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Diagnosis please #745460
08/14/18 10:34 am
08/14/18 10:34 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Uncle D  Offline OP
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Northern Territory, Australia
A65T with new AMAL Premier, Sparx EI & regulator, copper wire HT leads, no resistor caps, B8ES plugs, Lucas coils (2x12v in series). Bike had fried a Sparx EI module apparently due to a faulty rotor (but in hindsight perhaps a lack of resistor plugs or caps)...it was replaced approx 12 months ago & was starting and runnng very well (too bloody well obviously).

I had done about 50km at 65mph when suddenly lost power with backfire and flame out exhaust (a colleague said flame from left pipe). The bike then began to run rough / missing and I reached down and felt the plug caps, getting a shock from the left cap only). Plug inspection revealed soot / dry left plug and normal right plug. One of the alternator plugs was disconnected but not sure if the was caused during my fiddling on the side of the road. Kickback while attempting to start. If it starts, backfires and runs rough, then stalls.


Back home and can report the following.
Battery holds 12.4 volts. Alternator provides 13.5v to battery so it and regulator OK.
Switched out the Sparx module for a Boyer MkIII with immediate improvement but still runnng rough (not firing on right cylinder).
Brand new battery, new resistor plugs (BR8ES), new 12v coils, new Lucas ignition switch. Cleaned all earths /replaced some earth connectors.
Fixed a wire that had come off of the oil indicator lamp in headlight.
Continuity throughout the system with no voltage lost in ignition switch circuit.
Power reaching EI module.
Both old and new coils show same resistance (around 4ohms I think).
Trigger connections at stator are sound with continuity through to EI module.

This is one of those cases where something simple may have been complicated by much fiddling. I'm hoping some of these symptoms ring a bell to someone and might give me a lead.

Thinking of replacing whole EI (to Pazon Sure-fire) but want to be sure it's necessary.

Any ideas? (I have tried copious swearing).


My Giddy Aunt!
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Re: Diagnosis please [Re: Uncle D] #745485
08/14/18 4:14 pm
08/14/18 4:14 pm
Joined: Aug 2001
Posts: 4,075
argyll. scotland, uk
gavin eisler Offline
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argyll. scotland, uk
EI for twins works better with 6 volt coils , try swapping your coils over and see if the rough running swaps sides.

Last edited by gavin eisler; 08/14/18 4:17 pm.

71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: Diagnosis please [Re: Uncle D] #745489
08/14/18 4:44 pm
08/14/18 4:44 pm
Joined: Aug 2005
Posts: 1,489
melbourne florida
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bodine031 Offline
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melbourne florida
I thing 6 ohms is max on EI twin ignitions. My Hornet has a BB with a 3 ohm HD single, dual tower, dual fire 12v coil, copper core plug wires w/ NGK 5 ohm caps and BP7ES for years works fine

Re: Diagnosis please [Re: bodine031] #745494
08/14/18 6:19 pm
08/14/18 6:19 pm
Joined: Oct 2008
Posts: 1,684
Canada
L
LarryLebel Offline
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Canada
The way you have it now the coils are only getting 6 volts. Wire them in parallel so they are getting 12 volts.


DO NOT DO THIS

Last edited by Jon W. Whitley; 08/14/18 11:38 pm. Reason: Incorrect Information
Re: Diagnosis please [Re: LarryLebel] #745496
08/14/18 6:29 pm
08/14/18 6:29 pm
Joined: Aug 2001
Posts: 7,549
scotland
triton thrasher Offline
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scotland
Originally Posted by LarryLebel
The way you have it now the coils are only getting 6 volts. Wire them in parallel so they are getting 12 volts.



I know nothing about Sparx, but I think you can’t do that with Boyer or Wassell electronic ignition.


Amateur Loctite enthusiast.
Re: Diagnosis please [Re: Uncle D] #745505
08/14/18 7:57 pm
08/14/18 7:57 pm
Joined: Mar 2005
Posts: 10,204
Boston, Massachusetts
J
John Healy Offline
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Boston, Massachusetts
Quote
The way you have it now the coils are only getting 6 volts. Wire them in parallel so they are getting 12 volts.


Ditto TT's comment


Re: Diagnosis please [Re: LarryLebel] #745509
08/14/18 8:27 pm
08/14/18 8:27 pm
Joined: Jun 2002
Posts: 10,178
Scotland
S
Stuart Offline
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Uncle D,

Originally Posted by LarryLebel
Wire them in parallel

NO!

Absolutely Do Not!



Like most e.i. for Britbikes, a Sparx e.i. has a single switched output to the coils. A '12V' Lucas or pattern coil draws between 3 and 4 Amps. If you connect more than one in parallel to the same switched output, Amps are added together. Like most e.i. for Britbikes, a Sparx e.i. cannot switch 6 to 8 Amps ...



Regards,

Re: Diagnosis please [Re: Uncle D] #745516
08/14/18 10:32 pm
08/14/18 10:32 pm
Joined: Jan 2014
Posts: 3,993
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NickL Online content
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Although the EI will work more efficiently with 2 x 6 volt coils or 1 x double ended 4 ohm one, it should be
perfectly ok with 2 x 12 volt coils on the road with standard compression.
If the old heap is progressively fouling up a plug then it's due to it burning oil or running miles too rich that side,
or low compression etc, putting the 6 volt coils on will help it to burn a crappier mixture but it's not really the answer.

The advice regarding the use of 2 x 12 volt coils in parallel is indeed incorrect with 90% of off the shelf EI's.
Consulting the manufacturers instructions is always the first 'go-to'. I know both Boyer and pazon say a minimum
coil primary of 3 ohms is required. Typically a 12 volt coil is around 4 ohms so 2 in parallel will give you around 2 ohms.
This is more of a load than the device can switch without eventually overheating. 4-5 ohms is good compromise
as far as the trade off between generated heat at the coil and spark energy.


Lamas are bigger than frogs.
No room for sanity here.
Re: Diagnosis please [Re: Uncle D] #745560
08/15/18 6:10 am
08/15/18 6:10 am
Joined: May 2004
Posts: 3,821
Sydney Australia
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BSA_WM20 Offline
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I ran my 73 ( 71 rebuild ) A65L for 6 years on & off using the original 12 V coils with a red Boyer ( was a while ago )
It ran fine around town but on long runs at high RPM the ignition would play up.
We are talking 80 mph or better.
Now the Boyer sat in the tool tray under the seat so not the best cooling wise.
Other than that there was no problems ignition wise other than when we were having a joint run wih the NOC & I was trying to keep the Commandos in sight so spent a lot ot time reving hard in 3rd on the twisties.


Bike Beesa
Trevor
Re: Diagnosis please [Re: BSA_WM20] #745569
08/15/18 8:15 am
08/15/18 8:15 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Uncle D  Offline OP
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Northern Territory, Australia
Originally Posted by BSA_WM20
I ran my 73 ( 71 rebuild ) A65L for 6 years on & off using the original 12 V coils with a red Boyer ( was a while ago )
It ran fine around town but on long runs at high RPM the ignition would play up.
We are talking 80 mph or better.
Now the Boyer sat in the tool tray under the seat so not the best cooling wise.
Other than that there was no problems ignition wise other than when we were having a joint run wih the NOC & I was trying to keep the Commandos in sight so spent a lot ot time reving hard in 3rd on the twisties.



Thanks Trev, this feels familiar. The bike was running beautifully...(in fact I had just overtaken a caravan and gesticulated for their pulling out in front of me)...I had been sitting on 65-70mph for about 40km when I just lost all power. This was not a gradual break-down ...there was no sign of it coming which indicates a failure of something. The original coils measured the same resistance and it is unlikely both would fail simultaneously. I only changed them as I had a new pair in the shed and wanted to eliminate them as an issue. Same with the battery...its wasn't brand new but held and put out 12+ volts. My EI sits on top of the oil tank so not the coolest location either.

I think it is simply the EI black box again (due to a combination of factors accentuated by a long hot run)... unfortunately I wont know for sure until I replace it.

PS: There is no way I would wire the two coils in parrallel...i do remember something from my year 11 physics class...actually, that is probably the only thing.


My Giddy Aunt!
Re: Diagnosis please [Re: NickL] #745570
08/15/18 8:17 am
08/15/18 8:17 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Northern Territory, Australia
Old heap?! Wash your mouth out. She is a beautifully restored machine that does not leak or burn oil..she just throws a hissy-fit every now and then. Actually I think God was putting me in my place as I was having waaaayyy too much fun!


My Giddy Aunt!
Re: Diagnosis please [Re: Uncle D] #745641
08/15/18 10:34 pm
08/15/18 10:34 pm
Joined: Jan 2014
Posts: 3,993
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NickL Online content
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My apologies old chap, no offence intended. I own and ride one of these old heaps as well.

The description of the on road failure indicates the progressive loss of power supply.
Maybe your alternator lead was the culprit and the battery was being continually drained.
The dying out of the engine, the kicking back on restarting with the subsequent rough running
all point to a poor battery voltage/power supply.
If one plug is fouling more than the other then it has nothing to do with the EI, the EI just switches
the coils on and off same as your old points did, only it switches them both on and off at the same time.
With crap fuel now the ignition does need a bit more power and may not be igniting as well as it could be.
The fitting of a pair of 6 volt coils or a dual output 12 volt one would improve matters but it will impose
a larger load on the power supply.

Failure of the EI is normally total, no restart at all.
Sitting the box on top of your oil tank is not ideal but no real hardship for the EI especially as you were
switching a small 8 ohm load = less than a couple of amps. Losses across the output are typically around
1.8v so 1.8 x say 2 amps = 3.6 watts. Very little ignition box self heating.

Before scrapping the existing system i would first check out the battery and charging system, you may
be spending money unnecessarily replacing the ignition.

Nick


Lamas are bigger than frogs.
No room for sanity here.
Re: Diagnosis please [Re: Uncle D] #745661
08/16/18 3:11 am
08/16/18 3:11 am
Joined: Mar 2006
Posts: 1,351
Magnolia, TX
htown Offline
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Magnolia, TX
The Boyer MKIII is very sensitive to low voltage. I've replaced a MKIII box with a MKIV with good results. Most of my bikes have Pazon Surefires which also tolerates lower voltages. Before you scrap your unit though you need to check the voltage supply at the white wire while putting a load on the system. Simply checking it with a voltmeter with no load doesn't tell you much. Procedure is explained here. See the section on checking for voltage drop, although the whole bit is worth going through.
http://vintagebikemagazine.com/technical-articles/Boyer-trouble-shooting/

Last edited by htown; 08/16/18 3:26 am.

1978 Bonneville T140E
1974 Trident
1970 BSA Thunderbolt
1971 Norton Commando
1972 Norton Commando
1973 Norton Commando
1974 Norton Commando
2004 XL 1200R Sportster

Everything will be alright in the end. If its not alright, its not the end.
Re: Diagnosis please [Re: NickL] #745676
08/16/18 6:56 am
08/16/18 6:56 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Uncle D  Offline OP
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Northern Territory, Australia
Originally Posted by NickL
My apologies old chap, no offence intended. I own and ride one of these old heaps as well.

The description of the on road failure indicates the progressive loss of power supply.
Maybe your alternator lead was the culprit and the battery was being continually drained.
The dying out of the engine, the kicking back on restarting with the subsequent rough running
all point to a poor battery voltage/power supply.
If one plug is fouling more than the other then it has nothing to do with the EI, the EI just switches
the coils on and off same as your old points did, only it switches them both on and off at the same time.
With crap fuel now the ignition does need a bit more power and may not be igniting as well as it could be.
The fitting of a pair of 6 volt coils or a dual output 12 volt one would improve matters but it will impose
a larger load on the power supply.

Failure of the EI is normally total, no restart at all.
Sitting the box on top of your oil tank is not ideal but no real hardship for the EI especially as you were
switching a small 8 ohm load = less than a couple of amps. Losses across the output are typically around
1.8v so 1.8 x say 2 amps = 3.6 watts. Very little ignition box self heating.

Before scrapping the existing system i would first check out the battery and charging system, you may
be spending money unnecessarily replacing the ignition.

Nick


yes you're right Nic...there are plenty of possibilities before a fried EI.

When I sat down in the comfort of the cave and started to look, I did find one of the alternator plugs undone; the trouble is that I'm not sure if this was the cause (as you described it) or was as a result of my roadside fiddling. There were a crew of mates looking over the bike, many with much more knowledge than me so it would be surprising if no-one spotted the unplugged wires...but it is still possible (especially given that the vast majority were Harley riders who were were more focussed on giving me crap for breaking down.

The battery is now brand new, as are the coils and I have given a fair bit of attention to electrical continuity and joints but have found nothing...yet.


My Giddy Aunt!
Re: Diagnosis please [Re: htown] #745677
08/16/18 6:58 am
08/16/18 6:58 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Uncle D  Offline OP
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Northern Territory, Australia
Originally Posted by htown
The Boyer MKIII is very sensitive to low voltage. I've replaced a MKIII box with a MKIV with good results. Most of my bikes have Pazon Surefires which also tolerates lower voltages. Before you scrap your unit though you need to check the voltage supply at the white wire while putting a load on the system. Simply checking it with a voltmeter with no load doesn't tell you much. Procedure is explained here. See the section on checking for voltage drop, although the whole bit is worth going through.
http://vintagebikemagazine.com/technical-articles/Boyer-trouble-shooting/

Thanks Htown
I found and printed that article last night and will work through it on the weekend. Although my EI is a Sparx, I expect that the differences are few and far between.


My Giddy Aunt!
Re: Diagnosis please [Re: Uncle D] #745712
08/16/18 1:24 pm
08/16/18 1:24 pm
Joined: May 2013
Posts: 4,952
Rotherham - S. Yorkshire
Allan Gill Offline

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Rotherham - S. Yorkshire
However you refrence the bike (old heap or beautifully restored machine) a non running bike is that regardless and the principles of how it runs doesn't change either...


Simple thinking though... and you have the ideal situation.. As if it is running on one cylinder then it can only be the things which are not common that are causing fault....


2 cylinders (one giving fault)
1 carb supplying both pots
1 ignition supplying both pots

so in different, they have their own spark plugs (change these before anything)
they have their own HT wires and leads (check these next)
They have their own set of valves (check these after that)
and they have their own exhausts, however unless a wombat has climbed up there, then I doubt that ones the problem.


beerchug
Re: Diagnosis please [Re: Uncle D] #745768
08/16/18 10:20 pm
08/16/18 10:20 pm
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Posts: 3,993
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NickL Online content
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Apparently the Sparx EI's do suffer with problems associated to the connections on their stator disc.
The connection terminals are 2 screws which are soldered to pcb tracks onto which the wound pick-ups
are fitted. Several people have indicated that the screws break out of the board or tear the tracks.
Personally i find this a little strange and would have thought the termination method is quite satisfactory,
but these are genuine reports from users. I have never actually examined one to be able to comment
but looking at the fitting instructions they seem OK.
The working voltage is specified as 10-15 volts so the battery would need to be pretty flat to inhibit
starting/running.


Lamas are bigger than frogs.
No room for sanity here.
Re: Diagnosis please [Re: NickL] #745919
08/18/18 11:22 am
08/18/18 11:22 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Uncle D  Offline OP
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Northern Territory, Australia
Righto, I've been over this thing so many times that the original symptoms are probably not much use.

New battery. No voltage lost in ignition circuit (new ignition switch)
New resistor plugs. Continuity in leads.
Continuity between stator plugs and EI. Resistance across stator plugs is 140 ohms. Wiring looks solid. Rotor is not slipping. Nothing seems to have moved since it was running well.
Alternator rotor is new and charging at 13.8v (I measured this when I managed to start it with mate's Boyer...more luck than anything).
New coils (12v in series). Resistance across single coils...both 4.5ohms...9ohms across the two.

Here are the current symptoms.
Farting /backfire while kicking over...wants to start but won't.
I currently don't have the air filter on (pancake style) to allow access to wires...I know this will richen the mixture but surely can't be causing these symptoms?

The fact that I've got spark at all must mean the EI unit is OK....right?

So the place to look is poor connections and certainly some of those around the coils could be better...that's my next focus.

Any suggestions?


My Giddy Aunt!
Re: Diagnosis please [Re: Uncle D] #745921
08/18/18 11:29 am
08/18/18 11:29 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Northern Territory, Australia
Ok here's a random thought.

Before the run on which I encountered the problem, I adjusted the tappets. I had the correct gap specifications and didn't over-tighten (slight grip on the feeler gauge).

The head had recently been professionally refurbished (valve guides, seats...even had seals added).

Any chance these symptoms are associated with something letting go in the top of the engine?


My Giddy Aunt!
Re: Diagnosis please [Re: Uncle D] #745925
08/18/18 12:13 pm
08/18/18 12:13 pm
Joined: Aug 2015
Posts: 1,244
Bolton Lancs UK
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Andy Higham Offline
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Bolton Lancs UK
Check the tappets again
Most ignition problems are either carb or mechanical related


BSA B31 500cc "Stargazer"
Greeves 200cc "Blue Meanie"
Greeves 350
Greeves 360 Challenger
Suzuki GSX1100 EFE "Sorcerers Apprentice"
GM500cc sprint/LSR bike "Deofol"
Jawa 500cc "Llareggub"
2003 Aprilia RSV Mille "Lo Stregone"
'35 OK Supreme
'36 OK Supreme
Re: Diagnosis please [Re: Uncle D] #745928
08/18/18 12:58 pm
08/18/18 12:58 pm
Joined: Jun 2002
Posts: 10,178
Scotland
S
Stuart Offline
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Scotland
Hi,

Originally Posted by Uncle D
I currently don't have the air filter on (pancake style) to allow access to wires...I know this will richen the mixture but surely can't be causing these symptoms?

Lack of an air filter without any other carburation changes normally weakens the mixture (more air). Could be giving the symptoms, especially in combination with something else.

Originally Posted by Uncle D
Farting /backfire while kicking over...wants to start but won't.

Can be a symptom of bad timing. Have you used a crank locating tool to find 38o (or whatever) BTDC and you're sure it was 38o (or whatever) BTDC, not TDC?

Don't know if Sparx e.i. has the same problem but Bransden have long had the problem of the odd "Stator Plate" wired incorrectly - when the Black/White and Black/Yellow wires are connected apparently correctly, the connections on the Stator Plate are actually reversed electrically and the timing is out wildly ... facepalm

Originally Posted by Uncle D
No voltage lost in ignition circuit (new ignition switch)

One way of being sure is make up a wire to connect battery -ve directly to the "Transistor Box" White wire (assuming standard 'positive earth'). Put a fuse in this wire in a position where you can access it sitting on the bike, because it's the only way of stopping the engine - ignition switch or kill switch won't. Also insulate the end of the standard White or White/Yellow wire from ignition switch or kill switch.

Also, how is are the Sparx Transistor Box and the coils series earthed? Lucas believed using random bits of bike was a crap idea long before e.i. was invented, I was advised against it by John Carpenter, whose Mistral Engineering company handled all sales and warranty work for Lucas Rita e.i. Boyer-Bransden/Sparx/Wassell e.i., I've always connected the Transistor Box Red wire directly to battery +ve (extending the Box wire if necessary) and the coils' series either also to battery +ve or something on the engine, with a wire connection between engine and battery +ve also.

Originally Posted by Uncle D
The fact that I've got spark at all must mean the EI unit is OK....right?

It's much of the battle, but the Box triggering the spark at the right time in suck-squeeze-bang-blow is another necessity ...

Originally Posted by Andy Higham
Check the tappets again

+1.

Hth.

Regards,

Re: Diagnosis please [Re: Uncle D] #745936
08/18/18 3:10 pm
08/18/18 3:10 pm
Joined: Mar 2006
Posts: 1,351
Magnolia, TX
htown Offline
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Magnolia, TX
I had a Sparx that the black white and black yellow wires were wrong. Would start but barely run. Switched them around and ran okay. Eventually binned it and bought a Pazon Surefire. Not impressed with Sparx quality at all.


1978 Bonneville T140E
1974 Trident
1970 BSA Thunderbolt
1971 Norton Commando
1972 Norton Commando
1973 Norton Commando
1974 Norton Commando
2004 XL 1200R Sportster

Everything will be alright in the end. If its not alright, its not the end.
Re: Diagnosis please [Re: Stuart] #745981
08/18/18 10:23 pm
08/18/18 10:23 pm
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Northern Territory, Australia
This bike has run very well with the stator plate wires in their current position, new alternator rotor and timing set up. This is all still firmly mounted and wires intact so I don't expect anything has changed here.

The + terminal on the second coil is earthed back to the battery + , as per the Sparx installation instructions. This is the same terminal as used by the EI red wire so I assume this is how the box is earthed.

I have read that it is recommended to earth the engine to the battery? I currently have 3 red wires coming out of the loom that are earthed (together) at the battery + and then the battery + to the frame (small clean lug under the seat). There is also an earth at the engine brace bolt under the steering head (shared with the Zener diode heat sink) which leads into the headlight. I assume this is the earth connection between the engine and battery. Do people rely on the brace providing the earth connection to the engine or should I extend the earth wire to the engine (at the other brace bolt) directly?

I can't see any other dedicated earth wires runnng from the engine to the battery +. Are there other locations people use to earth the engine to the battery?

If something had let go in the rocker box, surely I would have head something when the bike lost power....nonetheless, while the tank is off I will have a look.

I will continue to replace all spade fitting to ensure good connections and then put the air filter back on and give it a kick. I can't help thinking that this is something very simple (or a combination thereof).


My Giddy Aunt!
Re: Diagnosis please [Re: Uncle D] #745983
08/18/18 11:14 pm
08/18/18 11:14 pm
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NickL Online content
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NickL  Online Content
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It seems in this case you may have a dud ignition module. It's quite unusual but not unheard of. They normally fail completely rather than as yours has.
The only real final test is to substitute another one...............bloody nuisance and impossible for most people without buying another kit.
You would need to have valve/valves sticking open to give you the backfiring etc you are getting if the ignition unit you have is healthy.

An engine earth is a good idea though, you can use a small ring lug onto the screw that retains the engine chain guard
above the gearbox sprocket. It's easier than removing the front brace etc.


Lamas are bigger than frogs.
No room for sanity here.
Re: Diagnosis please [Re: NickL] #746028
08/19/18 9:11 am
08/19/18 9:11 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
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Uncle D Offline OP
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Uncle D  Offline OP
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Northern Territory, Australia
Checked tappets today...exactly where I left them (.008 inlet & .01 exhaust...slight grabbing on the feeler). All springs move up and down as they should.

Used an Allen key in timing hole and the rotor mark lined up with the timing pin as did the indicator screw and hole on the stator...nothing had moved.

Replaced all spade connectors on coils and replaced air filter.

Removed and blew out the pilot jet (AMAL Premier)... again as I can't get an idle. Set the carb back to default tune (air 1.5 turns out) and turned up the throttle stop.

Checked continuity (good) and resistance (none) the in leads.

Bowl is filling with fuel

She wants to start both with the existing Sparx EI and with a Boyer MkIII module...but backfires with almost every kick. Boyer seems to get a slightly better response but I may just be imagining it.

It ran for a little bit and had warm air at both exhausts ( but not enough for any tell-tales on the plugs). Running really rough, would not idle and did not like any throttle.

I can't help thinking this is something simple. Not overly difficult confident about the leads just because of the screw-in cap design...but they show continuity.

The only other thing I have not studied in detail is the stator as it has not moved, shows correct resistance and continuity to the EI.

My next step will be to remove the coupling plug between EI and wiring in case there is a poor connection that I can't see /feel from the outside.

Frustrating...but that's Old bikes.

(Ive got a 58 Super rocket that is new to me sitting in the shed waiting on a box of parts from NZ so I would like to get this PIA out the way before I launch into the next)!


My Giddy Aunt!
Re: Diagnosis please [Re: Uncle D] #746040
08/19/18 12:24 pm
08/19/18 12:24 pm
Joined: Aug 2001
Posts: 4,075
argyll. scotland, uk
gavin eisler Offline
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gavin eisler  Offline
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argyll. scotland, uk
The original symptoms suggest a disconnection in the power supply to the EI unit, I have had exactly the same when the ignition supply fuse ( non stock wiring) blade connector rattled loose, easy fix in my case.

For your fault I would try a hot wire , by pass the ignition switch and see if this improves things, if so the ignition switch contacts are the source of your problem, if you have a meter set to low ohms you can check the switch function by metering across the terminals and operating the switch, it should break to infinity and close to almost zero ohms, any fluctuation or non repeatability of the closed switch readings means a fail.

Edit, its a new switch, still worth checking though.

Last edited by gavin eisler; 08/20/18 9:13 pm.

71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: Diagnosis please [Re: Uncle D] #746092
08/19/18 10:18 pm
08/19/18 10:18 pm
Joined: Jan 2014
Posts: 3,993
Aus
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NickL Online content
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NickL  Online Content
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You've tried a substitute Boyer box on it? Should be ok with the sparx plate, both use around 120 ohms on the stator.

Only other thing i can think is AC is getting through from the alternator (dud rectifier) but that would stuff your battery very quickly.
Gavin's suggestion is a good one, just use the battery wired direct to the coil and ignition. No alternator/rectifier or any other connections.


Lamas are bigger than frogs.
No room for sanity here.
Re: Diagnosis please [Re: Uncle D] #746124
08/20/18 4:25 am
08/20/18 4:25 am
Joined: Aug 2001
Posts: 133
Anchorage Alaska USA
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Mitch Offline
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Anchorage Alaska USA
double check the ignition timing... like the whole procedure for the setup.

Re: Diagnosis please [Re: Uncle D] #746199
08/20/18 8:27 pm
08/20/18 8:27 pm
Joined: Aug 2001
Posts: 4,075
argyll. scotland, uk
gavin eisler Offline
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gavin eisler  Offline
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argyll. scotland, uk
Just to add a bit more sauce to the pot, Before my Boyer shed its power supply , it had been dangling by its leads, for how many miles dunno? loads probably, the velcro had let go, bouncing around behind the side panel. Once the connection was sorted , back to normal, Boyers are pretty tough. My 18 year old Boyer is still happily firing NGK plugs ( all be it through new 6 volt coils) which were rescued from the bin in the bike shop 8,000 miles ago, discarded as diesel fouled . The Boyer I have is a red one Mk IV maybe.
I am on my 3rd ignition switch since new ( presuming it had its original when I first got it)


71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: Diagnosis please [Re: gavin eisler] #746499
08/23/18 8:59 am
08/23/18 8:59 am
Joined: Jun 2002
Posts: 10,178
Scotland
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Stuart Offline
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Stuart  Offline
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Scotland
Hi,

Originally Posted by Uncle D
I have read that it is recommended to earth the engine to the battery?

If spark plugs are being fired by single-ended (one HT lead) coils, that circuit relies on good connections between the plugs ('earthed' through their connection to the engine) and the other end of the coils' HT windings. If an engine uses points, the ignition LT circuit also relies on a good electrical return path to battery +ve. If the engine has an oil pressure switch, that 'earths' through its mounting on the engine. Imho, it's good to have an obvious connection between engine and battery, rather than relying on connections between other components in between.

Originally Posted by gavin eisler
The boyer I have is a red one

MicroDigital. Mk.4 is still analogue so still Black box.

Hth.

Regards,

Re: Diagnosis please [Re: Uncle D] #746666
08/25/18 2:06 am
08/25/18 2:06 am
Joined: Jan 2014
Posts: 3,993
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NickL Online content
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NickL  Online Content
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I think the MicroDigital is the first of the u-processor based units Boyer made. Red box.
It had the idle stabilisation etc so i think it must be using a look up table, indicating it's a micro based system.


The Micro Digital ignition provides almost total control over ignition functions. In common with the MKIII, it offers electronic control of advance and retard functions. However, because the Micro Digital features a built in computer, the size of a postage stamp, it can make more than a million ignition decisions per second, to constantly monitor engine speed and time the spark precisely to suit. The programming of this micro processor also gives control over ignition coil energy, starting speed, tickover stabilisation and rev limits!

Last edited by NickL; 08/25/18 2:09 am.

Lamas are bigger than frogs.
No room for sanity here.
Re: Diagnosis please [Re: Uncle D] #748475
09/09/18 11:01 am
09/09/18 11:01 am
Joined: May 2013
Posts: 12
Northern Territory, Australia
U
Uncle D Offline OP
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Uncle D  Offline OP
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Northern Territory, Australia
So after replacing just about everything with no improvement I shelled out for a new Pazon.

As I was removing the old Sparx pick up plate, I noticed a small shard of magnet from the rotor had attached itself across the solder points on the underside of the plate, creating a short.

Bike is running beautifully on the Pazon and I have a new Sparx rotor on the way (£10) and will probably fit this EI to the A10 some time down the track.

You live and learn.


My Giddy Aunt!
Re: Diagnosis please [Re: Uncle D] #748483
09/09/18 12:10 pm
09/09/18 12:10 pm
Joined: May 2013
Posts: 4,952
Rotherham - S. Yorkshire
Allan Gill Offline

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Allan Gill  Offline

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Posts: 4,952
Rotherham - S. Yorkshire
I think you made the best choice, mine always seemed happiest with the bog standard pazon, even over its Altair bigger brother.


beerchug
Re: Diagnosis please [Re: Uncle D] #748502
09/09/18 3:26 pm
09/09/18 3:26 pm
Joined: Aug 2001
Posts: 4,075
argyll. scotland, uk
gavin eisler Offline
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gavin eisler  Offline
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Posts: 4,075
argyll. scotland, uk
Interesting fault, you got there in the end, well done. One to remember.


71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
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