Repair-Chat
This page is for any comments, pictures, stories or information you might want to impart to the site that don't necessarily
fit anywhere else on the website.
There are rules!
Primarily don't be rude, offensive or obnoxious, for more details CLICK HERE
See Older Posts
Ren - The Ed¹ said :-
Cheers Ian. I'd never really thought about the kind of paints used on what I might term as "old" machinery. There's an amazing amount of stuff available which I wouldn't know about if it weren't for the tinterweb.
21/02/2025 08:50:11 UTC
Ian Soady¹ said :-
Finally got the Electra (1965 Norton 400cc electric start twin for those who've forgotten)> Very slow progress due mainly to various health problems but hopeful for the future.
I'd started it a couple of times and it semmed to be running quite nicely. So I thought I'd hook up the strobe to get the ignition timing correct. Imagine my surprise when I thumbed the button and all that happened was the starter motor spinning. When I looked at the drive, I saw that the sprocket driving the whole caboodle had sheared off its shaft! The sprocket is supposed to be on a taper with a woodruff key. There was no sign of the key and the taper was well mashed up. A previous owner had "solved" this by brazing the securing nut to the sprocket.... Obviously this meant all the turning torque was going through the smaller diameter screw thread rather than the sturdier taper, and this just wasn't up to the job.
Fortunately the main part with the spindle is available from the excellent Norton Owners Club shop. I managed to turn the nut and braze off the sprocket and am in the process of removing the remains of the key from its keyway with a ground-down screwdriver. Sprockets are available from a well-known rip-off Norton spares place at £60 + VAT + carriage so would much prefer to sort it out myself.
This is the general layout:
08/03/2025 16:32:59 UTC
Glyn said :-
My brother has a Fantic 300cc trial bike. When starting it, it backfired due to timing issues. He sent the engine to me because he couldn’t get the flywheel off even though he had just refitted it a few days earlier before the backfire. I’ve tried everything and I can’t get it off either. I assume the key was Ill fitting and the flywheel spun around the crank seemingly welding the two together. I’ve ruined 2 official Fantic flywheel pullers and emptied a gas canister heating it all up but to no avail. I’m now trying to cut the flywheel off by using a hole saw that’s a little larger than the shaft then perhaps I can grind the rest of the flywheel off. There is no alternative that I can see because, without removing the flywheel, I can’t even split the engine cases. So I have complete sympathy with you Ian as I hate woodruff keys as well.
08/03/2025 18:47:58 UTC
Ian Soady¹ said :-
I've often seen described a technique for removing bushes from blind holes involving a well-fitting bar and oil. The drill is to select a round bar that is a close fit in the bush, fill the blind end with oil then a sharp tap on the end of the bar will force the bush out with hydraulic pressure.
I've always had my doubts but being faced with this problem for my Electra's starter assembly I thought I'd try it out. A short length of 3/8" round stainless faced off and slightly chamfered in the lathe, some 40 grade oil and off I went.
To my surprise and delight it worked perfectly! It did need slightly more than a light tap to start it but then the bush popped out very nicely.
Before removal:
09/03/2025 11:33:31 UTC
Ian Soady¹ said :-
In progress:
09/03/2025 11:33:51 UTC
Ren - The Ed¹ said :-
Ian - so the 3 holed 3 sided chunk of metal has the 4th central hole that is "blind" ie closed ended. The bush needs to come out so add oil and closely fitting metal "dowel" and whack it? That's akin to the trick used to remove bearing from the end of a crank behind the clutch - I've seen that done with bread or mushed up paper. Glad it's worked for you, well done.
Woodruff keys - whoever thought a taper and a slot with a feeble lump of metal in it was a good idea?
10/03/2025 17:40:31 UTC
Ian Soady¹ said :-
Yes, that's pretty much it. I needed to get the bush out undamaged as I have a replacement for the main component but it's bare and the bush is unobtainable. I could make a new one but prefer to use what I already have. Bread seems to be an odd choice....
As Glyn has said, tapers can provide a very strong structure and can be a devil to separate. In fact, I understand that all the key does is to align the parts - which is unnecessary in my application. A 1/8" key's not very strong, and in fact if the key's a bit oversize it can prevent the tapers from mating properly. I have a sprocket arriving and will lap it onto the shaft (in the vice jaws in the picture) with fine grinding paste before fitting.
11/03/2025 10:25:26 UTC
Ren - The Ed¹ said :-
Bread to pop out a clutch pilot bearing...
https://www.youtube.com/shorts/Lez-o8jequA...
11/03/2025 19:38:24 UTC
Ian Soady¹ said :-
I also came across the use of play-doh for a needle roller:
https://www.b50.org/phpBB2/viewtopic.php?p=91547&sid=8fe09e68e0367d4cba83d5114b5...
12/03/2025 10:12:49 UTC
Ren - The Ed¹ said :-
Aaaah we can't see that Ian as we'd need to be a member of the forum. Fear not I can see how play-doh would be a suitable medium. I reckon blu-tack, errrr... wax crayon?
Custard? Custard is non Newtonian. So when you whack the bolt/rod it would act as a solid rather than being pushed out the way. Interesting.
13/03/2025 08:14:12 UTC
Ian Soady¹ said :-
The key supplied by the normally reliable Norton Owners' Club spares scheme was incorrect - too big in every dimension. So I thought I'd assemble the sprocket without, after carefully lapping the tapers with fine grinding paste. The result seems to be working well, and I've successfully started the engine with the starter - the object of the exercise - several times as well as whiczzing it over multiple times with ignition off to test.
Of course it will fail when I'm miles from home with no phone signal - but I dod have the kickstart, which works, as backup.
15/03/2025 16:03:31 UTC
nab301 said :-
I've used grease in the past for removing bearings from blind holes with the close fitting shaft/dowel.
As for tapers, Em Zeds have the clutch fitted to a taper on the crankshaft which can be problematic with a decades old bike...
Nigel
15/03/2025 18:32:07 UTC
Ian Soady¹ said :-
I seem to remember people talking about pouring salty water onto tapers so they rusted together. Or maybe not.
16/03/2025 14:00:58 UTC
Ian Soady¹ said :-
With great help from various NOC members I think I'm nearly there with my Electra. The electric starter is now starting it reliably despite the missing key between motor shaft and sprocket. It seems happiest starting from cold with closed air lever and a second or so tickling.
I've finally fitted the primary cover although why the NOC supplied gasket seems designed to go under two of the lower starter assembly legs beats me. I've cut those bits off.
Carburation is reasonable although an even slow idle is hard to come by. At first the mixture screw didn't seem to do much but now is at its best about 1.5 turns out as recommended. There may have been some muck in there that has been blown out. I've checked timing using my remote rotor and as I hoped it's much easier to see that than the alternator rotor. Strobing shows a satisfactory advance from the 10 degree (crankshaft) which seems about right for idle up to 20 degrees or so at 3,000 rpm which is the most I want to inflict on my neighbours at present.
It's very rattly although this is gradually lessening, I assume as oil finds its way where it needs to be. I'm guessing cam followers as I've carefully set and checked the rocker clearances. I have read that these are noisy engines but don't have much to compare it with. There's no smoke from the exhausts and the oil is returning nicely.
I have been wondering about the voltage drop when using the starter - it goes down to about 10.4 volts - so am contemplating fitting a step-up voltage converter like the one in the link to ensure the Boyer gets enough volts.. In fact I've ordered one as it's only a fiver or so. I successfully used a similar device to get indicators to work on the 6 volt system of my ES2. It's probably unnecessary (I have a Mk 4 Boyer) but can't hurt anything. It will be fitted between ignition switched live and the Boyer live as well as the (positive) earth. See link below.
So hopefully will hit the road soon!
https://www.ebay.co.uk/itm/296547776080...
17/03/2025 14:35:18 UTC
Ren - The Ed¹ said :-
You're gonna have to help me here Ian. I totally understand that using the electric starter sucks a LOT of leccy from the system, leaving little for the rest of the bike. This is why modern bikes with computers, FI and fuel pumps WILL NOT start with a battery that is anything other than "on top form" even if it appears to be cranking just fine.
Now a CDI bike doesn't care much - it's spark comes (indirectly) from the pulse coil. How does the Boyer system work? Why does it need "good" power? And that step up DC-DC gadget - the advert advises "(2) fixed output (select) between 12-35 v, when buying, please tell the shopkeeper." Does that mean you say to the shopkeeper "Please can you set this to output 13.5v please"?
18/03/2025 08:09:09 UTC
Ian Soady¹ said :-
Yes, many later bikes like my Yamaha and Suzuki-engined BSA have a self generating ignition system that doesn't depend on battery voltage. In fact, in principle, they're very similar to the old magneto. The Norton feeds its ignition system from the battery - originally using points but I'm using a Boyer CDI system which still uses the battery to power it. The original Boyer system did have problems with low voltage, tending to go onto full advance which is obviously not ideal. The later Mk 4 system I have fitted is said by the manufacturer to be good down to 10 volts. It does seem to be working well but 10.4 volts seems a bit marginal to me especially if the battery has faded a bit. I'm keeping it on trickle charge so all my testing has been done with a fully charged battery.
WRT your second question, no idea - there didn't actually seem to be such an option when I bought the thing. Going by past experience the adjuster is the tiny screw on top of a blue component on the edge of the unit. I'll see when it arrives.
18/03/2025 10:24:46 UTC
nab301 said :-
I've always been a fan of retaining points and coil ignition but I know plenty of Indian Enfield electric start systems have been damaged by kick backs caused by low voltage and those earlier Boyer systems strangely going to full ignition advance..
The step up converter if it works seems like a good insurance policy.
I'm curious how the chain drive starter system operates is there a sprag clutch incorporated in the starter motor?
Nigel
21/03/2025 15:14:10 UTC
Ian Soady¹ said :-
Hi Nigel.
The device arrived and I fitted it but it didn't really do what I wanted. It seems that the output voltage is related to the input so as the latter drops on using the starter so does the output. I could overcome that by using changeover relays but I think I would then be introducing too many potential points of failure so have reconnected as standard and shelved the voltage converter.
The Electra starter is unique as far as I know. It does have a sprag clutch on the crankshaft which is driven by 3 pawls which, when the starter operates, are rotated via slots in a wavy pressure waher acting as a sort of clutch to engage with the sprag. When the engine fires the pawls are retracted as the crankshaft is spinning faster than the starter drive. I hope the attached picture helps. There is no kickback protection which of course is a drawback and may indeed have contributed to the shaft failure in my case. It also needs a well charged battery with decent CCA (cold cranking amps) which I think is a more relevant figure than the amp-hour one which people often quote.
The starter has a pretty poor reputation which I think is often due to wear in the various components. I'm lucky in that mine seems to have seen little use so wear isn't an issue although I did have to replace a couple of items eg the wavy spring.
22/03/2025 10:17:08 UTC
nab301 said :-
Thanks for that Ian , I had done a search but never thought of including the crankshaft when looking for parts diagrams...
Nigel
23/03/2025 10:26:00 UTC
Ian Soady¹ said :-
It's taken from a pdf of the manufacturer's manual, which is a bit light on illustrations. Probably because they didn't actually make that many.
24/03/2025 13:58:05 UTC
Name
Comment
Add a RELEVANT link (not required)
Upload an image (not required) -
Uploading...