I originally thought the Dell'Orto FZD was boiling out if I shut the car off hot and then try to re-start shortly after. I put in a thicker spacer to help keep heat transfer down. No luck. I just installed a low pressure electric fuel pump to augment the 650 'sport' engine's stock pump and I see no difference. If I let it pump fuel for a few seconds or not. It still hates starting when hot. So, maybe the fairly new Bosch blue coil is getting too hot? Seems they're all hot when used (12vdc at the coil / no external resistor.) I'm getting nowhere this way. The stock dizzy is awful flimsy but the car runs great. Is it worth changing to the 123 ignition? And how does the dual coil thing work, anyway?! I would change both at once, but how do you connect two coil wires? Pics of a setup would be nice to have. And has anyone cured hot starting issues on a slightly hot-rodded 650?
Technical 123 Ignition Question and advice on hot start issues
- Thread starter marcus550
- Start date
Currently reading:
Technical 123 Ignition Question and advice on hot start issues
deckwood
Member
- Joined
- Jul 17, 2011
- Messages
- 25
- Points
- 81
Not sure regarding the hot starting, but I run a twin coil with resistor with a zelmot distributor which is converted with electronic points setup, from Hotspark online. lots cheaper than a 123 ignition
So the plug leads go directly from the coil? I don't understand how the entire system connects. I see a complete 123 ignition with what looks like a stock distributor (#1, #2 and coil on the cap.) How does this work with a dual coil? Or is the 123 different for dual-coil use?
deckwood
Member
- Joined
- Jul 17, 2011
- Messages
- 25
- Points
- 81
There are a few different 123 ignitions. I think the one you are looking at, has a standard looking distributor cap, this one uses the standard coil.
The other type of 123 ignitions have a flat top and use a twin coil.
I am using a twin coil (wasted spark) and a electronic conversion kit (no points) such as this; with my original distributor;
Electronic Ignition Conversion Kits for 2-Cylinder Magneti Marelli (Zelmot) Fiat 500 Moto-Guzzi Distributors
Electronic ignition conversion upgrade kits to replace contact breaker points in 2-cylinder Marelli non-vacuum-advance distributors, Fiat 500, Loop-Frame Moto-Guzzi Motorcycle V700, Ambassador, Eldorado
www.hot-spark.com
For my system it is connected as per the above picture however it isnt shown but there is another 12v+ from the +ve side of the twin coil going to the distributor and a return wire going to the -ve side of the twin coil. It works well, no points, no condensor, no rotor
I think my electronic kit was around $80 Australian from ebay and have had no issue with it.
If you have an alternator, you MUST use a ballast resistor, otherwise you will fry your coil.
You can also just buy an electronic conversion kit and use the standard coil, and leave in the rotor cap.
I wouldn't buy the 123 to cure difficult starting, hot or cold I wouldn't buy it in any case....poorly designed and zero aftersales support.
If you do buy it, it comes with very clear instructions regarding the wires. It needs a standard 12v coil, ideally something like the Bosch blue. Use a Bosch blue coil with standard points, in good condition and adjustment and the engine will start just as well as any electronic ignition. Get the timing wrong with any type of ignition and overheating is one of the likely outcomes.
the hobbler
Distinguished member
- Joined
- Jul 25, 2012
- Messages
- 4,502
- Points
- 1,133
The main ignition problem with the 500 (and 126) engines is---HEAT. Unlike practically all other engines, the 110 and 126 engines have hot 'cooling' air blowing over the distributor---neither electronic ignition units (of ALL types) or modern-made condensers like being subjected to over 100C for very long. I agree with Peter, in many ways the system that will give the least ignition problems is a well set-up 'points' ignition with a good coil (Bosch 'Blue' is a good choice, but they are in VERY short supply at the moment) with a 'SWIFTUNE' condenser, fitted up by the coil, and therefore away from the heat. The 'Swiftune Competition Condenser' has both the 'feed' and the 'earth' leads long enough that it can be fitted remote from the distributor. It is a very high quality part, designed and made for classic race cars where the class regulations rule that the ORIGINAL ignition system has to be used---even GT40s have to use the original style 'points' ignition.
On my own car, with a 'well enhanced' 126 engine fitted, the 'wasted-spark' twin-outlet coil is fitted on the left-side of the fan housing with very short ignition leads to the plugs. The distributor has a 'Hall effect' electronic ignition fitted, with no rotor arm and just a cover (ie not a distributor cap). I have built a small 'air-dam' into the thermostat housing which does reduce the heat flow over the distributor---by about 10C, enough to keep it under 100C. If you would like to contact me direct ([email protected]) I will take some photos of my system for you and advise you of the coil that I fitted.
When I mentioned that I had a 123 ignition to a Fiat mechanic here in the States he said not to put it in because of heat. Sorry, I have no other details. I subsequently decided to have a new 700 engine built so I never followed up and still have the 123.
To pile on what @the hobbler said, don't bother with the 123. Several of us here have had them and they've let us down over time. I'm back on points with a Bosch Blue coil and Swiftune condenser.
