Technical 1970 Fiat500F Power Loss under load

[MotoLojo]

Greetings all! My 1970 Fiat 500F after successive carb replacement, cleanings and filter replacement starts up fine, and after idle speed adjustment runs fine as well. However, after I get it warmed up, on the road and out of first gear, the engine seems to lose power. It seems intermittent as it will suddenly gain power back, but I have to keep the idle speed high in order for it to get back to first gear, then of course...back to the garage. I pulled the plugs and they are blacked indicating a possible rich fuel mixture, but I'm not sure. They are not brown or oily. It has an electronic distributor (123) and it is set perfectly. Any help or suggestions would be most helpful. Thanks in advance!

 

[the hobbler]

Greetings all! My 1970 Fiat 500F after successive carb replacement, cleanings and filter replacement starts up fine, and after idle speed adjustment runs fine as well. However, after I get it warmed up, on the road and out of first gear, the engine seems to lose power. It seems intermittent as it will suddenly gain power back, but I have to keep the idle speed high in order for it to get back to first gear, then of course...back to the garage. I pulled the plugs and they are blacked indicating a possible rich fuel mixture, but I'm not sure. They are not brown or oily. It has an electronic distributor (123) and it is set perfectly. Any help or suggestions would be most helpful. Thanks in advance!

If you still have all the original 'points' ignition parts, I would be tempted to refit them and see what happens. The "123" ignition system suffers the same way as ALL of the electronic ignitions do---they hate heat! The 'cooling-air'coming from the engine and out through the Thermostat housing blows this (at times very) hot air straight over the distributor. In fact I believe that it says on the side of the "123" distributor that 100C is "wilt " point. I am also advised that the "123" system is no longer made in "The Netherlands" and as a result, the quality is not as good. as the original.