Re: 48 JD 'B' DLTX 71 Carburetor Bowl Vent
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Posted by Highland Joe on October 01, 1998 at 08:43:16:
In Reply to: 48 JD 'B' DLTX 71 Carburetor Bowl Vent posted by John Kerber on September 30, 1998 at 18:26:32:
: I recently bought about a 1948 all-fuel JD : Model B (serial number plate is gone)and : the carburetor kept flooding over even when sitting. : After many wasted hours, I realized the bowl : has to be vented or the gas just gets pushed out : into the intake. I double gasketed the bowl : and cut a slot in one of the gaskets to act as : a vent. : Sure enough, the carb no longet floods, but : it will not run smoothly at all. It actually runs : smoother with the carb flooding over. : At idle, it continuosly hunts and has a sharp : pop-pop instead of the thump-thump that I expect. : I soaked the carb a couple days but cannot get : what I think is the bowl vent clean(tiny hole on underside : of main body, inside of float bowl). Also, at idle, the : idle adjust screw has noe effect from wide open to all the : way closed. : Is venting the bowl through the gasket causing : me to run poorly or is something else? : Where exactly is the real vent, and where : does it vent to? : Thanks for any help. : john.kerber@ps.ge.com The reason for your poor idle is that the carb is still too rich ( too much fuel ). The idle circuit in your carb is probably not even being used ( butterfly valve open too far due to too much fuel from the main cct. ). I don't know that exact carb, but all carbs have small air bleed holes that allow air to mix with the fuel in both the idle and main cct. If these holes are plugged two thing can happen. The fuel circiuts will not work right and/or you will have a siphon effect that will draw fuel out of the float bowl and in to the venturi when the engine has stopped ( even if the float bowl is vented ). Be careful in cleaning the air bleed holes because if you enlarge them you will also affect the air/fuel mixture. Hope this helps.
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