hard start when warm then gas smell

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hi, i did search several key words to see if this was covered - some close but ultimately not helpful. here is my situation: i have a standard '69 02, 2 yr old Weber 32/36 with CDs prescription on jetting, car is tuned well with all decent wires, plugs, new pts, timed right. car runs like a champ. recently been intermittently hard to start when warm, cranks and cranks, then slowly catches, then gas smell, then runs fine, never any gas smell otherwise and starts fine most of time on the 'button'.

i've done a visual inspection, don't see any gas leaks, looked when running, no leaks.

any suggestions?

thanks, Chuck

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ignition points are fine in my book -

BUT DWELL meter is the best way to adjust the gap-

ton's more accurate (and motor runs better!)

than using a 0.015" feeler gauge method

idle speed mixture make a differance also

...and valve adjustment (if too tight - that will cause some gas smell ?)

and also unburned gas during long cranking will cause added stink

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hi creighton, thanks for input, i do use a Dwell Meter for sure. i had checked the valves about 6 mo ago, but will do again. i also had what i thought was a lean condition this winter, so i did make idle mixture richer...i'll look at that.

thanks, chuck

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in the carb--if the float has gas in it and/or the needle valve doesn't seal properly, fuel will be forced past the needle valve when the hot engine is at reast (gas expands when hot), causing the excess fuel to overflow the float chamber and run down the carb throat. This'll cause hard starting and a gas smell.

I've had floats (plastic and brass) sink with all hands on board at least three times on three different cars/carb makes over the years. When the float sinks you won't be able to start or run the engine due to flooding, but one that rides low will still allow eventual starting.


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Could be hot flooding-

Jenn's car does this,

and can be hard to fix. Especially if you use an electric

pump that holds pressure when it's off.

What happens is that the float valve is either slightly leaky

OR fuel pressure builds too high in the system. When you shut down,

the float bowl overfills, and floods the carb- the easiest

way to diagnose this is if a WOT hot start works a lot better

than just trying to start it normally.



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