Britbike forum

Lucas Rita ignition no sparky

Posted By: Hillbilly bike

Lucas Rita ignition no sparky - 06/24/18 8:18 pm

I I just bought what appears to be an unmolested 79 T140 Special.Lucas Rita original ignition system... It was a daily rider in New York city so its a bit weathered but looks like it was mechanically cared for.. The seller was riding the bike...The engine was cold and it took three good kicks to fire it up, the bike ran fine.. Once I got the bike home it again took three kicks and then ran ok for a short ride...That was it, wouldn't start after that, dead...No spark...The battery is fully charged and the headlight is bright...I checked all the grounds, this is a negative ground machine..I added a temporary ground wire from the battery negative to the head and spark plug for testing... The two wires from the pick up read 650 ohms between them. I wiggled the wires right on the pick up, no change...The greasy control box on the right side cover looks original.There a ground wire running to the battery box securing bolt that's good..With the ignition on, there's battery voltage on the white wire..the other two wires, white with black and black show continuity to ground..Both coils measure 1.8 ohms on the primary terminals.The wiring is good, substituted spark plugs...Still nothing
Are there any other home type tests than can be done with a multi meter ? I'm suspecting the control box is faulty and if so may be better to just buy an aftermarket ignition....Thanks
Posted By: HawaiianTiger

Re: Lucas Rita ignition no sparky - 06/24/18 9:21 pm

I'll bet John has some diagnostic info on the Rita. Who else would?
There are stories of guys un-potting the Rita box and replacing transistors, etc. Sounds like too much work to me.
Cheers,
Bill
Posted By: koan58

Re: Lucas Rita ignition no sparky - 06/24/18 9:26 pm

It would appear you are damned if the Rita failed just after purchase! I don't believe it, it is probably the sturdiest EI ever made.
Double check polarities cos they're a bit mixed at this period. Dunno whether the box (AB11) would still need a ground for the case? Stuart has followed these more closely, wait expectantly?
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/24/18 9:33 pm

Bill...Yes, too much trouble..... I bench tested both coils...Using a 12 volt battery they throw a blue spark across a near 1/4 inch gap.. It would be my luck it crapped out right after I bought it...
Posted By: koan58

Re: Lucas Rita ignition no sparky - 06/24/18 9:42 pm

6v coils in series?
Posted By: Stein Roger

Re: Lucas Rita ignition no sparky - 06/24/18 9:44 pm

Congrats with the new bike Tony! Sucks acid it stopped on you...

The RITAs rarely fail they say, but it happens. If Tony couldn't fix it, it's probably dead. I killed an AB5 once, a "polarity issue" you can say...

Help is to be found, but I haven't heard or read anything about these units yet:
http://www.rexs-speedshop.com/epages/es143131.sf/en_GB/?ObjectPath=/Shops/es143131/Products/LRR-V1
Posted By: gavin eisler

Re: Lucas Rita ignition no sparky - 06/24/18 9:52 pm

I have a couple of Rita stories, in 1982 a chap on a new Bonneville stuck at the side of the road, its was fresh from the showroom, no sparks, tried to help him but couldnt,. years later I bought a Rita new from Devimead, the A65 was supposed to run better that way, it was easier to start ( previously had fixed advance, so it could bite back at times), it always bothered me that the rotor part was called a " reluctor" in the set up literature, the setting of air gaps being quite critical, however it did run pretty well, it was still OK when I changed it for a Boyer Micro Digital, that was 20 plus years ago ( three things bothered me about it, the word Lucas, the broke down bonnie, and the word reluctor). Got it in a box somewhere, took it to an auto jumble , no one wanted it, still have it somewhere, you are welcome to it , if you want it.

Before you do that , try drying the box out in a warm cupboard/ airing cupboard, boiler room or such.
Give it a few days, maybe run the box ground straight to the battery pole to cut out any nonsense. might just be damp.
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/24/18 9:54 pm

More tests... I touched one of the two wires on the pick up to earth...Each time I earth it, a sizzling blue spark from both plugs
Posted By: koan58

Re: Lucas Rita ignition no sparky - 06/24/18 10:03 pm

Rita is one of the ordinary old EI's that will spark when you turn the ignition off. If you can't get that, don't kill yerself kicking it. Re-sort the wires until that happens, then kick it. I don't believe the Rita has died on you!
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/24/18 10:29 pm

Originally Posted by koan58
Rita is one of the ordinary old EI's that will spark when you turn the ignition off. If you can't get that, don't kill yerself kicking it. Re-sort the wires until that happens, then kick it. I don't believe the Rita has died on you!

Yes, it throws a spark if when the ignition is turned off...When the ignition is switched on it usually throws a weak spark, sometimes immediately and sometimes after a second or two...sometimes not at all..
Posted By: koan58

Re: Lucas Rita ignition no sparky - 06/24/18 11:53 pm

Not sure that added anything to it, it is when you turn ignition off that you should get a spark. Depending how many things need power, the switch on voltage always rises more slowly than it vanishes after turning off. The important thing is that you get a spark when turning power off.
This confirms, or otherwise, that the basic box is connected and working. It doesn't need the 2 wires from the pickup to even be connected. So you can even put the box on the bench, with coils and plugs and test it from a battery, just by flashing one of the leads to the coils. Spark or no spark.
Posted By: koan58

Re: Lucas Rita ignition no sparky - 06/25/18 12:02 am

Not sure that added anything to it, it is when you turn ignition off that you should get a spark. Depending how many things need power, the switch on voltage always rises more slowly than it vanishes after turning off. The important thing is that you get a spark when turning power off.
This confirms, or otherwise, that the basic box is connected and working. It doesn't need the 2 wires from the pickup to even be connected. So you can even put the box on the bench, with coils and plugs and test it from a battery, just by flashing one of the leads to the coils. Spark or no spark.
No spark - box seems U/S
Spark - try flashing the trigger wires together to get a spark, if it does the only thing left is the trigger unit, which you've already measured as having reasonable ohms.
I so doubt that the Rita has given up on you.
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/25/18 10:57 am

Originally Posted by NickL
If you're not in a panic for it Tony, i can test/repair it for you, they are very simple units and are normally very reliable.
They are easy to repair/fault find any reasonable radio/tv guy should have no problem with it.

Nick

Make sure the box is well earthed, it relies on the case earth for it's internal overvoltage protection.

Nick, thanks for your offer....I would really like to ride the bike now because the longer it sits on the work table, the more likely I'll start fixing stuff that doesn't really need to be fixed,.. grin....
The box is well earthed...All wiring as it should be and tested good......The control unit produces a snappy blue spark when bench tested as mentioned above but nothing when the engine is kicked over with a good battery..Although the pick magnet seems ok and has the 650 ohms....I don't kick over the engine and check the pick up for a voltage signal.. I'll do that today and let you know...
I just ride my Ducati 900 Monster and pretend it's a Triumph................................
Posted By: dave jones

Re: Lucas Rita ignition no sparky - 06/25/18 1:04 pm

My 3TA with Rita would suddenly stop running. It would start if I took the main fuse out but run roughly. If I replaced the fuse once started it would sometimes stop again but other times run properly. I didn't really understand about it then but it could just have been a battery issue. It was usually ok and would run really well at night with the lights on even if the battery was flat. The lights at a junction would be very dim but it would run fine.

Dave
Posted By: Stuart

Re: Lucas Rita ignition no sparky - 06/25/18 2:46 pm

Hi,

Originally Posted by Hillbilly bike
control box
ground wire running to the battery box securing bolt that's good.

'Fraid not, as much use as a chocolate teapot ...

Supply is the Black wire from battery -ve. Btw, have you had a look inside the 3-pin plug that connects the Rita to the main harness?

Switch supply from the amp. to the coils is the White/Black wire to (as standard) the timing-side coil -ve terminal.

Return for the amp. electronics themselves is the White/Yellow to (as standard) the drive-side coil +ve terminal. The other White/Yellow on the drive-side coil +ve is the return from the coils series and continues the electronics return to the kill switch, kill switch connects to a White wire to ignition switch terminal #2, Brown/Blue from ignition switch terminal #1 through the fuse to battery +ve completes the 'normal' ignition circuit.

The only connection to 'ground' through the amp. casing is from the internal Zener for spike protection. Only if the amp. is rubber-mounted does the case need a 'ground wire', which should be to the battery terminal itself. If the amp. is rubber-mounted, ever needs spike protection and there isn't a good electrical connection from the "battery box securing bolt" to battery -ve itself, the amp. doesn't have any spike protection.

Originally Posted by Hillbilly bike
I'm suspecting the control box is faulty

Seems amazing that the guy was using it as a daily rider, you bought the bike and the amp. stopped working?

Originally Posted by koan58
Rita is one of the ordinary old EI's that will spark when you turn the ignition off.

+1. Ime, the plugs usually spark when the ignition circuit is broken (e.g. turn off the ignition switch). Might not happen every time but only if it doesn't happen at all despite making and breaking the ignition circuit several times do you worry about the amp.

Originally Posted by Hillbilly bike
When the ignition is switched on it usually throws a weak spark, sometimes immediately and sometimes after a second or two...sometimes not at all..

Ime, the plugs never spark when the ignition circuit is 'made' (e.g. ignition switch turned on); if the plugs do seem to spark when the ignition circuit is 'made' , that's something like a faulty switch - corrosion, worn contacts, dodgy connection or wire, etc. causing intermittent breaks as the switch is operated.

What's the rubber cover over the ignition switch like? '79 originally had the same cover as the T160, with a 'slot' in the cover for the ignition key. Even if this hasn't been worn into a hole, rain-water, condensation, washing water, etc. is going to get into the switch especially on a daily rider in NY. frown Rebuild the ignition switch to better than new; even before Wassell was allowed to brand its rubbish "Genuine Lucas", I found 'original Lucas' ignition switches better than pattern - the one on my first T160 is the original, the one on my second T160 is the one I replaced a pattern one with in 1982.

Whether you rebuild or replace, before refitting on the bike, drill a small hole in the terminals backing at what'll be the lowest point when it's refitted - lets any water that does get in drain straight out. thumbsup Also replace the '79 switch nut and cover with the '82 97-7120 Nut, 97-7123 Ignition key cap and 60-7335 Ignition switch cover.

Originally Posted by Hillbilly bike
I touched one of the two wires on the pick up to earth...Each time I earth it, a sizzling blue spark from both plugs

The recognised test is touching amp. White/Purple to (-ve) earth should generate a spark at the plugs, as does passing a screwdriver across certainly the common aftermarket-Rita pick-up; haven't tried the latter on a '79-on standard 5PU?

Originally Posted by gavin eisler
try drying the box out in a warm cupboard/ airing cupboard, boiler room or such.
might just be damp.

If it starts working again after that, remove the side of the amp. held with four small hex, screws, clean off the sealant, check the wires seal, reseal the side - Rita internals should never be affected by damp.

Otoh, John's reported in the past that the original position of the 3-pin plug means it catches crap off the back wheel. He said there was a modified one, so you might to check what the modified one looks like? Like plug connectors on Japanese bikes, I exclude moisture from my T160's Rita plugs by filling 'em with Vaseline (petroleum jelly) when assembling;

Originally Posted by gavin eisler
maybe run the box ground straight to the battery pole to cut out any nonsense.

As with any e.i., you can bypass the switches, fuse and wiring in the ignition circuit return by - in this case - a wire from (as standard) drive-side coil +ve direct to battery +ve. You might also want to try a wire from battery -ve to the amp. Black wire, to bypass the standard negative feed wiring.

Originally Posted by Hillbilly bike
the pick magnet seems ok

If it turns out not to be ok, a replacement - based on the earlier and more-reliable 'aftermarket Rita' pick-up - is available from a British seller.

Hth.

Regards,
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/25/18 3:55 pm

Originally Posted by Stuart
Hi,

Originally Posted by Hillbilly bike
control box
ground wire running to the battery box securing bolt that's good.

'Fraid not, as much use as a chocolate teapot ...

Supply is the Black wire from battery -ve. Btw, have you had a look inside the 3-pin plug that connects the Rita to the main harness?

Switch supply from the amp. to the coils is the White/Black wire to (as standard) the timing-side coil -ve terminal.

Return for the amp. electronics themselves is the White/Yellow to (as standard) the drive-side coil +ve terminal. The other White/Yellow on the drive-side coil +ve is the return from the coils series and continues the electronics return to the kill switch, kill switch connects to a White wire to ignition switch terminal #2, Brown/Blue from ignition switch terminal #1 through the fuse to battery +ve completes the 'normal' ignition circuit.

The only connection to 'ground' through the amp. casing is from the internal Zener for spike protection. Only if the amp. is rubber-mounted does the case need a 'ground wire', which should be to the battery terminal itself. If the amp. is rubber-mounted, ever needs spike protection and there isn't a good electrical connection from the "battery box securing bolt" to battery -ve itself, the amp. doesn't have any spike protection.

Originally Posted by Hillbilly bike
I'm suspecting the control box is faulty

Seems amazing that the guy was using it as a daily rider, you bought the bike and the amp. stopped working?

Originally Posted by koan58
Rita is one of the ordinary old EI's that will spark when you turn the ignition off.

+1. Ime, the plugs usually spark when the ignition circuit is broken (e.g. turn off the ignition switch). Might not happen every time but only if it doesn't happen at all despite making and breaking the ignition circuit several times do you worry about the amp.

Originally Posted by Hillbilly bike
When the ignition is switched on it usually throws a weak spark, sometimes immediately and sometimes after a second or two...sometimes not at all..

Ime, the plugs never spark when the ignition circuit is 'made' (e.g. ignition switch turned on); if the plugs do seem to spark when the ignition circuit is 'made' , that's something like a faulty switch - corrosion, worn contacts, dodgy connection or wire, etc. causing intermittent breaks as the switch is operated.

What's the rubber cover over the ignition switch like? '79 originally had the same cover as the T160, with a 'slot' in the cover for the ignition key. Even if this hasn't been worn into a hole, rain-water, condensation, washing water, etc. is going to get into the switch especially on a daily rider in NY. frown Rebuild the ignition switch to better than new; even before Wassell was allowed to brand its rubbish "Genuine Lucas", I found 'original Lucas' ignition switches better than pattern - the one on my first T160 is the original, the one on my second T160 is the one I replaced a pattern one with in 1982.

Whether you rebuild or replace, before refitting on the bike, drill a small hole in the terminals backing at what'll be the lowest point when it's refitted - lets any water that does get in drain straight out. thumbsup Also replace the '79 switch nut and cover with the '82 97-7120 Nut, 97-7123 Ignition key cap and 60-7335 Ignition switch cover.

Originally Posted by Hillbilly bike
I touched one of the two wires on the pick up to earth...Each time I earth it, a sizzling blue spark from both plugs

The recognised test is touching amp. White/Purple to (-ve) earth should generate a spark at the plugs, as does passing a screwdriver across certainly the common aftermarket-Rita pick-up; haven't tried the latter on a '79-on standard 5PU?

Originally Posted by gavin eisler
try drying the box out in a warm cupboard/ airing cupboard, boiler room or such.
might just be damp.

If it starts working again after that, remove the side of the amp. held with four small hex, screws, clean off the sealant, check the wires seal, reseal the side - Rita internals should never be affected by damp.

Otoh, John's reported in the past that the original position of the 3-pin plug means it catches crap off the back wheel. He said there was a modified one, so you might to check what the modified one looks like? Like plug connectors on Japanese bikes, I exclude moisture from my T160's Rita plugs by filling 'em with Vaseline (petroleum jelly) when assembling;

Originally Posted by gavin eisler
maybe run the box ground straight to the battery pole to cut out any nonsense.

As with any e.i., you can bypass the switches, fuse and wiring in the ignition circuit return by - in this case - a wire from (as standard) drive-side coil +ve direct to battery +ve. You might also want to try a wire from battery -ve to the amp. Black wire, to bypass the standard negative feed wiring.

Originally Posted by Hillbilly bike
the pick magnet seems ok

If it turns out not to be ok, a replacement - based on the earlier and more-reliable 'aftermarket Rita' pick-up - is available from a British seller.

Hth.

Regards,


Let me clarify my statements....I mentioned the ground wire from the case to the frame because the case has a sticker "case must be earthed" I did mention the three circuit plastic connector has a black ground wire .. Both the black wire and white wire on the connector will light a test lamp connected accordingly on the module side of the connector ...
I have tested it directly off the battery .. I have tested the bike wiring several times and it's good.The various connections are not corroded and I did clean them just to be sure.. The wiring is all original... I just hooked up a digital VOM to the two pick coil wires at the control box..Working the kick starter by hand with spark plugs removed shows .024 volts on DC and about .100 volt on AC scale...
And I have shut off perfectly good running autos ,and an hour later wouldn't restart because an ignition module failed...

I pulled the back cover off the control box ...Nothing loose, the wires feeding in all have continuity...I'm a retired construction electrician not an electronics technician but my nose says it smells a bit toasty inside...Maybe I'll send it off to Nick L...

[Linked Image]


Posted By: AngloBike

Re: Lucas Rita ignition no sparky - 06/25/18 7:43 pm

I always thought that the units were potted?
I.e. Sealed with epoxy?
Maybe someone's been in there before
Posted By: BikeVice

Re: Lucas Rita ignition no sparky - 06/25/18 9:50 pm

I have 2 working amps, a working pickup/reluctor and a bench top test harness made from a melted T140E wiring harness you can borrow if you like. PM me if interested and I'll drop it all in the mail.


Eric
Posted By: John Healy

Re: Lucas Rita ignition no sparky - 06/25/18 10:54 pm

If this has already been mentioned please ignore.
Just for giggles look inside the headlamp. What you want to look for is a white plastic connector with two wires in and out of it. The colors will be white/yellow and white. It is the connector to the kill button. Check the color of the white plastic. If it is discolored the connection has gone high resistance and burnt the connections. Very common problem.

Modern replacement harnesses have gone back to bullet connectors as we did in the day.
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/26/18 12:43 am

John, The kill switch wasn't hooked up when I got the bike and the seller said it was that way he he bought it. .....Despite the bike's weathered finish, all the wiring connections were clean and sound including the grounding wire for the ignition control box case..
For me, messing with 39 year old electronic components just has become not worth the aggravation considering for $120 a new Pazon or Boyer can be at my door in a few days.and no need to butcher the original wiring to install it...
Other than replacing the front wheel bearings this heap is fit for the highway...if it had a working ignition grin
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/26/18 11:10 am

Ok, new plan, the Lucas Rita ignition is going to be repaired by a member here, and another member is loaning me a working system to use temporarily...Nice!
Posted By: Stuart

Re: Lucas Rita ignition no sparky - 06/27/18 6:29 pm

Hi,

Originally Posted by Hillbilly bike
Let me clarify my statements....I mentioned the ground wire from the case to the frame because the case has a sticker "case must be earthed"

Lucas considered just mounting the Rita amp. on a metal part of '79-on twins to be sufficient "earth" for the spike protection; a wire from the case is only required if the amp. is rubber-mounted; then Lucas advised the wire should be connected to the 'earth' battery terminal; because, if it was connected to some other part of the bike, and the connection between that part of the bike and the 'earth' battery terminal wasn't working, the case would not be "earthed".

So, if the amp. on your bike is mounted to another metal part of the bike, but the p.o. didn't consider just the mounting to be a sufficiently-good "earth", a wire from the case just to some other part of the bike isn't any improvement on standard; if a wire's been added, the "improvement" is to connect the other end to the battery terminal itself.

Originally Posted by Hillbilly bike
I have shut off perfectly good running autos ,and an hour later wouldn't restart because an ignition module failed.

I didn't say it was impossible, I was just agreeing with Dave's observation, based on long-time first-hand experience of Ritas, mine and others.

Originally Posted by Hillbilly bike
I just hooked up a digital VOM to the two pick coil wires at the control box..Working the kick starter by hand with spark plugs removed shows .024 volts on DC and about .100 volt on AC scale.

Afaik, neither Lucas nor Triumph supplied comparison values? The test value they offered was the resistance of the pick-up - 650 Ohms. lso advised is to test from the ends of the White/Purple and White/Orange wires detached from the amp.; I'm guessing because the 650 Ohms was/is the resistance of the pick-up coil itself, so any higher reading would indicate a problem in the wires?

However, 650 Ohms is possibly only the 'early' pick-up coil resistance; certainly there's another at 1000-1200 Ohms. So if you see certainly the higher resistance, you still have to check the wires separately between the amp. connections and the pick-up connections, in case the pick-up coil itself is ~650 Ohms and the additional resistance is in wires and/or terminals.

Hth.

Regards,
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/27/18 7:57 pm

Originally Posted by Stuart
Hi,

Originally Posted by Hillbilly bike
Let me clarify my statements....I mentioned the ground wire from the case to the frame because the case has a sticker "case must be earthed"

Lucas considered just mounting the Rita amp. on a metal part of '79-on twins to be sufficient "earth" for the spike protection; a wire from the case is only required if the amp. is rubber-mounted; then Lucas advised the wire should be connected to the 'earth' battery terminal; because, if it was connected to some other part of the bike, and the connection between that part of the bike and the 'earth' battery terminal wasn't working, the case would not be "earthed".

,

...The control box is mounted the inside of right side triangular side cover that bolts to the cast metal airbox..The ground wire from the control box case to the upper battery box bolt have die made crimps that fit perfectly..Not something made with typical crimpers...The other earth connection is at the three terminal plastic connector and is part of the wiring harness feeding the control box...Also present is the ground on the top engine stay...All grounds were sound, clean and showed zero resistance... Many years of accumulated oil and dirt preserved the bolted connections from corrosion..
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 06/28/18 10:36 pm

A guy here, "Bike Vice", send me a loaner Lucas Rita ignition to use for a few months...I plugged it into my bike's wiring and it throws a fat blue spark...I have the carbs back together but the rubber inlet boots are crap so have to with a few days until they arrive...
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 07/13/18 3:21 pm

So the adventure continues....Bike Vice (Eric) sent me a loaner Lucas Rita Control box(AMP) and pick up...Kicked over the bike with the loaner and we have ignition...It takes many kicks to get the engine fired up...It runs poorly, very rich...I shut it down after about a minute or two..Carb investigation reveals the cold start plunger seal on one carb has disintegrated....i order a bunch of carb parts and in a week all is good ... Again,it takes many kicks to fire the engine...It starts ,no over rich issue but it's back firing out the exhaust a bit...Most likely the sparks plugs are still a bit fouled from the past rich fuel mixture...About a minute later the engine quits,,,No spark..Great! the man loans me parts and I smoke em....But....I do some checking because Eric wondered if there could be AC voltage sneaking past the rectifier that could ruin the control box...Nope, the stock three phase rectifiers tests good with a diode checker and a test light...All the wiring is without fault...It's a very simple system, not much to screw up...Also keep in mind I was a construction electrician and contractor and 15 years ago I was modifying later electronic ignitions to fit in vintage auto engines and selling them..So supposedly I know something... crazy
So I do more testing this morning...I take off the pick up ,hold it in my hand and spin the reluctor by hand....Yup the damn thing throw a spark...But it won't throw a spark when installed in the timing cover...Something is very odd here....I'm sure the loaner Lucas Rita is working ok, just not on my bike....



I'm going to send back the loaner...Nick L is going to look at and repair as needed my Lucas Rita.....Meanwhile I just bought a Pazon EI.....I should know better than to fuss around with 40 year electronic parts..

Posted By: Stuart

Re: Lucas Rita ignition no sparky - 07/13/18 11:42 pm

Hi,

Originally Posted by Hillbilly bike
I just bought a Pazon EI

If you're buying from NZ, Al Osborn in GB has replacement Rita trigger units.

Regards,
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 07/14/18 1:15 am

Originally Posted by NickL


The rotor gap is important, it should only be about 10 thou, the rotor must not contact the stator.
There should be no connection between the pickup connections and ground.
If you remove the box from the frame does it spark when the rotor is turned then?


I took off the grounding wire to the case...Holy crap it sparks when the pick is mounted and the engine kicked over........So what goes on, the case grounding is supposedly to protect the control box... Something inside has failed?

I bought the Pazon just to use and as a back up until mine retuns...
Posted By: Stuart

Re: Lucas Rita ignition no sparky - 07/14/18 8:01 am

Hi,

Originally Posted by Hillbilly bike
Originally Posted by NickL
If you remove the box from the frame does it spark when the rotor is turned then?

I took off the grounding wire to the case...Holy crap it sparks when the pick is mounted and the engine kicked over.

[whisper]... I did point out earlier that the wire wasn't standard and shouldn't be required ...[/whisper]

Nevertheless, I'm intrigued ... for my education: was the box detached from the bike, or just the "grounding wire"? Reason I ask is Lucas and Triumph worked on the basis that the box protection worked simply through the box's original mounting. If everything's working with the box still attached to the bike, just the additional wire detached, something else is going on.

Originally Posted by Hillbilly bike
bought the Pazon just to use and as a back up until mine retuns...

Advance apologies if this is obvious already, but the Pazon can be plugged into the existing supply, return, coils and trigger wiring using the Rita's 3-pin plug and two bullet terminals.

Regards,
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 07/14/18 10:29 am

Originally Posted by Stuart
Hi,

Originally Posted by Hillbilly bike
Originally Posted by NickL
If you remove the box from the frame does it spark when the rotor is turned then?

I took off the grounding wire to the case...Holy crap it sparks when the pick is mounted and the engine kicked over.

[whisper]... I did point out earlier that the wire wasn't standard and shouldn't be required ...[/whisper]

Nevertheless, I'm intrigued ... for my education: was the box detached from the bike, or just the "grounding wire"? Reason I ask is Lucas and Triumph worked on the basis that the box protection worked simply through the box's original mounting. If everything's working with the box still attached to the bike, just the additional wire detached, something else is going on.

Originally Posted by Hillbilly bike
bought the Pazon just to use and as a back up until mine retuns...

Advance apologies if this is obvious already, but the Pazon can be plugged into the existing supply, return, coils and trigger wiring using the Rita's 3-pin plug and two bullet terminals.

Regards,


Stuart, in order for the "protection circuit" to function the case must be grounded as you know...The case is bolted to the metal side cover that's bolted to the metal air box that's bolted to the frame..That was the situation when I bought the running bike that also had a the ground wire installed and it appeared to be factory made..The wire is a redundant ground for whatever reasons..It's also my opinion the control box was never removed in the past. In fact the coils, wiring harness, charging system components and most of everything on the bike all look unmolested.
Although the stock rectifier and zenor tested good, and the system voltage was withing limits with good connections on the battery and the bike was running with the head light on and never reved over 4000 rpm..There was some sort voltage spike that killed the protection circuit on the control boxes. Interesting, the seller rode this bike for 5 years and the minute I get the bike it all goes to hell...
I bought a Podtroncs to replace the recitifer and zenor...The existing electronic ignition wiring will be tucked away and not used other than the switched ignition wire.
There's a lesson here...In the past I always went through the wiring harness and replaced all the connections and much of the wiring before riding the bike...On this one it was all original and appeared in good shape....so I left it as is...A clear violation of my own code .... grin
Posted By: Stuart

Re: Lucas Rita ignition no sparky - 07/14/18 11:43 am

Hi Tony,

Originally Posted by Hillbilly bike
in order for the "protection circuit" to function the case must be grounded
The case is bolted to the metal side cover that's bolted to the metal air box that's bolted to the frame..That was the situation when I bought the running bike that also had a the ground wire installed and it appeared to be factory made..The wire is a redundant ground for whatever reasons..It's also my opinion the control box was never removed in the past.

Hmmm ... possibly the Rita's "protection device" ground path, just through bits of bike, stops working through the ageing process's accumulation of dirt and/or corrosion between the bits? The wire from the box mounting on your bike started out as good idea, but didn't work when needed because the other end was attached to a bolt in a rubber bush?

Putting bits of information together ... the original AB5 amp. on my first triple was rubber-mounted and had a wire from the case connected to the bike's Red wires; even when John (Carpenter - Mistral Engineering) upgraded that to an AB11, although it wasn't rubber-mounted, John still attached a wire from one of the mounting bolts into the bike's Red wires. So a wire from a '79-on twin's Rita box mounting is a good idea today, but the other end must be connected either to harness Black wires or battery -ve itself, not some random bit of bike?

Thanks for your help..

Regards,
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 07/14/18 1:29 pm

Stuart...You explanation makes me think the wire isn't original.. or it was just what Meriden Co op did that day?

I took the AMP box apart....The only connection to the metal case is the black wire soldered to what looks like a diode mounted on the case. Following the printed circuit path, it travels from the diode? mounted on the case to the two retaining screws on the large power transistor and then to the white wire with black stripe that travels to the coil negative terminal...The new ignition coils have 12 volts feed into + on one coil,then the negative of that coil goes to the + of the second coil and the - of that coil is the white /black wire...Pretty simple....If the device mounted on the case is a diode, my meter says it's open in both directions.....I tested the various resistors in situation and they all have some value,none are open..I didn't test the power transistor or the several capacitors....
I was a construction electician, power distribution, big wires, big conduit...My knowledge of electronics is limited.....Any know what going on here? How can the case ground have any effect on operation when the "diode" is open in both directions? Is it some sort of trick zenor? There's a slight odor of burnt electronic components and the fiber disc on the "diode" is cracked and bulged up a bit....

[Linked Image]
Posted By: bodine031

Re: Lucas Rita ignition no sparky - 07/14/18 2:41 pm

Diode is a one way road
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 07/14/18 3:18 pm

Originally Posted by bodine031
Diode is a one way road

Yes, with the case grounded as required, no spark...case not grounded, it's sparks....If the diode is open in both directions how does it have any effect on the sparking situation??? I suspect other components like the power transistor are part of this?
Posted By: L.A.B.

Re: Lucas Rita ignition no sparky - 07/14/18 5:26 pm

Originally Posted by Hillbilly bike
....Any know what going on here? How can the case ground have any effect on operation when the "diode" is open in both directions? Is it some sort of trick zenor?



Varistor?
https://en.wikipedia.org/wiki/Varistor

https://www.accessnorton.com/NortonCommando/lucas-rita-ignition.11527/#post-159578
Originally Posted by dynodave

A genuine "A" version used a varistor for protection in either + or - ground.
A genuine "B" had deleted that build design though the instructions were never updated by Mistral. It used a specific new type transistor (boyer used same)....when that transistor production was terminated the Rita stopped production. Boyer had already moved to a different transistor and therefore did not affect them. Though I am still way too busy to solicit much work, both the "A" and "B" RITA that I repair are done as the "B" version without varistor and grounding the case does nothing.

Posted By: bodine031

Re: Lucas Rita ignition no sparky - 07/14/18 7:06 pm

So is the signal going to ground??
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 07/14/18 8:04 pm

Originally Posted by bodine031
So is the signal going to ground??

The transistor base is grounded as well as the diode thing...This circuit seems to be the trigger to fire the coils,,,The coil feed is always hot when the ignition is on..
Here's a circuit scematic from the internet...I don't know if it's dead accurate

[Linked Image]
Posted By: Hillbilly bike

Re: Lucas Rita ignition no sparky - 07/15/18 10:52 am

Nick, thanks for the explanations, there's a lot of crap on the internet.......
Posted By: Lorenzo

Re: Lucas Rita ignition no sparky - 07/16/18 4:06 pm

Re : Earthing the amplifier box -

"[whisper]... I did point out earlier that the wire wasn't standard and shouldn't be required ...[/whisper]"

Both my Rita-equipped Tiumphs came to me with the earthing wire fitted, similar to Hilbilly's. (I have no way of telling if it was OE fitting in either case, of course)

Owner's handbook (60-7091) for the Bonneville states under 'Electrical Equipment' :-
"IMPORTANT NOTE - The ignition system must only be operated with the amplifier case earthed"

Triumph's own wiring diagram in both this handbook and the workshop manual show the AB11 amplifier case earthed by what I interpret as a discrete (i.e. wired)
connection.

Triumph go further by listing this earth connection in '79 parts list 99-7102 and giving it part no. 60-7199 "Earth lead for amplifier box".

Makes it pretty standard for me...........I leave it for the experts out there to decide if it is/is not now redundant.
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