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
Ian Soady¹ said :-
I thought you folk might appreciate this. Modern carburation / injection systems generally have some sort of mechanism to slightly raise the tickover speed when the engine is cold. Simple slide carbs like the Amal fitted to my Norton don't, so you either set tickover to be correct when it's hot which means it tends to die until it's warmed up, or correct when cold in which case it races when it's hot.
Some pre- and just post-war Nortons and Velos had what they called an easy start device. This was very simple and was merely an extended throttle stop screw with a stop which abutted the carb body. You rotated it clockwise, hence lifting the slide, to increase idle speed when cold then back to the stop when warm, obviously setting the stop accordingly.
So I thought why not make something similar for the fake Amal on the little Norton. It was simple to find a spare throttle stop screw in the Amal pile, bore the outer end 3mm diameter then make a stepped component out of a bit of scrap phosphor bronze. A Schrader / Presto cycle valve adaptor provided a nice knurled knob for the outer end. A pointer was made from 1.2mm alloy and secured to the adaptor with a valve securing nut. All was then soft soldered together. I have to eport that it works very well although for various reasons haven't taken the bike on the road with it yet. The picture shows the Mk 1.0 version - version 1.1 has the pointer / stop made out of thicker material to be more robust. If I were to bother with V1.2 I'd make the whole lot a bit longer as it's almost colliding with the float chamber edge.
02/10/2025 16:51:03 UTC
Upt'North ¹ said :-
Ian, looks a job well done.
But.....there's always a but.....why didn't British carburetor manufacturers think it might be a good idea to fit a choke for our inclement climate.
Do we just like a tickle?
Upt.
03/10/2025 10:53:56 UTC
Ren - The Ed¹ said :-
Help me out here Ian. Am I correct in thinking what you've created is a throttle stop screw with a pointer? The idea being with experience you learn to start the bike put the pointer to position X then when it's warmed up turn it to position Y. Position X And Y are learned from experience. If it works - it works!
Now - a man with a lathe and your skills should be able to engineer some kind of automation for this surely. I'm thinking bimetallic strip attached to the engine such that as the engine warms the bimetallic strip curls or uncurls, automatically adjusting the throttle stop. At the absolute minimum a remote operation lever...
03/10/2025 14:41:53 UTC
Ian Soady¹ said :-
Possibly I haven't made myself quite clear. Not for the first time. There is an enrichment device which is a simple air slide which runs inside the main throttle slide. This does confuse many people as it operates when the handlebar lever is closed. This gives the rivh mixture - assisted on some bikes (not the Electra) by, as Upt' suggests, a tickle. It is crude however as once it os slightly opened it only works at larger throttle openings and does nothing at idle.
But when the engine is cold the rich mixture on its own is not enough to run the engine fast enough to stop it dying. Hence my device. Essentially it allows me to set the idle speed when the engine is hot, with the pointer / stop touching the carb body to the left and the screw at its most extended position hence the throttle slide at its lowest. The whole arrangement is rotated clockwise thus slightly raising the slide for a cold start - the exact amount to be determined by experience / ambient temperature. The device does work as hoped but haven't yet road tested it.
And why would I want to complicate it with electronics or even a cable control? It's only used once per run after all. I once had an Austin Maestro that had a bimetallic choke and it was a nightmare. Hot or cold was fine but warm you had to get out and jiggle the SU's damper rod to get it to go. Actually, SUs also had a little cam arrangement which when the choke was pulled out - which lowered the jet - a little cam also opened the throttle butterfly a small amount. Like my device essentially.
03/10/2025 15:19:01 UTC
Glyn said :-
Nice innovative design that Ian. Strangely, I have a similar issue on the Intruder. That is; perfect tick over when hot but it’s only too happy to die when cold. My issues will be different to your though as I have twin carbs which are probably out of sync causing the problem. I’ve bought new rear shocks as the old ones don’t seem to have any damping and the bike jumps up and down on the springs. However, most of my time is being spent repairing a friend’s fairing off his TZR. I must be mad it’s so time consuming!!
04/10/2025 20:44:01 UTC
Ian Soady¹ said :-
Thanks Glyn, not that innovative as based on a pre-war Amal item! I assume your carbs are CV type - usually they have a separate cold start mini carb arrangement that both enriches the mixture and raises the idle speed a bit. I agree my solution would be a bit fiddly for you....
05/10/2025 10:30:18 UTC
Ren - The Ed¹ said :-
It is then "set" in the warm idle position when the pointer touches the carb body - giving you a solid reference point. For the cold start you will rotate it as you see fit depending upon the temperature etc.
I was rather teasing you about automating it Ian. I too recall the "auto choke" systems on cars of the past. Various bimetallic strips, levers, coolant pipes, and fudges that never would work. It has been my experience if you have 2 engines of the same make, model, year, and mileage one will need choke even if it was just run 10 minutes ago whereas the other will never need choke even in the depths of an artic winter.
Lord only knows how the electronic FI systems cope with this variability.
06/10/2025 08:06:56 UTC
Ian Soady¹ said :-
Yes that's right Ren. I'll be testing it in real life later today hopefully. As far as EFI systems are concerned, they use the idle air control valve to maintain idle speed. As its name implies, this allows more or less air into the engine at idle speed by monitoring the actual RPM and opening or closing accordingly. The electronics then regulate the amount of fuel supplied - and of course ignition advance - by monitoring ambient temperature etc etc. But of course you know this. I think you're like the helpful detective sidekick (Dr Watson, Lewis etc) who asks questions they know the answer to so that the audience is given insight into various arcane subjects.
06/10/2025 09:54:28 UTC
Ren - The Ed¹ said :-
Did you get to test it Ian?
07/10/2025 09:29:03 UTC
Ian Soady¹ said :-
Yes, short 35 mile run yesterday morning and it worked very well. Started with the device rotated about 90 degrees then backed off after a few miles giveing a good idle but I still have to sort out the slow running mixture. I'm very pleased so far. The bike is performing well and another run without calling on the helpful chaps from Britannia!
07/10/2025 10:00:11 UTC
Ian Soady¹ said :-
The eagle Steib has landed! Now in my shed and looking great. It will be a while before I get around to it as I have the little BSA C11 to finish - it's nearly there - and still struggling a bit with the Electra although that is so much better than it was.
The Steib is mostly there and is in very sound condition. I plan to have the body (or boat as it's known) painted by a local sprayshop to match the B'Zuki tank, and will paint the chassis black with coach enamel. I can see me producing huge piles of swarf as I make the mountings......
24/10/2025 16:29:11 UTC
Glyn said :-
I’m looking forward to this Ian, a great project for you ( and us). I’ve taken a fancy to a Honda CX500 that is localish to me. Got to get the money right first. Everyone I know is warning me off saying they’re like riding a jelly and an awful bike. That just increases my interest. In the past few weeks I’ve been restoring a friends TZR fairing. It’s been a long winded task.
24/10/2025 17:57:25 UTC
Ian Soady¹ said :-
Those look lovely Glyn, perhaps I should commission you to paint my sidecar! Do you have "proper" [ainting equipment or is it done with aerosols? I've had decent results with the latter although the metallic finish on my XBR tank was a bit fraught as it needed 11 coats each applied within 10 minutes of the preceding one. But it turned out well enough I think.
25/10/2025 10:06:04 UTC
Glyn said :-
That paint looks great Ian. The real finish is obtained after the paint has been applied. Rolls Royce used to hand brush paint their cars and then the real work began. My local paint supplier says that many top bike restorers use rattle cans to great effect. It’s not possible to paint a car with rattle cans because of the large areas and large amounts of cans needed. I have a decent spray gun with a large compressor but I hardly ever use it. It’s such a faff to set up. I painted these panels with Rainbow aerosol cans specially mixed after being scanned on a spectrograph. The total invoice for the cans came to £159 so it’s not a cheap thing to do. After the 3-4 base coats are on, I knock it back with 1000 wet and dry until all blemishes are gone and ( if there’s enough paint still on the panel) apply 3-4 coats of Premium lacquer. Then after 3 days, take that down with 2000 wet and dry before polishing it up with T cut or similar. There was about 5 days work on those panels and I haven’t started the side cowls or tank yet.
26/10/2025 08:37:11 UTC
Ian Soady¹ said :-
Thanks Glyn, I think I spent about £50 on the tank and side panels. I got a local paint factor to scan one of the original side panels and fill aerosols for me - they used a silver base coat. The metalflake effect doesn't come out well in the photos but was quite evident in real life.
I'm happy using brushed coach paint - I use Paragon which inmy experience is better than Tekaloid - for most things but an area as big as the sidecar would stretch my abilities too much hence using a professional body shop. I've been quoted £550 which although sounds expensive is probably reasonable. I remember paying about £350 a few years ago for a Guzzi V50 tank and side panels.
26/10/2025 10:02:26 UTC
Upt'North ¹ said :-
I think most of the paint shop costs are down to the prep time. Do it ya'self and save a few quid. Deliver it in primer and let them finish it off.
Have you thought about sandblast and powder coat Ian or wouldn't it be suitable for this.
Upt.
26/10/2025 10:18:36 UTC
Ian Soady¹ said :-
You're right about where most of the costs are but it's a big thing and my energy isn't unlimited. Blasting / powder coating did cross my mind but (a) I'm looking for a pretty exact colour match and (b) the finish wouldn't be as good as a proper spray job. It would be cheaper though. The main problem is that when done it'll make the rest of the bike look very scruffy.
26/10/2025 14:23:25 UTC
Ren - The Ed¹ said :-
In my world the only purpose of paint is to prevent (further) rust.
I admire Glyn's efforts with the TZR panels and Ian's work on the XBR, but I would have neither the skills nor the patience to properly carry out the preparation and painting. I figure if I were truly "into" the aesthetic then I would find the patience, take time to learn, and put in the effort.
29/10/2025 08:12:22 UTC
Ian Soady¹ said :-
Yes, we've seen your bikes Ren. This is why you keep having to buy new ones....
Refinishing the XBR tank and side panels did take a huge amount of time and effort which is one reason I'm farming out the Steib body. A proper paint shop has good professional machinery for flatting etc rather than the copious amounts of wet & dry or production paper I use. And I've never had the courage to attack what to me is the final finish with more wet & dry as I envisage it all ending in tears and having to do the lot again. Still that's some lowlife's problem now.
Just been checking what I've got and I have a surplus of the alloy trim strips which need a good polish. How on earth I'll get to the fastenings up near the nose beats me - I may have to enlist the help of the young woman who helps Electra with the gardening as she's pretty flexible. I've ordered a tyre & tube from demon tweeks.
29/10/2025 12:16:18 UTC
Ren - The Ed¹ said :-
Wait a minute...hang on....!!!!!
"This is why you keep having to buy new ones...."
Right. OK. So. The current "68" plate CB500X was purchased in 2019 which means I've owned it for 6 years and put 60,000 miles on it (including 2 quiet years due to Covid). Before that I owned the '16 plate CB500X for 3 years and put 39,000 miles on it (traded in against the 68 plate). I also owned the CBF125 for 10 years and put 100,000 miles on it.
It's hardly like I'm having to swap bikes annually. It's not like each bike doesn't hardly get used. Oooooh the cheek and impudence of some folks!!!
29/10/2025 13:20:11 UTC
Name
Comment
Add a RELEVANT link (not required)
Upload an image (not required) -
Uploading...