I agree - plus modern (Oz) unleaded fuels are quite different from the old leaded fuels these engines were designed around. Modern cars make more adjustments with their electronics to ignition timing etc than is possible with 1970's tech. Also they evaporate some components (aromatics) faster.The actual problem is fuel evaporation within the float chamber. A 123 ignition system actually only replaces the points and gives a very small advantage in spark intensity due to a consistent rise time (dwell) for the coil and consistent time the engine gets its spark. A better coil gives a better spark during this cranking time as the starter motor robs quite a bit of current-remember the engine is also a lot harder to actually turn over when the engine is cold.
There is actually little you can do to the carbs to overcome this apart from checking them over and making sure everything is correct-things like the needle and seats in the float chambers, replacement of the float chamber gaskets and the idle mixture settings, accel pump jet settings etc are as they should be but greatest improvement is to ensure the starter motor is not robbing too much power ( a relay in the starter circuit is highly recommended both for switch protection and to ensure proper current). It would also pay to check the starter solenoid points and the brushes.
You should also give those three pumps BEFORE you turn the engine over not as you turn the key.
Designed to run on unleaded, in that they have hardened valve seats. Lead is an upper cylinder lubricant as well as knock inhibitor.<snip>ducantibruce I thought these cars were designed to run on unleaded though. Still I do acknowledge that there are probably other ways that modern fuels differ. I am wondering if using something like BP Ultimate 98 octane would make a difference?
Have a look at the things that I have done that have NOT cured my starting problem. I went to the expense of having the carbs professionally re-built and the jetting checked, rolling road tuned etc. If you are doing as much cranking as I am then I am not convinced by it being caused by the difference in modern fuel. 2 or 3 minutes cranking is an awful lot of fuel just to fill the float chamber and suggests the fuel line is going dry too. Most people's Bertones start reasonably it is just a small minority that don't - surely if it was a fuel problem then the problem would be more widespread? There are some other threads about this problem too (on other forums as well - Alfaowner I think). I am not convince by the starter cranking either as I get a much higher cranking speed in the summer but no difference in the starting - I get a huge healthy spark as well so I am sure it is fuel.Yes my thoughts have been centered on the carby. It does need an overhaul for sure.
ducantibruce I thought these cars were designed to run on unleaded though. Still I do acknowledge that there are probably other ways that modern fuels differ. I am wondering if using something like BP Ultimate 98 octane would make a difference?