when the bike was dismantled in 2016 and is complete. I also have the transducer, carburettor, etc.

I'm near High Wycombe, Bucks. so 2 hours from Loughborough. Happy to do what I can to help get 125's in good working order.

Julian Harty
125H
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Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

Hi Julian,

There are 125H problems all over the place, as you can see from this forum.

I have done very little with mine over the winter but just getting back to it now, mine is an early model and the electrics on the later bikes are slightly different.

No one seems to know what the problem is, I thought it maybe crankshaft related but I have replaced all the bearings so movement there should not effect the timing. Personally I feel its a problem within the stator and its relation to the transducer, pick - up and magnetic triggers in the flywheel, I spent quite sometime getting these items lined up with shims but to know avail. The ignition system is probably a 'knock off' from a two stroke scooter done on the cheap by the factory. To that end I have an electrical engineer looking at fitting a 4 - stroke programmable transducer with some other modifications that I don't quite understand. I am a points and magneto man and all this leaves me cold. Be careful of spending money on this ignition project, to date I have wasted about £200 paying so called experts to test and repair the system only to be told it does not advance - something I knew already. I hope the current man can come up with an answer and if so will post the findings.

Also I would mark the ignition timing as is before you disassemble it, there is also a base setting that does not seem to appear in any of the manuals it involves setting the piston at TDC on the firing stroke with both valves closed, the PMS mark on the flywheel should then be aligned with the timing mark at 12 o'clock on the crankcase, then move the flywheel to the ANT mark, at this point the two fine scribe lines on the flywheel should align with the two lines on the pick - up you can see this through the slot in the flywheel, if not move the stator until they do, any final adjustment is made with a strobe light once the engine is running - good look with that! The ignition has two fixed settings controlled by the flywheel one for starting and tick over (with no kickback) and it should then advance to normal running at about 2000 revs, however mine will not make the jump to advance, it is a jump and not a gradual increase like the V twins which are different. Running the engine in this retarded state will cause overheating and sluggish performance, I do not know why Morini opted for this ignition system probably cheapness and availability its clearly for a two stoke and two strokes tend to run retarded anyway so that may be the root cause.

Regards
Leonard.
125H
Posts: 98
Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

Hello All with a 125H as you may know some of us have experienced ignition problems with the 125H I appear to have recently resolved mine with the help of an electronics expert. Its now finally running as it should, initially I used shims to make sure that the pick - up was in line with the magnetic triggers inside the flywheel mine was not and used three shims. However the problem was not cured. I then got in touch with Mr Anthony Tambs who runs Scootronics in Stafford. He put my stator and flywheel onto his test rig and the oscilloscope indicated no advance as before and as found by other so called experts. However Mr Tambs was able to identify the problem it was one of polarity it appears that the pick up or its wiring may have been replaced wrongly and after a temporary fix to the wiring the oscilloscope was indicating the timing was in fact now advancing and later refitting to the engine proved it now works.

Mr Tambs also makes his own range of pick ups and transducers which I shall be fitting to my Morini.

If anyone still has a problem give him a call on 07971 475134 or email anthony.tambs@gmail.com his website is called Scootronics.

He is a real Gentleman, Now I am not guaranteeing that his fix will work with all 125H's but it did with mine so its perhaps worth giving it a go.

Regards
Leonard.
julianharty
Posts: 542
Joined: 15 May 2016 16:34
Location: High Wycombe
Location: High Wycombe Area (Bucks)

Re: 125 WITH NO SPARK

Post by julianharty »

Leonard,
Thank you for the detailed resolution and for the contact details which will help others in future.
What's left for you to do before you can ride your 125 reliably?

Julian
125H
Posts: 98
Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

Hello Julian,

now I have the engine running I have to attend to just a few items that were put on the back burner until that was the case. I arrived at a point where I was not going to spend any more cash or time until the engine worked and it almost went back on eBay!
So I have to fix a small leak in the petrol tank which I will have done professionally and I am still working on the footrests, brake and gear lever. The originals did not come with the bike and a previous owner had fitted rear sets which did not work too well so I am currently modifying them which is not easy as no one makes a set for a 125H.

I would hope to get it all done by mid June or early July and the engine will then require some running in as I did a complete rebuild on that including a new piston and re - bore.

If I get it done earlier will let you know, my advice to anyone buying a 125H or indeed a Morini is to make sure it runs before you part with any cash as I rather fancy that there is a lot of rubbish out there and you may end up with a saga like mine, I made that rookie mistake and remain wise after the event. If it runs alright then you will probably be OK the main problem seems to be retarded ignition which will cause over heating and in time the engine will lose power, until it cools again. The ignition can be checked and adjusted and the importance of polarity of the pick up is clear and the alignment of the triggers and pick up which I have previously described. Why these things change remains a mystery, perhaps the wrong parts where fitted or a wire that came off was not put back correctly or the laminating that supports the pick up may have compressed over time but that's all conjecture.

A word of caution! Pick your expert, there are a lot of them about who do not know what they are talking about in connection with Morini's it had taken me a long time to find Anthony Tams but he is a real expert with electronics.

Regards
Leonard.
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themoudie
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Location: Perthshire

Re: 125 WITH NO SPARK

Post by themoudie »

Aye Leonard,

After my having received my whole ignition system back from Tony (Scootronics) last September 2022 and the ignition advance problem remaining unresolved, the bike was shunted to the back of the workshop and a cover drawn over the whole debacle! :evil:

Today, quite on the spur of the moment, I thought that I would see if anybody had made any "Eureka!" findings and read, with delight that your 125H now appeared to be a running machine. Is this still the case?

I have spoken to Tony, today and he is willing to have my stator and to make the necessary changes, in the hope that it will be as successful as yours apparently was.

"Sending the negative signal, before the positive from the coil" is all Greek to me, but if it works and yours continues to be performing well, then I would like my polarity reversed as well. :D

I hope that you have been able to enjoy riding the 125H this year, rather than watching it fester under a cover.

Good health, BillR
125H
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Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

Hello Bill,

Long time no speak, but yes my engine is running OK it advances at about 1200 rpm and I am sure it will rev to maximum if I let it, but its being run in for the time being.

Unfortunately, this year has been a mess due to two family bereavements and all the associated problems of getting probate and sorting out various matters associated, so I have had little time for riding and its not been a good summer anyway. I took it for a buzz around the block yesterday and think I need to attend to the wheel alignment and possibly the front forks now that its bedding down a bit, but that's only a minor issue compared with the engine/ignition problems I have had. I am surprised Scootronics did not reverse the polarity on your ignition, but I suppose having me looking over his shoulder and wanting a result perhaps spurred him on rather that getting something in the post. I have fitted one of his own high power transducers and that seems to have improved starting - good spark.

I had my stator plate rewound and still wonder if they set the polarity for a two stroke, two strokes run regarded and possibly they did not realise it was a four stroke engine I think the ignition system was made for two stroke scooters and that sort of thing and fitted up by Morini - probably on the cheap.

I hope Scootronics can do the same for you and will be very interested to hear if it sorts the problem with your 125H they do seem very temperamental, mine does not tick over too well but am told by a contact in Holland that its quite normal, you have to keep blipping the throttle at traffic lights!

Well I will sign off now, please let me know how you get on with it.

Regards
Leonard.
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themoudie
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Re: 125 WITH NO SPARK

Post by themoudie »

Aye Leonard,

Thank you for your quick reply. I am sorry to read of your two family bereavments and well aware of the resulting glut of formalities to be completed in triplicate.

Having spoken with Tony today, it wasn't until he had done some research before your arrival that he thought polarity might be an issue. He saw my components in September 2022. Then, had been in dock for a quadruple by-pass from February 2023 until the end of March 2023. He is still on "light duties"! I didn't have my stator plate rewound. But, replaced my CDI power coil, with an aftermarket "Lambretta" item, probably Indian in origin. I did re-connect the replacement coil to the CDI wires to the same terminals as those originally used. BUT ......! Didn't check the coil polarity and in my defence, I haven't a clue about electrickery and don't understand how a negative pulse signal, before a positive pulse signal can be generated from a coil, or how that affects the CDI circuitry. Very much "Smoke and Mirrors", as I am wired for objective and not algebraic theorising.

I am despatching my stator and associated bits off to Tony tomorrow for re-assessment on his rig and oscilloscope to see if I too have a polarity problem.

Again, my thanks for posting your outcomes and I hope that you enjoy running the wee beastie. The Minx always ticked over no problem, maybe a bit fast when compared with a long stroke single, but a steady 1,100 - 1,200rpm was no problem. Also yours being newly rebuilt, will need at least a 1,000 miles to bed in and free off, so I wouldn't worry too much at present. Just make sure to change the oil after 100 miles at most and then again after 500 miles, before using your preferred oil and changing every 1,500 miles. Nora Battie's stocking in the sump doesn't filter much! :wink:

Good health, BillR
125H
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Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

Hello Bill,

thanks for your reply, I hope Tony can sort it out for you, he is an electronics expert not the usual auto electrician and I think if it wasn't for him my 125H would be back on eBay by now - parts only!

I am no electronics expert at all and have no understanding of what Tony does he is the expert. In regard of tick over a regarded engine will normally tick over much better than an advanced one and like mine was, yours is probably running with too much retard good for starting and tick over but not much else. If retarded the engine will over heat lose power and probably stop. That's for four stokes of course, two strokes run retarded, hence my suspicions about this ignition system being used on both types and the pick up being incorrectly wired in. Tony makes a CDI's for two strokes and also four strokes. I did try a German CDI which worked very well, think it was BGM but in the end fitted one of Tony's units which works really well, good fat spark! If you did not have the stator rewound, its always possible that someone else put the pick up wires the wrong way around, the engine does not run so they then sell the bike, these things are around 40 years old so anything can happen to a loose wire over that time.

In regard of running in that may have to wait until the spring now as I will not risk my old bones to winter riding and all my new chrome and polished alloy, but I do take your point on oil changes. I have also fitted a magnetic sump plug to collected any metal elements from the engine oil. I tend to use Castrol Classic 20W/50 and after running in will change it every 500 miles. There are those out there who say supermarket oil is good enough but good oil is still cheaper than a new engine.

Just as a note, when you put it together, start at TDC on the compression stroke, then turn the flywheel back to the ANT mark, at that point the two small scribe marks on the flywheel should line up with the two lines on the pickup, if not move the back plate until they do. That's the base static setting and the engine should run, you can then set the timing more accurately with a strobe light. I also had to shim my pickup so the contacts on top aligned with the two magnetic triggers inside the flywheel the shims are made by BGM and I bought mine from Beedspeed. Its a bit of a faff put if you make two mark on the side of the pick up in line with the contacts and mark the triggers with white chalk you can then see through the slots in the flywheel as to if the triggers and pick up are in line from memory I had to use two shim's. I can only assume if it was shimmed originally, then they had been lost over the years or missed out be someone who did not understand the ignition system, or perhaps do to age something had changed a bit.

Please let me know how it works out, there are 125H's out there that run fine and there are many like ours that have had problems.

Regards
Leonard.
125H
Posts: 98
Joined: 30 May 2018 18:36
Location: Loughborough UK

Re: 125 WITH NO SPARK

Post by 125H »

Hello Bill,

just thought I would touch baser, did you ever sort your 125H problem?

Regards
Leonard.
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