Technical Feels like it’s holding back when accelerating at times

[Timowen6]

Hello all.

I have got my 500f back from the garage after some tuning and a bit of tlc to the engine and brakes.
I had the timing sorted as I changed it over to electronic ignition and the original smaller exhaust put on instead of the noisy sports exhaust.
When I set off from a cold start or when running around you can feel almost like a dead spot and it lacks power and feels like it’s holding back.
It’s not happening all the time and can’t pin point to a situation. It’s almost like a fuel problem but it’s a fresh tank of fuel.
It is a new carb, newish fuel pump and a new fuel line.
It is drivable and I could live with it, but it would be good if I could sort it.
Anyone got any clues as to what it could be ?

Thanks in advance.

Tim

 

[Hutbed]

Could require some carb adjustments to compliment the advance curve of the electronic unit, definitely got a bit better once I made carb adjustments after fitting the 123 ignition. Also you can widen the spark gap significantly now, that actually made a noticeable difference which surprised me.

 

[fiat500]

Obviously this is a tricky problem to diagnose as shown by the lack of replies. Assuming all the ignition installation has been done accurately, maybe the HT leads were not replaced? You possibly have a misfire.
On the fuel side, a modern replacement carb would worry me and so worth checking float-level and inspect the main jet for a partial blockage
I've had a similar problem when a split developed on the intake setup before the carb.
Really useful to get feedback on this once sorted. [emoji6]

Hello all.

I have got my 500f back from the garage after some tuning and a bit of tlc to the engine and brakes.
I had the timing sorted as I changed it over to electronic ignition and the original smaller exhaust put on instead of the noisy sports exhaust.
When I set off from a cold start or when running around you can feel almost like a dead spot and it lacks power and feels like it’s holding back.
It’s not happening all the time and can’t pin point to a situation. It’s almost like a fuel problem but it’s a fresh tank of fuel.
It is a new carb, newish fuel pump and a new fuel line.
It is drivable and I could live with it, but it would be good if I could sort it.
Anyone got any clues as to what it could be ?

Thanks in advance.

Tim

 

[Timowen6]

Hi Ian.

It is always tricky as you don’t know if they are being as though as they say. Also if the brake disc conversion is as good as it should be. They came straight from Italy from an unknown suppler.
Think I might have to send it to a mechanic who’s used to working on them.
Thanks again and I will let you know the outcome.
Tim