914 and 550, both T4, One Cold Starts, the Other Doesn't, Why? Options

[Tastyplacement]

This is baffling to me. I have two type 4 cars, both have 914 motors and have a lot off commonality to them. My 914 starts cold no problem. My 550 replica is a total hassle to start cold.

The 914 which cold starts very easily:
-1.8 liter motor
-twin IDF 40 with no choke and no cold start circuit
Main Jets are 115
Idle Jets are 55
carbs were recently completely rebuilt
-Pertronix Ingnitor 1 points replacement

The 550 replica:
-2.3 liter motor
Main jets are 155
Idle jets are 65
carbs seem great, but haven't been thoroughly cleaned recently
-twin IDF 44 with no choke and no cold start circuit
-Pertronix Ignitor 3 points replacement

The 914, I pump the pedal once, car starts every time and is immediately steady. The 550, I have to pump the pedal 4 or 5 times and It'll fire quickly and die quickly. Once I do this a few times it'll run if I keep it at about 2000rpm by feathering throttle. Once it is warm, it's awesome.

[porschetub]

Wow huge jets...why,those mains are massive, what vents are you running ,if that makes it go your vents are too big.
Bigger is not better,camshafts are the same (IMG:style_emoticons/default/sad.gif)

[ChrisFoley]

Wow huge jets...why,those mains are massive, what vents are you running ,if that makes it go your vents are too big.

Those aren't too large for a 2.3L with a long duration camshaft.
It might even call for bigger mains and bigger airs.
I wouldn't hesitate to put 36mm venturis in those 44s if the engine is configured for top end performance.