Float level ? S1 4.2 does not start

[Durango2k]

Here‘s the U1 photo I promised. Hope it gets through.

These are longer I think, and the tip is different to the UM. I tried to measure the diameter on top and tip, and they differ as well.

[bitsobrits]

That's one scabby looking needle, like maybe a homemade profile? Though wrong needles shouldn't keep you from getting the car to start, if it's so far wrong there is no appreciable clearance with the jet even with the choke engaged then I suppose it's possible the needles could be the issue. In any case, I would start with new, correct, needles.

[Durango2k]

Tried to start it today, and it did not - until I unscrewed the dampers on the domes. Then instant success.

What would be a remedy for this - where to look ? Does it mean „worn pistons“ so „not enough vacuum“ above them ? Or too strong springs, or anything else I should look at ?

I drove it today on the yard. Had to double - clutch first time, and boy did that car go.... my son said instantly after the round he‘s scared of it and its a decent widow maker...

Carsten

[MarkRado]

Get yourself a copy of the SU workshop manual, everything in there.
Are valve timing +clearance, ignition timing, plug gaps spot on? Jet height below bridge 1,6mm (4.2) resp 1,1mm (3.8) as a starting point.

[Gérard A110]

Hi, at first i thought the bees had made their nests in the fuel lines, but i see than no.
For setting, the oil into the damper above the carburator bell must arrive 1 cm before the top. No more.
The 3 jet neddles 1.5mm lower than the top.
It must work, regardless of the spring or bell tighness!.

[Gérard A110]

And for the synchronization balancing betwen the 3 entrances (gates?) if you have not one balancing tool,
use simply one rubber hose ( 1m.) + one funnel .
Apply the funnel at your ear and the hole of hose at the air entry.
You can easy ear the difference of suction, and adjust the big screw for each air.

[Durango2k]

I have the weber tool / for the SM...I‘ll use it.

Currently I have ATF in the carbs, and not SU‘s own oil. And I‘ll check for the 1.5 mm jet height below the bridge.

Carsten

[Gfhug]

Carsten, you can use regular engine oil in the carbs.

Geoff

[Durango2k]

That would be SAE20W50, then ?

Carsten

[Gfhug]

Yes

Geoff