G starts coughing under load

Big Jugs · Jun 9, 2013

G starts coughing under load. doesn't start this til the load gets greater(in tractor pulling) Have a good mag(tried 2, same result) carb seems fine. going to try different carb. checking valve lash....any other suggestions? Thanks.

Anonymous-0 · Jun 9, 2013

Coughing or missing? Missing under load is usually plugs.

Earl-IL · Jun 9, 2013

Does it start missing at 100-150 feet, fuel cap not vented, main shutoff is restricted,(valve worn & holes miss aligned, float level, too small needle & seat ,usually the rubber tipped ones. Good place to start.

Christopher S. · Jun 9, 2013

I will second the sparkplugs. Auto lite 3116

BushogPapa · Jun 9, 2013

As Load increases, Voltage required to FIRE the plugs must increase because of the increase in cylinder pressure as Load increases..
Still could be Ignition...Plug Wires failing or carbon tracks in the Mag...

JDBPuller (Ray) uses a Pyrometer to keep track of exhaust temps..(Mixtures, etc)..

He also had a remote way to adjust the mixtures as he pulled..(Carb-O-Matic)..

Ron..

gtx1967jewison@yahoo.com · Jun 9, 2013

If the compression is much at all above stock a regular mag wont cut it. You need a super HOT one at that cylinder pressure. Good plugs too. Lack of fuel is the other possibility.

Ben.So.Tex. · Jun 10, 2013

Mine started doing that at the last tractor pull.
Dirty screen in the fuel bolt, cleaned it run fine now.

Mike M · Jun 10, 2013

Could be as simple as the load screw not out far enough ? Do you have the "big nut" carb. on it ?
They have an extra hole drilled in the side of the stem to let even more fuel in then the needle size will allow. Make sure that hole is open !

G's like lots of fuel.

G starts coughing under load

Big Jugs

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Earl-IL

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Christopher S.

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BushogPapa

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Ben.So.Tex.

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Mike M

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