classic motorcycle forum

Despite Amal's tuning instructions I always leave the main jet till last. I start by fitting one which is oversize - say 250 if a 220 is specified - then get all the other bits right as the vast majority of running is done in the cutaway / needle jet area. Good idling is also very important to me. It's a point of pride to get a steady idle and clean progression although sometimes it takes a lot of effort to achieve those.

The main jet only comes into effect at wide open throttle (unless it's too small of course). And apart from racers (and feeble 2 strokes), who uses that for any length of time these days?

A tip I had from Tony Cooper of mag and dynamo fame is to drop a 3/8" bolt between the clutch lever and abutment so lifting the plates slightly. This helps to avoid them getting stuck in the first place.

Do remember to remove it before trying to start the bike however......

Also make sure the rear sprocket is in line with the chain (as best you can). This will at least tell you if the wheel is correctly located in the frame.

I find it harder to do this than line the wheels up as chainguards and bits of frame get in the way......

Although I didn't have it for long, my Arrow started perfectly happily when hot with its original Monobloc. Poor hot starting is often caused by heat soak into the carb. Do you have the proper insulator between carb and crankcase?

Have you tried the AOC forum for information?

Green is always connected to the field ("F" terminal) on the dynamo, yellow to the "D" terminal.

Those wire colours in the loom sound totally wrong to me. Essentially you need to take the live feed from the regulator to one side of the ammeter (and the feed for the lights etc are also connected here) and the battery live to the other. However, feed to the horn and stoplight switch are normally taken from the battery side so as not to give confusing ammeter readings.

You need to make sure the polarity of the dynamo corresponds to that of the battery. ISTR you're dealing with a 50s BSA in which case it's likely to be positive earth although swapping over isn't an issue.

I would buy some wire of the correct colours and rewire it. An easy afternoon's work. Trying to deal with previously bodged wiring is a nightmare.

Here's an example diagram:

Always worth giving Allan Hitchcock a try.

I agree. There should be no reason for GDPR to cause any forum to cease operation.

As for FB - I do have an account (with completely fake details and all "privacy" enabled) but find the "forums" pretty inane. The occasional useful postings are drowned out by the dross. But then that's the case for some non-FB ones as well - I'm sure you know which ones I mean.

I would check with the engine running as that will give you a good idea of the charging voltage. However, Emilios' readings are strange. Perhaps due to a voltage regulator hunting?