Author Topic: Idle wells fill with bowl?  (Read 169 times)

Offline fussfeld

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Idle wells fill with bowl?
« on: July 17, 2021, 04:42:07 PM »
Just to make clear:

Let's say we're starting with an empty carb.

And we turn the electric pump on (forget about cranking for now).

Do the idle and main wells fill up as the bowl fills up?  (Assuming the float is set correctly?)

Let's say the engine has not been cranked or run at this point.

Offline 73ss

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Re: Idle wells fill with bowl?
« Reply #1 on: July 17, 2021, 05:34:30 PM »
yes. Do you mean secondary well? that will fill but at a slower rate due to the restrictions.

Offline Cliff Ruggles

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Re: Idle wells fill with bowl?
« Reply #2 on: July 18, 2021, 05:24:34 AM »
The main jets provide a path to the idle tubes and they are driven deep into the main castings so cover up pretty quickly as the bowl fills.

Above the idle tubes either in the airhorn or the main casting just above the DCR's is an upper bleed.  It acts as a vent to prevent syphoning all the fuel out of the bowl after shut-down.

I've seen folks and even companies building carb mix-match main castings and airhorns and come up with combinations where no upper IAB is present.  This doesn't work well and you'd think the bottom plugs were leaking as the carb empties into the intake after shut-down.

Just though I'd throw that out there in case someone has that issues and can't figure out what's going on?.........
« Last Edit: July 19, 2021, 04:50:25 AM by Cliff Ruggles »

Offline fussfeld

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Re: Idle wells fill with bowl?
« Reply #3 on: July 18, 2021, 03:38:04 PM »
yes. Do you mean secondary well? that will fill but at a slower rate due to the restrictions.

i'm mostly concerned about the idle wells at this point;   i'm trying to figure out why i can now get the engine to  start easy when cold (see my other thread in the diagnosis section).

i had tgw carb on and off the engine so many times lately to do adjustments and had to crank alot to get it to start each time i reinstalled it----maybe i was just not waiting long enough for the idle wells to fill up?