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Hot start problem

Posted: Tue Jul 24, 2018 3:08 am
by TZepeSH
Hello, I have posted the same question on TOS, I ask it here too:
For a long time now I have had a hot start issue. Engine cold, starts right away. Engine hot, I have to crank it for seconds for a few times, maybe press the pedal a few times (but this can also flood the engine).
Specs: 1584cc, W100, dual Dellorto DRLA36, 28mm venturis, 50 idles, 180 airs, 9164.2 emulsion tubes, 122 mains. Ignition is Megajolt and EDIS, I have tried with 8 degrees cranking advance, now I am at 12 degrees cranking advance with best cold start results. I checked the timing with a timing light, all is spot on as sen on laptop and on pulley marks. After it starts, it runs great, tuned with the classic procedure and wideband.
Fuel pump is electric under tank, so there is no gas evaporation/starvation.
After it cools down it starts again perfectly, so this again would rule out gas boiling/evaporating.
It does turn the same as cold so I would rule out some part expanding and making crank speed slower.
What could be the issue, and how can I solve it?

Re: Hot start problem

Posted: Wed Aug 01, 2018 5:26 am
by TZepeSH
I think that the problem is solved. I was having heat soak issues, so when I turned off the engine the fuel boiled in the carbs and flooded the engine. Keeping the throttle open while cranking makes starting very easy. Maybe I will add phenolic spacers between manifolds and carbs in order to isolate the heat transfer.