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Momentary Engine Stumble
Posted by: mikeycee ()
Date: March 23, 2020 09:32PM

I have a 110 PG newly outfitted with an OTTO 4 carburetor kit. Engine runs super fine when warmed up. However there can be a stumble on hard acceleration from a stop. If it weren't for that man could I make those tires howl. Also I noticed the garage floor had some black sooty powdery particles under the left exhaust. If is a rich setting how do I correct it or could it be an accelerator pump?? confused smileyconfused smiley Mike

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Re: Momentary Engine Stumble
Posted by: joelsplace ()
Date: March 23, 2020 09:38PM

The soot is not an accelerator pump.
First thing is look down the throats of the carburetors while it is running to see if you have any drips. If you do you have leaky needle valves, high float level, too much fuel pressure or a combination of these things.
The stumble could be accelerator pumps. While you have the air cleaners off you can check for nice streams from the pumps.
Are you running 4 primary carburetors?

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Momentary Engine Stumble
Posted by: mikeycee ()
Date: March 23, 2020 09:57PM

No only two primaries. The secondaries were Wolf rebuilds. I did hear a few isolated back fires yesterday come to think of it.confused smiley Mike

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Re: Momentary Engine Stumble
Posted by: corventure Dave ()
Date: March 24, 2020 09:01AM

Question... At what point do the secondaries open? One could be faster than the other.

Corventure Dave

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Re: Momentary Engine Stumble
Posted by: mikeycee ()
Date: March 24, 2020 09:21AM

The 2nds open around 25%-30% throttle so I'm told by Shade's mechanic. However this happened again in the garage this morning with "crap" all over the floor under the left exhaust duriing idle and choke kick down when warmed up. It ran beautiful after backing it out and pulling back into the garage. I had someone last month tinker momentarily with the idle adjustment screw. Could this be the culprit? Seems like it takes more throttle pumping than normal to get it cold started since then too. However when it's warmed up ii runs great. The ignition bangs right off the minute I hit the key. eye popping smiley Mike

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Re: Momentary Engine Stumble
Posted by: MattNall ()
Date: March 24, 2020 10:07AM

Never "Tinker"!!!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Momentary Engine Stumble
Posted by: solo2r ()
Date: March 24, 2020 11:05AM

What ignition are you running?

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Re: Momentary Engine Stumble
Posted by: mikeycee ()
Date: March 24, 2020 01:12PM

Pertronix #1 and also why is only one exhaust blowing water droplets and carbon and not the other? confused smiley Mike

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Re: Momentary Engine Stumble
Posted by: joelsplace ()
Date: March 24, 2020 01:13PM

This is the first time you mentioned the water. I would guess the other bank isn't running.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Momentary Engine Stumble
Posted by: mikeycee ()
Date: March 24, 2020 04:56PM

You guessed it bone dry. Why would one side not condesate?

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Re: Momentary Engine Stumble
Posted by: joelsplace ()
Date: March 24, 2020 04:58PM

Idle circuit plugged up so it isn't running. Burning gasoline make a lot of water.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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