Allis B and wc problems

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   I have a 39 B and a 37 WC and bolth run and start great but once they get up to temp they start running funky and start wanting choke to run, they do it bolth under load and just idling but after about 5 minutes they will start running great without choke again, the B will try and die but at soon as you give it choke it kicks right back up and the WC will keep itself running but you can tell that its just the governor flipping it open and closed to keep it alive. Does anyone have any ideas? Bolth carbs have been rebuilt, the B has a new manifold gasket, professionally rebuilt mag and the head has been decked. Would maybe running lead substitute in the fuel help? Thanks.

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Ttague39B Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 09 Aug 2025 Location: Tunkhannock PA Points: 62	Post Options Post Reply Quote Ttague39B Report Post Thanks(0) Quote Reply Topic: Allis B and wc problems Posted: 14 Jun 2026 at 5:58pm
	I have a 39 B and a 37 WC and bolth run and start great but once they get up to temp they start running funky and start wanting choke to run, they do it bolth under load and just idling but after about 5 minutes they will start running great without choke again, the B will try and die but at soon as you give it choke it kicks right back up and the WC will keep itself running but you can tell that its just the governor flipping it open and closed to keep it alive. Does anyone have any ideas? Bolth carbs have been rebuilt, the B has a new manifold gasket, professionally rebuilt mag and the head has been decked. Would maybe running lead substitute in the fuel help? Thanks.

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Hubert (Ga)engine7 Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Jackson Cnty,GA Points: 6677	Post Options Post Reply Quote Hubert (Ga)engine7 Report Post Thanks(0) Quote Reply Posted: 14 Jun 2026 at 6:41pm
	Having to use the choke points to a fuel flow issue, maybe insufficient flow from the tank or float level adjustment problem. With the problem occurring after it warms up it could possibly be a condenser or coil breaking down but it is unlikely that you would have the same problem with both tractors. Do you have the fuel lines too close to the manifold? Valve adjustment is another thing to consider especially if both have been recently rebuilt. Try using mid grade gas and see if that helps any.
	Just an old country boy saved by the grace of God.

daveingreenbay Members Profile Send Private Message Find Members Posts Add to Buddy List Silver Level Joined: 09 Oct 2009 Location: Green Bay Points: 303	Post Options Post Reply Quote daveingreenbay Report Post Thanks(0) Quote Reply Posted: 14 Jun 2026 at 9:15pm
	Check the Magneto, It thats what uou have, It may be putting out a weak spark after it warms up