HELP! Birmingham Scott won’t start ??

[Deleted User]

I tend to agree with that. Although the gel etc batteries are maintenance-free and don’t spurt acid over your chrome work, in my experience they aren’t great with old-world dynamos and mech regs.
I stick with a little lead-acid battery in a replica T battery case, and a DVR2 electronic reg which I’ve found to be excellent on various bikes now.

[Deleted User]

i had exactly the same faults.i fitted a refurbished carb without checking it and the main jet was missing i wouldnt have minded but i paid £195 for the carb

[Russell]

Many thanks for all the advice, after starting from scratch and checking through everything we’ve finally got in running again 😀

[Russell]

@BRIAN MARSHALL wrote:

Screw the primary air screw fully in (gently !), and then unscrew it 1.5 turns for an initial start up. Fine adjustments can be carried out later.

Not sure exactly what kind of carb we have…
[attachment=0:2u8tmf33]WP_20170730_19_24_04_Pro.jpg[/attachment:2u8tmf33]
But I’m assuming “1” is the throttle stop screw, and “2” is the air screw ?

What’s the best way to set the carb up for optimal running?

Cheers
Russell

[BRIAN MARSHALL]

Yes, number two is the idle mixture screw. Carb is Amal 206/151R.

[Russell]

Okay thanks, any advice on how best to set it up?

[Deleted User]

Dont leave us in suspense Russell what was the problem?

[Russell]

Ha 🙄 hard to tell as we changed so much, but most likely candidate was a poor battery 😀

[Deleted User]

I know this is no help to you Russell (at the moment), but I converted our 1960 Brummie to 12 volts, running 2 6volt coils in series (6 + 6 = 12) and an Accuspark trigger instead of points, no condensor – have you replaced yours Russell ? It started 3 rd kick after standing 3 years, with new fuel of course. If you are getting an abnormally bright spark at the points – could be condensor.
Good luck..

[Russell]

It’s been running great since we got it re-started, starting first or second kick, until I went out on it yesterday. I’d just filled it up with petrol then about 50 yards from the petrol station it faltered lost lower and stopped. I checked round and one of the HT leads had come loose on the spark plug, so tightened it up, presuming that was the problem. Then it wouldn’t start again, so had to call breakdown to get me home. I’ve checked it over today and everything looks okay, but it still wont kick over. I’ve checked that there is a spark by connecting a timing light in series with the plugs, so presumed fuel, but everything looks okay there too, even tried some Easy Start but not a puff or a bang.

So back to square one 😯

There’s just no sign of life, and I know now everything is set okay, totally frustrated 😥

[Russell]

Just a thought, could filling it up with petrol have dislodged some crud in the tank, that’s blocked something in the carb? Is there a way of definitively checking you’re getting fuel through?

[BRIAN MARSHALL]

Diesel in the tank instead of petrol ?! Worth checking…. 🙄

[Russell]

Ha I did check my receipt just in case but no, petrol 🙂

[Deleted User]

Hi Russell,
When setting up the carb, screw the throttle stop right down until the throttle shuts completely. Two strokes should be set up this way to stop popping and jerking on the over run.
Regards,
Bob Mather.

[Deleted User]

There is one more thing worth checking, I found this problem on my ’49 DPY engine.

At some time in its life it seems someone tried to ‘improve’ the ports on this engine. As a result they broke through the crankcase casting from the inside edge of the bottom LH transfer port to the flywheel space. They then filled it (badly) with plastic padding or something like it. Time, oil & vibration took their toll and loosened up the plug allowing air to bleed in.

I found myself a top-notch welder who filled up the hole for me. After a brief visit to my milling machine for a refinish of the transfer port gasket face all was well.

The point here is that, at least in the case of my engine, the casting is pretty thin so not only is there a danger of over enthuastic port polishing but I have heard that casting porosity is not unknown.

It would therefore be worth the time spent to do a very critical inspection of all the intake tracts and mating faces.

[Author]

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