Author Topic: I've killed my spark and fuel supply - how on earth...?  (Read 2400 times)

Offline CrispinA10

  • Moving Up
  • **
  • Join Date: Mar 2015
  • Posts: 63
  • Karma: 0
  • 1960 Super Rocket in RGS spec. 1965 Enfield GT
1960 A10 Super Rocket RGS replica has been running beautifully for last few hundred miles - sweet as a nut, no oil leaks and all just lovely. About 300 miles back developed a slight stutter on acceleration, so I gently filed some light pitting from the points and that sorted it. Last night on way home from work noticed similar slight stutter (which had been increasing over week or so) so this afternoon used my day off to whip the top off the Lucus K2F and dress the faces of the points again. There was some slight pitting which I smoothed off.
Put it all back together, kicked it over and - nothing. Took off magneto cap again but all looks fine. Put it back, kicked it over, but still nothing. Took out the plugs and kicked it over to see if there was a spark. There wasn't - but the plugs were completely dry. Tickling the concentric gives a healthy stream of petrol, but it doesn't seem to be getting through to the head. If I put my thumb over one of the plug holes and kick it, there isn't even a whiff of fuel. Drained the carb chamber, checked for gunge but all clean. It is a new Amal (Wassell) 930R and has been running fine. Clearly the fuel and spark issues can't be connected - can they?
Is there a well known daft-as-brush cock up relating to K2Fs and the points? I didn't take them out so cannot have anything the wrong way up or missing an insulation collar like the points I am familiar with.
Any suggestions gratefully received.

Online Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 5680
  • Karma: 30
I'm sure one of the forum trusty's will pop up shortly but I suggest that the lack of fuel and the no spark cannot be related. If you had a spark I would suggest squirting a little petrol into the plug holes, refitting the plugs and seeing if the engine fires at all. Focus on one thing at a time.

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1458
  • Karma: 20
You may have left grit or grease between the points.

Wet them with petrol and drag a clean piece of paper through them.

Offline CrispinA10

  • Moving Up
  • **
  • Join Date: Mar 2015
  • Posts: 63
  • Karma: 0
  • 1960 Super Rocket in RGS spec. 1965 Enfield GT
Logical ideas - and quite right, I need to focus on one problem at a time in case I create another. Poured a little petrol down both plug holes, kicked over, but nothing. Cleaned the points with a petrol-soaked bit of paper and again, nothing unfortunately.
Although the battery is pretty well flat, the bike always fires first or second prod, so there is something distinctly wrong somewhere...

Offline groily

  • Wise & Enlightened
  • *
  • Join Date: Jul 2007
  • Posts: 1049
  • Karma: 17
    • www.brightsparkmagnetos.com
What sort of contact breaker have you got? Sounds to me as if the total sudden loss of sparks is a low tension problem, and if you have the later steel backplate cb assembly it is possible that the spring on the opening point is kissing the camring following adjustments and cleaning? If it is, there'll be no sparks as the opening point is connected to low tension live on the coil and it will be shorted out. Happens often. There needs to be a good few thou clearance all the way round as the cb rotates. Occasional kissing could also explain prior misfiring, typically on one cylinder only (although a few other things could too of course). Adjustment of spring position is provided for by a slot in the springs where they are anchored to the little ear that sticks out from the backplate - a tighter arc will avoid anything touching.
If you've got the earlier brass backplate though, a kissing spring won't have this effect as the opening point is earthed anyway, and it is rare to develop a total loss of sparks after fiddling.
If you're getting regular pitting on the points after not much use, then you could be faced with a failing condenser, but you'd expect difficult hot starting as another effect of that - and you wouldn't expect total loss of everything.
It's weird that there's no obvious fuel flow either - but I suspect if the sparks came back, the thing might run, as sometimes plugs don't look very wet even when all is well. I'd try to get the sparks back first, before playing with anything else, as it won't run whatever you do if there aren't any!
(Nothing to do with a flat battery by the way - that's the beauty of the mag, doesn't need it.)
Bill

Offline CrispinA10

  • Moving Up
  • **
  • Join Date: Mar 2015
  • Posts: 63
  • Karma: 0
  • 1960 Super Rocket in RGS spec. 1965 Enfield GT
Not sure which backplate I have (I'll go and have a look and take a picture if possible) but didn't think I had a condenser. That's the first thing I thought of as just about every ignition problem I have had with bikes and cars has boiled down to a blown or failing condenser. Can't see anything resembling one inside the magneto. Ah. Just looked at manual and it says it's inside the armature - er, where's that? I'm looking at the Haynes manual illustration of the armature, which I assume sits inside the mag, but there is no sign of a condenser.
Having said that, it was running fine yesterday (apart from slight stutter) so not sure why cleaning points would have any effect on condenser, which I can't even see, let alone bugger up by fiddling.
Right - picture attached. Looks like steel backplate rather than brass.  Think I will order a condenser straight away, as based on experience if it hasn't packed up yet, it probably will soon. I always used to carry a spare when riding the Enfield, although I understood that electrical system slightly better. I was surprised to see that the BSA one turned around the cam rather than being fixed. All part of being a twin I suppose...

Online Billybream

  • Valued Contributor
  • ****
  • Join Date: Jan 2012
  • Posts: 488
  • Karma: 5
The condenser is buried inside the magneto, replacement is not a simple task, its normally undertaken during magneto overhaul by a specialist.
If you want to go down the DIY route it might be best to try the Easy Cap solution supplied by Bright Spark Magneto,s, Easy Cap is a modern type of capacitor and mounted close to the points. Your points are the steel back version.
1960 Super Rocket, owned since 1966, back on the road 2012 after being laid up for 29yrs.

Online chaterlea25

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 3108
  • Karma: 45
Hi Crispin,
Another possibility is  the cam ring has popped out and turned, with  some types of end cover this is more common than others  *conf* *conf*

John
1961 Super Rocket
1963 RGS (ongoing)

Online KiwiGF

  • Last had an A10 in 1976, in 2011 it was time for my 2nd one. It was the project from HELL (but I learned a lot....)
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 1386
  • Karma: 12
The points leaf spring in the pic does look very close to the cam ring.....is that normal? Can it be adjusted to be further away? Are there any signs of it rubbing on he cam ring, difficult to see if so in the pic.
New Zealand

1956 A10 Golden Flash EA7-168x, CA10 913x, left BSA together for Liverpool, 5th Dec 1955.

1949 B31 rigid “400cc hot rod” (favourite bike)

1949 C11 rigid, but why!!! (cos it was cheap)

1937 B21, missing parts so mission impossible?

1952 Armstrong Siddeley Whitley for rainy days (with wife).

GL1800 Goldwing not sure why, maybe cos it always starts

Offline groily

  • Wise & Enlightened
  • *
  • Join Date: Jul 2007
  • Posts: 1049
  • Karma: 17
    • www.brightsparkmagnetos.com
Looking at the pic, I don't THINK the camring has jumped out judging from the fact it's still pretty flush with the housing. The ring is located by a screw-in pin which engages with a notch and said pin should be in said notch.
The spring looks close to the lower lobe of the cam, at about half past five in the pic - but the spring's arc also looks as close as can be to its smallest judging from the amount of 'tail' extending beyond the securing ear where the little screw is. Probably OK - but worth making quite sure that it isn't touching there or on the opposite, upper, ramp of the camring, because if it does it's a definite reason for a problem.
All 'K series' mags have camrings rather than a central cam. The system works fine as a rule, especially on mags like yours with a fixed camring.
The condenser is indeed on the inside as mentioned, in a recess at the drive end of the armature next to the coil. About the most awkward place it could be! It is wired between the 'nut' at the bottom of the centre screw that holds the cb unit on (low tension 'live') and the body of the magneto ('earth'), so in parallel with the contact breaker, which is what we need. It is unlikely that anything has happened to it that would kill all sparks all of a sudden though - usually they deteriorate and you get misfiring, pitted points, and poor starting when hot, which gets progressively worse.
Might be worth checking that when the points are 'closed' they really ARE closed and making good contact. It's delicate with a meter, but if you have a sensitive one you want to see 0 ohms across the points, shut, and about 0.5 ohms across them, open. That half ohm is the resistance of the primary winding of the coil, so it's not like measuring across the points on a battery & coil ignition system where you'll see 'Open Line' when they're open. Also worth checking that the brush or brass strip in the cb end cover (for stopping the engine) isn't touching anything except the head of the centre screw.
 
Bill

Online metalflake11

  • Resident Legend
  • *****
  • Join Date: Aug 2012
  • Posts: 579
  • Karma: 9
Re: I've killed my spark and fuel supply - how on earth...?
« Reply #10 on: 15.07. 2016 23:51 »
Are you sure the points are still closing when they should?
England N.W
1960 A10
England

Online duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4510
  • Karma: 40
Re: I've killed my spark and fuel supply - how on earth...?
« Reply #11 on: 16.07. 2016 03:01 »
 
 In case I missed something, and at risk of sounding really dumb *eek*, but does it by any chance have a kill switch that you've 'forgotten to flick on' or a button ? (it's probably the oldest catch-out in the book)
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline CrispinA10

  • Moving Up
  • **
  • Join Date: Mar 2015
  • Posts: 63
  • Karma: 0
  • 1960 Super Rocket in RGS spec. 1965 Enfield GT
Re: I've killed my spark and fuel supply - how on earth...?
« Reply #12 on: 16.07. 2016 08:54 »
Yes , there is a kill button, opposite the horn button on the dip switch. I should have thought of that. Have to go out in four minutes, but this evening will give that a good wiggle. I certainly used it to stop engine when I came home on Thursday, which is the last time I saw a spark. That would be a wonderfully simple and logical solution - and somewhat easier than stripping down a mag to replace condenser. The points do open and close fuller as far as I can tell with a feeler gauge, and was running fine before, so I don't think anything has jumped or slipped. Is there a quick way to disable kill switch - can I simply disconnect a wire?

Online duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4510
  • Karma: 40
Re: I've killed my spark and fuel supply - how on earth...?
« Reply #13 on: 16.07. 2016 10:42 »
 Disconnect it at the Maggie end or just leave the cover off (saves  having a bare wire to short out  *eek*),  but be ready to pull the plug leads if you need to stop it
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8021
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: I've killed my spark and fuel supply - how on earth...?
« Reply #14 on: 16.07. 2016 12:44 »
Leaving the cover off may lead to the camring coming out. If there's a joiner in the wire between the mag and switch disconnect there or at the mag. Replace that wire with one with a bare end. Touch the bare end to the motor to stop it.
Cheers
'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
Australia
Muskys Plunger A7