Carb Fuel Evaporation?

[AJ/FormS]

I have verified that there is fuel before cranking and even after 2 weeks there is still fuel in the bowel enough to give 5 to 6 good squirts.

My typical cranking time is 3 to 4 seconds at a time. I would not crank it for a continuous 30 seconds.

Modern gasolines are made up of IDK at least a dozen different fuels. In the old days when everything was carburated, and had vented tanks, some of those fuels were volatile and easy to light, for quick starts. They were called VOCs. But with the advent of EFI, a high percentage of those VOCs were not needed, and so they were removed. Yes, they evaporate right out of your carburator, leaving the heavier molecules in the bowls. but guess what, the exact same thing is happening in the tank....... so after a week those VOCs are gone and you are still trying to start your car on the left-over syrup, even if you install a pump back there.
Honestly, IMO, there are only a few cures for this;
1) Do what I do, I keep a 500ml pop-bottle under the hood, filled with gas and, mixed with 3% 2-stroke oil in it, and a tiny amount of stabilizer. On Friday night, I splash a a couple of teaspoonfuls down the airhorn (no choke), hold the gas pedal down about half way, and crank until it lights off; Badaboom! That pop-bottle lasts all season...... because it is sealed and out of the sun.
2) the cheapest cure is to install some fuel stabilizer in your fuel, and seal the tank when parked.
3) get a double-pumper carb, you know you want one anyway, right? lol
4) get you some alloy heads and reset the cylinder pressure to around 185psi. The heat of compression will evaporate the lightest molecules of the remaining fuel, and away you go.
If you have a low compression engine with a big cam in it, you kindof shot yourself in the foot.

As for cranking;
If it doesn't light off with 3 or 4shots, on the first try; think about it. If you keep doing it, you are washing the oil off your cylinder walls and your compression is going away, and to top it off, some of that gas is going past the rings and into your oilpan.
The factory monster starter will crank your lo-compression engine, IDK, till the battery dies at least, it is a brute; just crank it! I have a Dakota mini-starter on my 11/1, 367, and it takes a lot of abuse as well.
What I mean to say is 4 or 5 second bursts are nothing to it, even 15 second cranks are not much stress.
IMO, you are being overly cautious with your crank-time
#1 above costs you nothing but maybe 2 minutes of your time and is guaranteed to work .

Happy HotRodding

BTW: Carter makes a draw-thru electric pump that you can install at the back and shut off after the carb is primed.

 

[Bewy]

AJ,
In the above post you say, 'Do what I do'.
If I did that I would have a very sore typing finger, lol....

 

[Kendog 170]

The factory monster starter will crank your lo-compression engine, IDK, till the battery dies at least

Post#10 That's why I start mine like this. I don't need to kill my Battery Cars been sitting and Battery has too. Maybe I'll post a video .It's been over a month since I started my Ragtop. My hardtop is inaccessible right now. lol I miss my garage.