Hi Norman, when I made my points and coil setup I machined the shaft to take a mag ATD. It should last forever driving a points cam. Cheers, Stu.
Misc: Everything Else Starting Problem - Series 'C' BIG Single
- Thread starter Jez Nemeth
- Start date
HI Stu, good point. I'm not sure that Jez has any access to machining facilities but if he could get a distributor from somewhere he would be most of the way there. The engine he has should be an interesting project.
Got a 14mm chainsaw decomp on a cable fitted through second plug hole (nice to retain the original lever), rubber non-suppression plug cap too. So it's down to kick technique and that spark.
You're totally right Norman, would need to get any parts accurately machined by an expert -mine is a very inaccurate 20's Drummond round bed... presently have the BTH FM1C electro-ignition and a KF1 Lucas (without adt/fibre wheel) -both fully functional. The electrical system is Alton -12v negative earth.
One point raised that has been a consideration in the back of my head -advance/retard degrees and the longer stroke, if fitting a newer system this may not be an issue, stroke is an 1" longer than standard -easy check on degree wheel from TDC.
You're totally right Norman, would need to get any parts accurately machined by an expert -mine is a very inaccurate 20's Drummond round bed... presently have the BTH FM1C electro-ignition and a KF1 Lucas (without adt/fibre wheel) -both fully functional. The electrical system is Alton -12v negative earth.
One point raised that has been a consideration in the back of my head -advance/retard degrees and the longer stroke, if fitting a newer system this may not be an issue, stroke is an 1" longer than standard -easy check on degree wheel from TDC.
My first bike was a C11 and that had distributor ignition. The C11G, C12, >>> had no distributor. As Timetraveller says the distributors are going to be hard to find.
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Might start with the 'Distributor doctor' I think -likely very busy chap, but may have just the thing, my knees won't take any more 'testing'... The back story -needed a project to bury myself with after a family bereavement while dealing with probate and all that jazz...Bill Thomas put me onto it ( thanks mate, just what was needed at the time), It's Renwick's ex-development engine for Epimetheus, one half effectively, running on alcohol -talked to Ed Wallbank about it at Bristol & Bath, finding out it had ran with Goldstar valves and gas flowed to 40mm for one, and a number of other mods etc... lots missing, but doable. So started making and fettling a few bits, machining/casting etc... We like a challenge.
So the bike looks pretty much standard, until you look closely...no special, just wanted something to keep up with traffic on the motorway really, and if it all went south, weld up a frame for sprinting as a respectful acknowledgement of John's work living on -which was the other thought.
So the bike looks pretty much standard, until you look closely...no special, just wanted something to keep up with traffic on the motorway really, and if it all went south, weld up a frame for sprinting as a respectful acknowledgement of John's work living on -which was the other thought.
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Although I fully appreciate that John Renwick was not attempting to kickstart this behemoth, does anyone know what ignition device he was using.
To my mind it is not the best idea to use a magneto atd with ordinary points! Because of the magnetic resistance,the coil tends to "stick" between the magneto and because of that the timing is forced to retard.Especially when you start the engine the timing is retarded to the maximum because of the "sticky" magneto.Not so with points here the retarding is only by the springs of the atd unit. I hope you understand what I mean.not so easy for my to find the right words Erik
Forgive lack of knowledge here, just scouting around the problem and discounting the obvious -would the 12v Pazon Smartfire unit needing a battery supply offer another solution possibly, rather than the self sparking BTH electro?
Jez, when I bought the ex-Cecil Mills twin years ago it was a 6 volt system with a special coil that Cecil had either had made or bought somewhere. If I disconnected the output wire from the coil and turned the engine over I could get a 2" (two inch) long spark which wriggled its way out of the coil and found an earth where ever it could on the crank case. The coil was mounted as per series 'D' on the side of the drive side crank case. When I changed to 12 volts I could never find a coil to give such a spark. The reason for this story is to encourage you to consider coil ignition. Any system which relies on the speed at which you can spin the engine is going to be problematic with that engine. You don’t even have to spin the engine with coil ignition, just open the points with an insulated screwdriver.
When it comes to timing a degree plate and a method of putting something down the plug hole to stop the engine rotating is all that is required. The stroke does not come into it.. Just turn one way, gently, until the engine stops. Rotate the other way, gently, until it stops and then split the difference and that is TDC.
When it comes to timing a degree plate and a method of putting something down the plug hole to stop the engine rotating is all that is required. The stroke does not come into it.. Just turn one way, gently, until the engine stops. Rotate the other way, gently, until it stops and then split the difference and that is TDC.
So a distributor, any that spins the right way- say a D series, removing one rotor contact in cap, with 'adjusted' internal ATD to match Adv-rtd of a single, good coil and 12v neg could be a way forward? BSA C12 distributors are hen's teeth by all accounts...