I have been pondering the issue of getting a decent tickover whilst the bike warms up. This is a common issue with these old bikes; a feature, not a fault. 🙂
The Amal carbs on my bike are Mark 2 type that have a rather rudimentary cold start enrichment system to provide additional fuel rather than the 'real' choke found on more modern carbs. I turn on the fuel tap, wait for the empty carbs to fill (signified on my bike by the sound of air being drawn through the tank cap breather pinhole), pull the lever that says "Choke" (but isn't), which in turn lifts the cold start plungers. I gently kick her over a couple of times to draw fuel in, switch on the ignition and with the throttle about 1/4 open, give her a proper kick and she fires up first time (mostly).
Great! And it has taken quite a while for me to get her to the point of such easy starting. However, I then have to stand with the bike, patiently holding the throttle part way open whist she warms up. If I let go of the throttle too soon (and I often do), she dies. I am sure it is a familiar story for most of you: if the bike is setup to tickover correctly when warm, she will not idle cold.
The PO's advice to me was to suit up, lid and gloves on, garage locked up and have the bike facing the open road. Then start her up and ride away immediately, in the hope that by the time you have to stop (but not always) she will be warm enough to hold idle.
I am not keen on this plan. Cold engines need to be warmed up and ideally be close to running temperature before being used. Also, I like to start them up and leave them to warm up whilst a get my gear on and lock up the workshop.
So, I have been thinking about potential solutions. As an interim, I have been using one of these:
It kind of works but is not ideal. However, what it is doing is great; holding the throttle part way open whilst the engine warms up, but I think there is a better way....
So, I have a question: what is the thread on the end of the throttle cable, where it screws into the throttle please? If I know this, I think I can relatively easily create a permanently fitted method to pre-tension the throttle cable enough to hold idle until the engine warms up. Once I have tinkered and tested, I will report back.
If anyone already has a solution, please let me know and save me the effort 🙂