Point ignition wiring help

[Skunk]

I need help. Points system on the bike and I know fark all about those. All I need is a spark at the plug - don't need anything else.

Google search said: "sorry - before my time" or some such.
I don't know what in the system works and what doesn't... so I figure the best way to start is wire it up correctly.

I'm guessing it's 6 volt (due to it's age - 1972-74ish) and I seem to have guessed right about the black being Earth as when it's kicked over all the others (except Green) produce 3ish volts. The Green is the neutral switch.

Here's what I have coming out of the flywheel:

[Motu]

Is this on a Spragthorpe?

[hmmmnz]

if you get stuck, i could come round and take a looksy for ya,
what bike is it??

[craisin]

google kettering system:Oi: sounds like a yamaha=black earth Its simple a wire from the + red side of the battery goes to the ignition switch and then on to the + side of the coil. The -- negetive side of the coil has a wire that goes to the points. :rolleyes:pretty simple to me. If you want to use a bigger car coil it would pay to use a little heavier copper wires save oxerworking the originals

[craisin]

google TAC or transistor assisted contacts too

[ajturbo]

use a bigger hammer.. that may help?

[Skunk]

Is this on a Spragthorpe?Kawasaki F6


google kettering system:Oi: sounds like a yamaha=black earth Its simple a wire from the + red side of the battery goes to the ignition switch and then on to the + side of the coil. The -- negetive side of the coil has a wire that goes to the points. :rolleyes:pretty simple to me. If you want to use a bigger car coil it would pay to use a little heavier copper wires save oxerworking the originalsNo battery. I have been told it can work without one (which is what I would like).


google TAC or transistor assisted contacts tooWill do.

[Ixion]

You sure you got cb points in there ? Looks like a standard TAC flytwheel magneto to me. Which is a whole different ball game to a Kettering system. Car coils won't work (probably) for a start.

In theory this (attachment) is what an F6 Kawa should have

[Skunk]

You sure you got cb points in there ? Looks like a standard TAC flytwheel magneto to me. Which is a whole different ball game to a Kettering system. Car coils won't work (probably) for a start.

In theory this (attachment) is what an F6 Kawa should have
That's wot I got! TAC. Thanks Ixion

Now, how do I wire it up? Do I need a battery (prefer not), which wire does what?

I see that '5' is the ignition coil so that's a clue to clueless me I guess.

[Ixion]

Nope. No battery needed. It's a magneto.

Basically , the magneto (the bit behind that big circular lump in the picture) holds several coils. Two big fellows (usually two) for lighting, you can rip those out if you want to , might save 0.001 hp. And a small coil called the primary coil, which generates electricity to power the main coil (the one mounted on the frame somewhere). Instead of a battery powering the coil And a little tiny coil, probably just looks like a little box, that is the trigger to say the piston's in the right place.

The lighting coils would originally have gone to the rectifier/regulator, but you can ignore them

The other two are the important ones

Depending on your electrics design (and unfortunately, unlike Kettering it's NOT standard), the one from the trigger will go to a little box (may only be about the size of a matchbox, the TAC unit, somewhere on the frame. The other important wire, from the primary coil will go (maybe indirectly via a kill switch or something) to EITHER the TAC unit, or direct to the main coil. Try looking around for matching colour wires on either of those.

Also find the main coil and see where the wires on it go to.

[Skunk]

Looks like I'm missing the TAC unit. That'll be why my 'logic' failed.

Thanks Ixion; great help to sorting this. I'm installing this engine in a different bike and only have the engine and the wires you see in the photo. I'll start hunting for the 'other' bits now.

[Ixion]

Nope. Belay that. I just looked at that diagram.I was wrong. It's not TAC. Not if that's the right diagram It's for a 71 model and DOES show cb points.

So the circuit is real simple.

Wire from the primary coil to one side of the coil. Other side of the coil is either earthed, and the other side of the primary coil goes to the CB points. Or the other side of the primary coil is earthed and the other side of the main coil goes to the points. No TAC needed. But around that period a lot of bikes changed from plain cb points to TAC.

It would probably help if you could get the flywheel off, then you could follow the wires, but that would need a suitable extractor.

[Skunk]

I have a suitable extractor. I was starting to doubt you too as I couldn't see a TAC in the bits of diagram I found (at the website the diagram you posted came from).

I will follow the wires to find the one/s I need. So it'll be wired like either the green or red below.

[Ixion]

Uh, not sure about your drawing

It'll be either classic Kettering:

Wire from primary coil (which replaces battery) to one side of coil (maybe through a switch). Other side of coil to points. Other side of primary coil earthed.

Or: The alternate sometimes used on magneto setups, cos it only needs a single wire

One side of primary to contacts. Other side to coil, and other side of coil earthed.

Either setup, the primary coil, the main coil and the points are all in series. The primary coil outputs a generated current to the main coil, through the points. When the points open the magnetic field collapses, inducing a HT pulse (the spark).

Check the primary coil . One side of it should certainly be coming out from the magneto. The other side may be earthed (1) above. Or go to the points, within the magneto (2) above. Or come out of the magneto, which would originally have been to an ignition switch/kill switch , and is effectively (1)

[craisin]

well a mate up north had a boat with a small Johnson outboard and it didnt spark no battery. And he didnt have $30 for a second hand coil :zzzz: so we took the existing wires off the points and wired up a car coil up to the points and a car battery that we put in the bottom of the boat:zzzz:he said if it went for 6 months he would be happy. 2 years later it still went :bash:at the end of the day some of us have done things in our lives. My experience with total loss systems come from the fact I built a C grade saloon car and the alternator was merely a fan belt tensioner. Get a black dog up you

[Ixion]

Yeah car coil is usually fine with points. Its only when bloody transistors and shit comes into it that it gets complicated.

I remember when there were only two types of coil . For EVERYTHING. Cars bikes boats planes whatever. Lucas for Briddish stuff. And AC-Delco for Yank stuff. Easy.

[craisin]

the brother from lyal bay has a link in his thread to another forum with a lot of wiring diagrams

[Skunk]

the brother from lyal bay has a link in his thread to another forum with a lot of wiring diagrams
Cheers - seen that and copied a few. I can get a bulb to glow with the LT side but no spark (coil comes from a running 6 volt bike).

[hmmmnz]

if you want me to come over at some stage and have a look,
im not too far away,
my little 120 also runs a 6 volt system so could try out the coil ect,

have fun

[Skunk]

if you want me to come over at some stage and have a look,
im not too far away,
my little 120 also runs a 6 volt system so could try out the coil ect,

have funThanks for the offer. I'll PM you if I get stuck. I'm going to follow one of the wiring diagrams you posted. Only has two wires I need so what could possibly go wrong?

[hmmmnz]

lol, famous last words if i have ever heard em :D
have fun :D

[craisin]

Thanks for the offer. I'll PM you if I get stuck. I'm going to follow one of the wiring diagrams you posted. Only has two wires I need so what could possibly go wrong? you could get the wires wrong on the coil and you need a condensor to suit the coil

[Skunk]

OK, I've a spark but it's really random. I'm thinking I need to adjust the points a bit but have no idea how to do that on this thing. TDC I can't get at the points due to the flywheel... That the flywheel off and there goes the cam the points run on. I'm only used to cars when it comes to points so if anyone can help...

[hmmmnz]

you should be able to get to the points and adjust the gap through the hole in the flywheel,
the flywheel should have a mark for tdc and when it fires,
may be the points are a bit corroided and need a wee bit of a sand?

[Ixion]

Check that the flywheel is running true.

[Skunk]

Thanks guys.
Flywheel is off-centre by 0.5mm. I found the TDC 'mark' is not the TDC mark. I've now aligned it to true TDC and now can get at the points to adjust them. I've given the points a clean up and made a key for the flywheel :lol:
What would a standard gap be?

[hmmmnz]

0.3-0.4mm is the standard gap

[Skunk]

I'll see how good I am at setting that then.

[speedpro]

I used to change the timing little bits by altering the gap. It'll be a points magneto, they pretty well all were back then. The kill switch and ignition switch would have been in parallel with the ignition coil. Either kill or ignition switch would have shorted electricity to the ignition coil to ground to stop the motor. In these simple systems the spark occurs when the points open, just like a kettering system. To eliminate possible problems just run a wire from the generator coil straight to the ignition coil. The other side of the ignition coil will be connected to ground and the other side of the generator coil will be connected to the points and condenser. You need the condenser, not to stop the points sparking but to form a resonant circuit with the coils thereby enhancing the spark. Trash the wiring loom, you only need one wire.

Actually what you need is a good CDI ignition. Even on my first bucket, an AC50 back in '83, it was obvious that with any tuning that the ignition didn't hack it. I designed and built a battery powered, points triggered(with debounce circuit), CDI. It could throw a 15mm fat blue spark at the equivalent spark rate of a V8 at 10,000rpm.

[speedpro]

You'll know when you have the gap right as the "F" mark will line up when the spark fires. That's the only adjustment in stock form.

The correct coil will have "AC" on it, for AC magneto. A coil for a points or transistor assisted system will have "DC" on it and a cdi coil will have "CDI" on it. They are not interchangeable, for best results, ideally.

[Skunk]

Thanks Speedpro. I still have your ramp too. hmmmnz came round today and diagnosed several things a very short time.
• the points were broken
• the coil works
• the plug cap was a resistor one which wasn't helping
He's given me links the all sorts of things and been a great help.
Thanks heaps hmmmnz.

[hmmmnz]

i aim to please :D
love the buckets, they were awesome, good luck for next weekend,
gimme a yell anytime if you ever need a hand with anything

[speedpro]

Unless you have a great BIG FAT ignition system that throws serious current down the HT lead a resistor plug cap is not going to make any difference. E=IxR so the voltage drop can be calculated. If you have a system that delivers say 20mA to the plug and you have a 5Kohm plug cap the voltage drop will be 100V. The coil may put out 10,000V so the 100V drop is only 1%. If that 1% makes a difference . . . . . .

[hmmmnz]

that is indeed true, but resistive plug caps have a tendancy to blow the resistor,
1 less thing to worry about, the better i say

[speedpro]

All the resistor plug caps I have dismantled have had a little carbon rod inside. The only problem I have ever seen is that for whatever reason the little carbon rod ceases to be a snug fit inside the cap with the result that when tested with a multimeter with the usual very low voltage on the ohm scale it shows an open circuit. If you were to poke 10,000V into it the arc would just jump over the tiny little gap which has the effect of making the plug gap .002" bigger. It's a commonly made mistake measuring a plug cap with a multimeter and tossing it because it reads open circuit.

[craisin]

well done crew:wari:

[jonbuoy]

I thought the idea of resistor plugs was to give a longer spark duration?

[Skunk]

I thought the idea of resistor plugs was to give a longer spark duration?
No, they just stop radio wave interference.

[Skunk]

Well, got everything together but have a random spark. Could be (as Speedpro says) the CDI 6 volt coil.

The correct coil will have "AC" on it, for AC magneto. A coil for a points or transistor assisted system will have "DC" on it and a cdi coil will have "CDI" on it. They are not interchangeable, for best results, ideally.
Hmmm, don't have those marking on any of the coils... Anyone know what an RD400 has?

[speedpro]

I'm not 100% sure but I think if it isn't marked it'll be DC by default. It'll have slightly different reluctance to an AC coil but should be good enough to run the motor. I haven't tried that so can't say for sure.

[Ixion]

A CDI coil is unlikely to work on a magneto system. The CDI puts out several hundred volts to the coil, whereas the magneto puts out somewhere between about 6 to 30v

A DC coil (old fashioned car) should work OKish.

EDIT. When you say "random sparlk" do you mean that you have a spark on every revolution, but randomly as regards timing (ie sometimes at TDC sometimes at BDC and in between): or do you mean that there is a spark but not on every revolution ?

[Skunk]

I might try old of the RD400 coils then. I don't think I have any car coils around (and it won't be 6 volt anyway).

Random as in not every revolution. Seems the faster the revs the less likely the spark.

[speedpro]

Get a decent ignition you tight sod.

[Skunk]

Get a decent ignition you tight sod.
Thanks for the offer of a KX80 ignition for free, Speedpro. I was having trouble finding an affordable one.

I have a TF ignition lined up for it but first I want it running with the standard stuff (before I bring variables into it).

[hmmmnz]

you could also run it with out any generator and have a constant loss
system with a 12 volt battery, change the coils to 12v, and be done with it :D
you should get about 7 hours continous riding on 1x 12v 6ah battery
more than enough for any endurance race.

[Skunk]

Cheers hmmmnz. I've changed the coil to a 'what-the-fuck-is-that' 6 volter that I found in the bucket bits shed and now I have a nice big fat spark.

Loverly. Now the carb... :laugh:

[hmmmnz]

good shit thats what i like to hear :D
i hope you are gunna run with a filter, fuck having to buy larger jets and fluff about jetting,
my rotary valve bike doesnt like starting without the side cover on, once running, it seems ok though, and makes the coolest noise :D

[Skunk]

I'll run a filter - I don't have the cover. Find out tonight if it runs.

[Skunk]

Well, it has everything it needs - fuel, spark, timing - but no go. Will try again tomorrow before heading off to Hawkes Bay.

[hmmmnz]

whats the ring gap like??
is the plug getting wet??
as i said the rotary valve bikes dont seem to like to start with out a filter on them, they seem to need the resistance that it causes, try stuffing a rag around the carb (a clean one) to try and simulate having a filter on,
they also dont like having fuel dumped in the bottom end, and wont start with easy start or anything like that either.
are you getting any blow back from the carb when you kick it over??
the valve seal need to be good:D

fun times,
good luck with the racing tomorrow,
gimmee a yell if you want me to come over and have a squiz at the bike at some stage

[Skunk]

Well, I got it going. Squirted so fuel down the carb and away she went. Sounded pretty good too. So I took it to Hastings. Runs quite well for brief moments :Oops: First time I left pit lane and make it as far as the start finish line. Second time I made it further - all the way to turn one :killingme

Turns out the flywheel was free wheeling as soon as I back off the throttle :lol: Oh, well, live and learn. Easy fix for the next meeting.

Thanks to everyone for the help and advise. Cheers to you all.

[craisin]

so you left the keyway out:laugh:sounds like the kind of thing I am likely to do from time to time. good luck

[Skunk]

so you left the keyway out:laugh:sounds like the kind of thing I am likely to do from time to time. good luck
Nah, it sheared the key. I don't think the nut quite tightened on the taper before the thread ran out.

[craisin]

Nah, it sheared the key. I don't think the nut quite tightened on the taper before the thread ran out. hmm im sure the brother from lyall bay will give it the eye and come up with a cure. Just as well it happened at low speed. If you were flat knacker it would have been sadder to say the least. The rear brake drums on my old 55 vauxhall would shear the key and damage the slot and I had to get it machine out to suit a larger key. And the guys from the machine shop encouraged me tap the brakedrum on with a piece of 2 inch pipe and a sledge hammer so you didnt stress the threads out pulling it on the taper. You needed the pipe to keep away from the threads and the area that the nut seats on and a smaller hammer would not be able to hit it square. I hope for your sake the nut has stripped. :Oops::bash: Nowdays they have locktite

[hmmmnz]

i bought a wood drift key from the guys at shrodoco (http://www.schrodoco.co.nz/) on tory street in the city, $3 i think,
they have a whole box of them of different sizes,
the indian guy in there is great when it comes to getting bits, and gave a random like me very good discounts when i replaced all the bearings in my engine, about 50% cheaper than the bike shops. and he was helpful unlike those fuckers :D (apart from the bike shop in newtown, they have been good too :D)
as for tightening on the thread, thats why they have washers :D hehe

[Skunk]

Tony's Auto Centre now - and they don't seem to have any at the moment.
I don't think the nut tightened properly on the flywheel. It was tight but I suspect it was on the end of the thread. I'll lap the flywheel on and then fit a spacer to make sure it doesn't happen again.

[hmmmnz]

what really, i just got 1 about a month ago, and he had a whole box full of different sizes, who did you talk to??
dennis i think his name is, the indian looking guy is the best to deal with, the owner is a bit of a plonker,
what size do you need?? 3mm wide??
ill stop in tomorrow after work and have a word with him

[speedpro]

I had an engine with a BADLY corroded taper and a partly shagged keyway. I used Loctite bearing mount on the taper to eliminate any freeplay. Any nut holding one of these rotors in place should have a hardened washer under it. One of the best buys I have is my rattle gun. Bit of Loctite and spin it on with the rattle gun and it won't be coming off.

[Skunk]

ill stop in tomorrow after work and have a word with him
I have a key now - thanks anyway. They're just around the corner from my work too.

[pete376403]

I had a Kawasaki F9 Bighorn that used to shear the flywheel key, almost from new.
The key shouldn't play any part in stopping the flywheel from moving on the taper - it's only there to correctly locate the flywheel when it's put on.
I finally cured it by lapping the flywheel to the crankshaft taper with fine valve grinding paste. Once this was done and all the shit cleaned off with petrol, the flywheel went on, with a new woodruff key in place, the nut tightened to the correct torque and the flywheel never came off again.

I've also done this with Lucas and PAL magnetos on speedway motors

[Skunk]

Cheers Pete. I've lapped it with valve grinding paste and used a 'little' Loctite.
Used a fat washer behind the nut too. Cross fingers.

I knew what the key was for which is why I was happy with the one I made.

Looking at the tapers I think I may need to machine the crank and the flywheel at some stage. Either that or do a shit load of lapping!

I'll see what happens on the 1st March at Kaitoke.

[Kendog]

I'll see what happens on the 1st March at Kaitoke.

Why not try the unofficial Petone track in the weekend. It's going to be quiet given it's a long weekend and it's the sevens.

[Skunk]

Why not try the unofficial Petone track in the weekend. It's going to be quiet given it's a long weekend and it's the sevens.
Hush now! :shutup:

[craisin]

so if they are prone to shearing from new reducing the size by machining aint going to do jack. Lightening the flywheel may be a good idea.

[Skunk]

The taper was in a bad state, I just didn't realise how bad until I started lapping it in. I don't think they are 'prone' to shearing - just they can if things aren't right.
If I was going to 'hot' this motor up I would lighten the flywheel.

[craisin]

less spinning weight would make it less likely to spin on the shaft:niceone: and you dont have to split cases:weird:

[Skunk]

You're missing the point of this exercise.

• Don't spend money.
• Try the motor first.
• It'll never be a competitive engine - cast iron barrel, very little finning on the head etc.

Why would I spend time and money lightening a flywheel that has been fine for the last 35 odd years? I just didn't put it together very well.

[craisin]

:Oops:I assumed skunkworks was a million dollar bizness. Im just having you on as its obvious you dont have a parts motor to cannibalize.

[Skunk]

The Norf Welly Massif Skunkworks Bucket Factory (to give it its full name :laugh: ) is a negative balance business. All we have is shite no one else will touch.