71T engine flooding when hot

[smiles11]

Looking for some thoughts on this. My 71T is flooding super fast when hot. So much so that it shot out raw fuel from the exhaust once I finally got it to turn over. Even then, the car dies instantly when trying to let it idle. I thought maybe it was just from it being too hot out, but I’ve never had this experience before. Even 10 months ago, I had the valves adjusted, carbs adjusted & compression/leakdown tests were great. I had those done as the engine was rebuilt & I wanted to get everything adjusted after around 5k miles on the engine. What would cause this issue? I’m going to try it early in the morning when it’s cooler & the fuel has evaporated. Hopefully it was just some bad fuel.

[smiles11]

Turns out it was bad fuel. Added fresh fuel & gallon of 110. Car driving good again.

[PeteKz]

sounds to me more like a float valve leaking or stuck open. Maybe the piece of crud dissolved with new fuel or worked its way loose. Keep an eye on it.

[smiles11]

I was thinking a stuck needle valve at first. Taking it out for a long drive today. Will keep an eye on it.

[wolffie911]

This may or may not be causing your problem but make sure you have phenolic spacers between the cylinder heads and intake manifolds. When you shut the engine off after a spirited drive, the engine heat will migrate up into the carbs and heat the fuel in the float bowls and cause fuel to spill out and if the engine is restarted before the fuel evaporates, a backfire will light it up with unpleasant results. A lot of us oldtimers learned this the hard way back in the day. Oh, you do carry a fire extinguisher with you, right?

[smiles11]

That could be it. I did have a spirited drive yesterday up into the foothills. The fuel blasting out the exhaust pipe was concerning. I knew the engine flooded, but it hasn’t happened in so long since the valve adjustment/carb tuning.

I took the car out this morning & it was business as usual. The car is properly dialed in. So the heat expansion into the carbs could have been the issue. It’s also been the first real weekend of higher temps here in Northern CA.

Once the engine had cooled, added fresh fuel + gallon of 110, stabil, & Techron fuel system cleaner for good measure. Everything cleared & back to normal.