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Discussion Starter #1
I have just re-commissioned the 1972 T100R I restored last year. At that time it had a new loom, a Boyer Mk 4 system, one new coil, a 'Lucas' reg/rec (single phase) and a new Yuasa 9.5Ah lead acid battery. It also has LED headlight, pilot light and tail light (and 2 new Premier carbs). I did nearly 600 miles on it last summer with no issues at all.

Gave it new oils and a thorough check over at the weekend. Started easily on its new carbs. 14.5V when running at the battery, so presumably the alternator is working. No obvious issues, everything working.

Did a 3 mile loop near home, all well. Came home, looked for leaks etc, none. Lights good. Went out again.

3 miles down the road and a sudden loss of engine. No coughing, no warnings, nothing. I was running with the LED pilot light only. Just coasted to the side of the road. Petrol OK in the filter to the carbs. Lights work, electrics all OK it seems. Just no ignition. Recovered to home.

On checking, battery seemed a bit lower than I'd expect, around 12V, but lights all worked.

Thoroughly charged the battery (and I've now bought a new one anyway) and I had a spark at the plug. Could not find any wiring fault, coils seem to have the resistances they should have (or thereabouts). No fuses blown. Everything all clean and tidy. Nothing obviously loose.

I'm suspecting a poor battery - I will admit to not having charged it over the winter until just before I wanted to use it (so it was unused for about 4-5 months), and having now recovered the sparks at the plugs, it does seem to lose voltage quickly when the headlight is on. After charging the battery to 12.6V, it dies to about 12.2V with the LED headlight on after only a minute or 2, but recovers to about 12.5V when the light is switched off.

My question is though, given that the alternator is producing 14.5V at the battery, how can a poor battery cause an ignition problem given that it was good enough to start in the first place? If the alternator is producing even 50% of its 120W, that would be say 5A, which should be enough to run the ignition system.

I'm also looking suspiciously at the alternator - even though it's producing electrons at 14.5V, maybe it's not producing enough of them to maintain the battery charge? Any suggestions anyone?
 

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Hi Andy, You can't test charging system with bad battery. It can suck all the power into itself, but give none/little out.

If you really want to test charging system you need to start with a known good battery with full charge.

To test your alternator you can purchase 100w 1 ohm resistor & make a charging tester. That is the factory way. If you follow the shop manual to the end it will test every component of charging system. You'll need ammeter also. As well as Volt/ohm meter that can read properly with motor running. You will find shop manual insists on installing a known good, fully charged battery before testing. That is a must. Following the tests really does work. Once you are set up, not very hard to do. Very fun to see how the system works.

Remember any number of faults can effect spark. Be sure to test power & ground at Boyer connectors & compare to battery voltage. You could have several problems going on at once. Volt drop in ignition switch, fuse, connectors, wiring is common problems.

I don't know what you have available in UK, but in USA very hard to beat Motobatt battery. MB9U is size I use. They have very good power, take a charge a little more quickly especially in stop/go traffic & keep their voltage a longer time when bike is not in use. I feel they are worth the extra cost.
Don
 

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Discussion Starter #3
Hi Don,

Many thx for the response. I later tried it with the new battery, just off a full charge. It runs just fine. I've ordered a 100W 1 ohm resistor (and a new multimeter as mine is years old and getting a bit tired) and I'll have a go at the WM method of testing.

I'd already checked the voltages at various points on the loom and couldn't find anything suspicious, and it's all new anyway, and the ignition switch - not that that's any guarantee. I also waggled all the wiring with the engine running, and again, nothing found. So I'm still suspecting the old battery. Which did eventually get to the point where the smart charger shut down, so maybe I've recovered it a bit.

In advance of the testing parts arriving I'll ride it around my local loop on its new battery (near enough to push it home - or at least walk home and fetch a fresh battery!) and check the battery voltage over a few rides. If the alternator can't keep up with the rate of current draw then that's a clue as to the state of the charging system too.
 

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I'm about to embark on testing the alternator on my T100R, as recommended by Don. Had a good search of the forum to get more guidance, and found this.


Looks fairly simple to understand - even if I did do physics at A level and 1st year Uni! That was a very long time ago.....
 

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Thanks for this, it's a good read. Someone once said " if you can't explain it simply, you don't understand it". That's a helpful write-up.
 

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Hi Andy, Rick,

Regrettably, much of it is logical cobblers - Stator studs/Rotor and stator position 70 TR6P, post #31 ...

For your '71-on bikes:-

Remove the center Brown/blue wire from the rectifier. Connect the ammeter in series with the rectifier and the brown/blue wire that was plugged on to that terminal. Start the bike. The ammeter should show a discharge of 1-2 amps at idle speed. The needle should move to charge as you increase engine RPM to 2000 rpm. The needle should show a charge of 1-2 amps at 2200 rpm. Now switch the lights on. There should dip in charge rate followed by moving back to positive above 2200 RPM.
... is a major :oops: It's basically and fundamentally wrong.

You know the rectifier consists of four diodes and a specific property of diodes is current can only pass through the diode in ONE direction? For an Ammeter connected "in series with the rectifier and the brown/blue wire" to "show a discharge of 1-2 amps at idle speed" and then "move to charge as you increase engine RPM to 2000 rpm.", current would have to pass through the rectifier diodes in both ("discharge" and "charge") directions ... :oops: If it does, the rectifier is donald.

An Ammeter can only show the above or similar if it's connected in the Brown/Blue wire between rectifier and battery terminal. Risking telling you things you know already, reasons are:-

. Lucas motorcycle alternators (like most motorcycle alternators) are "permanent magnet" because the rotor is essentially permanently-magnetised. Electricity and magnetism are inextricably linked - if you pass an electric current through a piece of metal, the piece of metal will have a magnetic field around it; more particularly for permanent-magnet alternators, if you wave any magnet near a piece of metal, the magnetism induces an electric current in the piece of metal.

. Therefore, once you start a permanent-magnet alternator rotor spinning, the alternator is generating AC (this does require an electrical 'load' across the alternator stator, the bike's DC electrics connected through the rectifier are "an electrical 'load'").

. Permanent-magnet alternators generate more only the faster the rotor's spun - that's why 'original Lucas' rated theirs "x Amps @ 5,000 rpm". However, the relationship between rpm and generated Amps isn't linear - that's why 'original Lucas' advertised "75% of rated @ 2,400 rpm" for the single-phase RM21 and RM23.

. Therefore, @ tickover rpm, while a Lucas alternator doesn't generate very much, it does generate something - were an expensive high-end Ammeter connected in series between the rectifier's DC output and Brown/Blue wire, the meter would show the small tickover DC output ("charge") from the alternator/rectifier.

. This small tickover DC output from the alternator/rectifier is less than, say, the ~3.5A drawn by the ignition coils. Therefore, @ tickover rpm, (most of) this ~3.5A is still drawn from the battery; an Ammeter in the Brown/Blue wire between rectifier and battery terminal will "show a discharge of 1-2 amps at idle speed" from the battery. (y)

. As engine rpm is increased, the alternator generates more. So less is drawn from the battery to supply the consumers (ignition coils, lamp filaments, etc.); "the needle" of an Ammeter in the Brown/Blue wire between rectifier and battery terminal "should move" first to show less discharge (from the battery) and then "to charge [into the battery] as you increase engine RPM". (y)

. An Ammeter in the Brown/Blue wire between rectifier and battery terminal will only show a "charge" into the battery when the alternator rotor is being spun fast enough that the alternator generates enough to supply all the other 'consumers' in use first. That's why, engine running, lights off, when the lights are switched on, "There should dip in charge rate followed by moving back to positive", when the engine rpm are increased enough to spin the alternator rotor fast enough that the alternator generates the extra consumed by the lights. (y)

To summarise:-

. An Ammeter connected as suggested on that JRC webpage - between a rectifier's DC output terminal and the Brown/Blue wire - cannot indicate a "discharge" (from another source like the battery) unless the rectifier itself is faulty.

. Otoh, an Ammeter connected between battery and rectifier can indicate both "discharge" (from the battery) and "charge" (from the rectifier into the battery).

Also Emgo and Lucas offer replacement Rotors and stators that have proven reliable in service. In addition These companies have taken advantage of modern components to offer 180 watt units to replace the 120W Lucas components.
Also nonsense.

'Original Lucas' always offered higher-output versions of alternators as long as British motorcycle makers made special versions for particularly the police; I've a copy of a rpm/Amps graph from the Lucas Archive at the British Motor Museum of a version of the 1960's (i.e. "modern" over half-a-century ago :rolleyes:) 3-wire single-phase (RM19/RM20) producing ~15A @ 5,000 rpm ...

The original "10 amp" ("120W") stator on your bike was a RM21, which Lucas first produced around 1969; the identical-looking RM23 stator was "180 watt" (14.5 Amps @ 5,000 rpm). While neither Triumph nor BSA did, Norton offered the RM23 as an option on 'civvy' Commandos and fitted it as standard to the '75 Mk.3 850 with electric-start.

When 'original Lucas' superseded the RM21 and RM23 single-phase stators with the RM24 3-phase during 1978, both "120W" (aka "low output") and "180W" (aka "high output") versions were made (my T160's have both had the latter since 1982/3, nothing to do with either Emgo or 'Wassell Lucas' :cool:). The Co-op fitted the low-output 3-phase as standard '79-on to kickstart bikes, the high-output was available as an option and fitted as standard to electric-start bikes.

Btw, nothing to do with Emgo or 'Wassell Lucas', a British company also makes alternator components (arguably not 'pattern' as the company could show a connection to 'original Lucas' in GB :D). 'Wassell Lucas' prohibits the maker or retailers from mentioning "Lucas" either on the components or in listings, so they're known/listed simply as "Made In England" or "Made In UK" ...
Hth.

Regards,
 

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Discussion Starter #7
Hi Stuart, Hth? It does, thx. I appreciated that that link applies to the conventional Triumph installation, and I have EI and an electronic reg/rec, so it's not directly comparable. I was not sure how to connect the 1 ohm load to the alternator to check the voltage output - but it does show the wiring diagram - so when the resistor arrives I'll make up a test circuit and try it.

Given it's a sunny day here in Cheshire, I was going to head out around my local (as in push bike home) loop and see what happens to the (new) battery. It's fully charged and showing 12.9V. AIUI, if the alternator is not keeping pace with the current draw from the ignition, then the battery will slowly discharge, and I should see a reduction in the battery voltage. I appreciate that the battery needs to have some load on it, so maybe checking it with the headlight on will provide that load, and I can check it before and after each short ride. At 1500 rpm the battery is showing 14.5V, so presumably the alternator is doing something.

If, after a ride or 2, the battery is showing signs of not being recharged, I'll have a look at the current flow between battery and the loom.

I'm keen to get to the bottom of this - I understand how the rest of the bike works, so getting to grips with the charging system is the final part of the jigsaw. I'm just a bit wary of blowing up the black box electronics (Boyer box or reg/rec) so taking it carefully. Given that a new rotor and stator is getting on for £180, it would be nice to find out what's not right first. And the new rotors seem to be a bit hit and miss in the crankshaft fit department. Given that the bike ran fine last year, the only thing that changed really was the battery and my lack of attention to keeping it charged over the 5 months or so of our record-breaking wet winter this year.
 

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I have just re-commissioned the 1972 T100R I restored last year. At that time it had a new loom, a Boyer Mk 4 system, one new coil, a 'Lucas' reg/rec (single phase) and a new Yuasa 9.5Ah lead acid battery. It also has LED headlight, pilot light and tail light (and 2 new Premier carbs). I did nearly 600 miles on it last summer with no issues at all.

Gave it new oils and a thorough check over at the weekend. Started easily on its new carbs. 14.5V when running at the battery, so presumably the alternator is working. No obvious issues, everything working.

Did a 3 mile loop near home, all well. Came home, looked for leaks etc, none. Lights good. Went out again.

3 miles down the road and a sudden loss of engine. No coughing, no warnings, nothing. I was running with the LED pilot light only. Just coasted to the side of the road. Petrol OK in the filter to the carbs. Lights work, electrics all OK it seems. Just no ignition. Recovered to home.

On checking, battery seemed a bit lower than I'd expect, around 12V, but lights all worked.

Thoroughly charged the battery (and I've now bought a new one anyway) and I had a spark at the plug. Could not find any wiring fault, coils seem to have the resistances they should have (or thereabouts). No fuses blown. Everything all clean and tidy. Nothing obviously loose.

I'm suspecting a poor battery - I will admit to not having charged it over the winter until just before I wanted to use it (so it was unused for about 4-5 months), and having now recovered the sparks at the plugs, it does seem to lose voltage quickly when the headlight is on. After charging the battery to 12.6V, it dies to about 12.2V with the LED headlight on after only a minute or 2, but recovers to about 12.5V when the light is switched off.

My question is though, given that the alternator is producing 14.5V at the battery, how can a poor battery cause an ignition problem given that it was good enough to start in the first place? If the alternator is producing even 50% of its 120W, that would be say 5A, which should be enough to run the ignition system.

I'm also looking suspiciously at the alternator - even though it's producing electrons at 14.5V, maybe it's not producing enough of them to maintain the battery charge? Any suggestions anyone?
 

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I had just the same problem with my 1969 model Saint. After many hours, testing everything on the charging side that I could think of, it turned out to be an intermittent fault with the ignition switch. You might like to look at that before spending too much time and money on testing equipment.
Good luck and good riding.
 

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If you do end up buying a new rotor & stator Andy TMS no longer sell the UK made rotor (54202299/UK). On the plus side they say they've never had a problem with the fitting of the fake Lucas unit which is contrary to my experience and that of the vendor who sold it to me, his comment was that he "wasn't surprised" that it didn't fit. Seems to be a lottery.
 

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Discussion Starter #11
I had just the same problem with my 1969 model Saint. After many hours, testing everything on the charging side that I could think of, it turned out to be an intermittent fault with the ignition switch. You might like to look at that before spending too much time and money on testing equipment.
Good luck and good riding.
Hi Peter, welcome to the forum.

The problem's not in the switch as a) it's new (but that's no guarantee) but b) all the other electrics worked. Since lights etc are all wired on the switched side of the switch, if that was duff I'd not have had lights etc.
I'm about to go out for a few short rides to see if I can deduce anything further. (or get some exercise pushing it home!)

The bike sat for 37 years in bits and I don't know how the rotor was stored, so it could be weak, although it had a habit of attracting spanners etc to it during the re-built last year so it's not all bad. Given that it all worked just fine when I put it to bed in October, I'm strongly suspecting the battery but keeping an open mind until I've tested everything I can.

It's all part ad parcel of running an old Brit bike. You just have to know how it all works and what condition all the various bits are in.
 

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Discussion Starter #12
If you do end up buying a new rotor & stator Andy TMS no longer sell the UK made rotor (54202299/UK). On the plus side they say they've never had a problem with the fitting of the fake Lucas unit which is contrary to my experience and that of the vendor who sold it to me, his comment was that he "wasn't surprised" that it didn't fit. Seems to be a lottery.
Hi Chris,
I'm keeping the parts cannon unloaded until I find out (if I can) what's actually wrong - if anything now I've fitted a new battery. I could do without buying a new rotor and then having to either find someone to ream it out to fit, or have it bored out and a sleeve fitted. It's all do-able, but I just don't want to have to. FWIW, I've just fired it up and it was giving 15V on a fast tick-over at the battery. That doesn't look like a duff alternator to me. We will see.
 

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Discussion Starter #13
Checked battery voltage before I went out, 12.6V with ignition and pilot light on. Ran around the local lanes for 30 miles and at the end the battery voltage with ignition and pilot light on, half an hour after I got back, was 12.75V, so no worse.

Stopped a couple of times during the ride and the battery voltage, with engine running was around 14.8-15V, so presumably the alternator is charging, in some fashion.

I was riding for about an hour, and if the ignition system draws 4 amps, say, that would be 4Ah used. Given that it's a 9.5Ah battery, if the 120W alternator was significantly below par, I'd have thought that the battery voltage under light load would be significantly less than 12.75V. Which gives me some confidence that it's not going to let me down again anytime soon. Famous last words.....

It'll be interesting to test the alternator to find out what t's really doing. For now, I'm too cold to go anywhere near it. It was nice in the sun, until it clouded over.
 

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I was riding for about an hour, and if the ignition system draws 4 amps, say, that would be 4Ah used. Given that it's a 9.5Ah battery, if the 120W alternator was significantly below par, I'd have thought that the battery voltage under light load would be significantly less than 12.75V. Which gives me some confidence that it's not going to let me down again anytime soon. Famous last words.....
Well done for getting out Andy, still far too cold for me. My very unscientific benchmark is that if I get back with more volts than I started with then all is well.
 

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Hi Andy,

keen to get to the bottom of this
(y)

I appreciated that that link applies to the conventional Triumph installation, and I have EI and an electronic reg/rec, so it's not directly comparable.
They are directly comparable electrically. Not much different physically.

EI vs. points is neither here nor there. The ignition circuit still has the coils that are the resistance in the circuit, the EI simply does exactly the same as the points 'n' aau, no difference to the electrical functioning. Plus EI doesn't have anything to do with charging.

Reg./rec. does the same as rectifier and Zener; if you want to measure AC Amps, it's just a matter of thinking about where to connect the Ammeter.

not sure how to connect the 1 ohm load to the alternator to check the voltage output
1. Connect each stator wire to a different end of the resistor.

2. Set a multi-meter to AC Volts (or use an AC Voltmeter), connect each meter lead to a different end of the resistor.

3. Although you're using an AC Voltmeter, you are measuring Amps, not Volts.

The relationship is Ohm's Law - E=IR (aka Volts = Amps x Ohms (Resistance)). That's the reason you use a 1 Ohm resistor, the Voltmeter connected in parallel with the resistor is also indicating Amps, (y) Reason Lucas advised testing in this way is 'back in the day', an AC Voltmeter was cheaper and easier to obtain than a specifically-automotive AC Ammeter.

appreciate that the battery needs to have some load on it, so maybe checking it with the headlight on will provide that load,
The ignition coils are a "load".

new rotors seem to be a bit hit and miss in the crankshaft fit department.
TMS no longer sell the UK made rotor (54202299/UK). On the plus side they say they've never had a problem with the fitting of the fake Lucas unit which is contrary to my experience and that of the vendor who sold it to me, his comment was that he "wasn't surprised" that it didn't fit. Seems to be a lottery.
It is. A few years ago, I recall a BritBike forum poster (without the knowledge not to) admitting to fitting his bike's rotor with a hammer ... :eek: Mind, Wassell might've finally figured out that 19 mm. isn't 3/4" (dunno if it's still on the "Lucas 🤣" website but there certainly used to be an image of the rotor showing both measurements for the centre of the rotor ...).

Bear in mind TMS aren't the only dealer selling the "Made In England" electrical bits and, even the rotor's out-of-stock everywhere, someone'll be able to tell you when they'll be back in?

Mind, this assumes your bike needs a new alternator rotor?

given that the alternator is producing 14.5V at the battery, how can a poor battery cause an ignition problem given that it was good enough to start in the first place?
You're forgetting Amps - low Amps is just as bad as low Volts.

As a battery discharges, its internal resistance falls. Again, the link between EMF (Volts), current (Amps) and resistance (Ohms) is the aforementioned Ohm's Law.

If your bike's old battery has an internal fault that causes low resistance, Ohm's Law says it'll absorb a lot of the Amps generated by the alternator, possibly not leaving enough to charge the ignition coils, meaning they don't work properly?

If the alternator is producing even 50% of its 120W, that would be say 5A, which should be enough to run the ignition system.
... if the battery doesn't have an internal fault that's absorbing a lot of the generated Amps?

Checked battery voltage before I went out, 12.6V with ignition and pilot light on.
As the pilot lamp's on, so is the tail-lamp?

Ran around the local lanes for 30 miles and at the end the battery voltage with ignition and pilot light on, half an hour after I got back, was 12.75V, so no worse.

riding for about an hour, and if the ignition system draws 4 amps, say, that would be 4Ah used. Given that it's a 9.5Ah battery, if the 120W alternator was significantly below par, I'd have thought that the battery voltage under light load would be significantly less than 12.75V.

Stopped a couple of times during the ride and the battery voltage, with engine running was around 14.8-15V, so presumably the alternator is charging, in some fashion.
Why "some fashion"? Looks pretty good from here ...

Hth.

Regards,
 

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Discussion Starter #16
Doh! Idiot. Dr Shipstone (my A level Physics master) would be horrified. I could not understand why the WM says that the AC voltage at C when measuring the alternator output across the ends of the 1 ohm load would be 8.5V. It has to be way more than that.

It's not, it's 8.5A, (from V=IR)................ 8.5V drop over a 1 ohm resistor........

Thx Stuart. As I get older I get (even) more stupid.

But not so stupid as to forget Dr Shipstone's mantra: "Its Volts what jolts, but it's mills what kills" (as in milliamps.) So watch what bits you touch with your fingers.


And, is that serendipity? Dr Shipstone taught me physics for a year in 1971/2. The T100R was first registered in April 72. If I'd known then...... He was one of those very, very few teachers who made a real difference.
 

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Well done for getting out Andy, still far too cold for me. My very unscientific benchmark is that if I get back with more volts than I started with then all is well.
😊 😊 😊

I've never really thought about it - I've never had a charging issue. I tend to listen for mechanical noises, pinking etc, but the electrics, well, just work, for me. In fact, as I said to the recovery van driver on Sunday, in nearly 50 years of driving and motorcycling, I've never had to call for a recovery truck. Except maybe for the time when the crank broke in my old student days Moggy Minor, letting me down in Gargrave on the way back from a geology field trip on Skye. He came up from Boston with a trailer and took it home. We put a new crank in it and I then took it to Northern Spain on another field trip.

I'm thinking of temporarily fitting one of these:


just to give me some real-time data as I ride it.


In other news, can't get the newly-rebuilt Tiger 750 to run. It coughs and spits, and kicks a bit, but it won't run. I'll have to check the timing again, and I did see that the air screw is way too far in (so too rich) but at least it's trying.
 

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Hi Andy,
I think the voltmeter is a great idea until your confidence returns in the bikes ability to get back home.

One thing I found strange with this thread is no one has mentioned checking the ignition it’s all been about batteries and charging and low voltage on the Boyer, however it is my impression the the mk4 was built to resolve voltage sensitivity problems.

I am not convinced that the ignition or the torturous route devised by Triumph/Lucas has been investigated closely enough to renew your confidence.

If it was my bike; I would fit a fused wire directly from the battery to the coil/ignition feed, and keep the fuse in the pocket of my riding jacket. If I was stranded again, there is a chance that the problem will be in the power feed to the ignition. You might get out of trouble by just by passing the standard wiring and popping the fuse in.
Of course, if there is a problem with the E.I there is nothing you can do.
If it is a charging fault you can preempt a problem by monitoring the voltmeter.
I would check the Boyer and all connections including return path carefully, especially the pickup wiring and backplate for cracks, loose coils and dry solder joints.
I do hope everything works fine from now on, I am just fearful that the charging issue is just a sideshow impeding investigation of problem waiting to leave you abandoned at the side of the road again.

When you said everything just cut out, no warning, no misfire beforehand it felt to me that it was less likely to be a symptom of a battery running low on volts. In the case of the battery the cut out is more when you brake or indicate and the bulbs drop the last bit of voltage away, cutting the ignition.

With the 750 you don’t say how much of a rebuild it has had.
If the cam timing wheels have been removed/disturbed, the coughing and spitting might be a sign of bad cam timing. I have seen at least one manual that shows the 650cc cam timing labeled as 750cc cam timing.
With the ignition timing check that the 38 degs beforeTDC timing mark on the alternator has been used to set up, not the 38 degs before BDC mark, they both look exactly the same.

good luck
Regards
Peg.
 

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Discussion Starter #19
Hi Peg, thx for that.

It was at the back of my mind that if it was the battery then I'd have expected a warning of some sort. So that's still a nagging doubt. Given the instantaneous nature of the fault, I suspected a duff Boyer unit, or a poor connection in the power to the Boyer box, or maybe its earth, but I couldn't find anything, and waggling the leads since then have not reproduced the fault. I have nipped up a few crimps though and replaced the G/W and G/Y lead to the pickup - it looked OK, but I had some spare coloured wire so changed it. An intermittent fault there would have caused an instant stop.

I like the idea of a separate fused feed to the Boyer - I'll do that until my confidence has returned.



I rebuilt the 750, and I was careful to mark the cam pinions when I took it apart and equally careful that they went back the same way, so I'm 99% sure it's not the cam timing. Furthermore, the valves seem to open and close when you'd expect them to, but clearly I could be a tooth out - but atm I doubt it. The whole engine's been gone through over the winter, bushes, bearings, rebore, valves and guides, big ends - the lot.

I bought the 750 as a non-runner last spring and in getting it going I marked the relevant timing mark on the rotor - seeing that there are 2 marked on it. It has a Boyer Mk3 unit. That mark is where it lines up to now, so that seems to be OK. The magnets are under the pickup coils when the rotor mark is where it should be. However, I'l have another look shortly. That it's trying tells me it's a timing issue, somewhere. But, I got this going last year and had to re-time it then, and I later rebuilt my T100R with a Boyer unit, so I must be able to get it right some of the time.

I did notice this am that the air screw was only half a turn out - I stripped and cleaned the carb over the winter - so it would be trying to run rich, I've moved it out to 2 turns so we'll see if that does it. It's a dead easy bike to start normally, so I can't be far off it. Timing and carb - if its got a spark and petrol at the right time, it should run.
 

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In other news, can't get the newly-rebuilt Tiger 750 to run. It coughs and spits, and kicks a bit, but it won't run.
If EI (I can't keep track of all the bikes on all the forums), try swapping the 2 wires to the ignition stator. That has "fixed" the issue you mention several times for me, on BRAND NEW, PERFECTLY WIRED units (Sparx, Pazon and Boyer).

The EI "brain" is calculating the rotor position relative to CW or CCW rotation depending on whether Triumph or Norton/BSA. If it's backwards, it's not going to work.
 
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