Author	[Modern View]
JGC 02-12-2013 06:52:15 67.8.21.168 Report to Moderator	Can a Model B be modified to use a duplex carb, as used on later generation JD tractors? If yes,,,, what is involved; carb, linkages, manifold, head, other components that need to be moved or modified, etc, etc??? Regards, JGC [Reply]   [No Email]
buickanddeere 02-15-2013 08:16:27 184.151.61.232 Report to Moderator	Re: Duplex Carb on a Model B in reply to JGC, 02-12-2013 06:52:15   Cheaper and run better, have live hydraulics plus the option of live pto and optional PS if you just trade the B for a 50 or 520. [Reply]  [No Email]
jd b puller 02-14-2013 15:19:00 65.190.129.111 Report to Moderator	Re: Duplex Carb on a Model B in reply to JGC, 02-12-2013 06:52:15   Agree with most of the comments. Not sure how it would be easier to tune as all the duplex carbs I've seen have fixed load jets with that single screw at the bottom that has very little impact on mixture. My experience with taking a 2 barrel carb, and modifying the manifold to adapt it to a single barrel Head was that it worked ok at wide open but will lose all bottom end unless the motor is really big. The 50 head has 10 head studs, the B has 9 and not in the same location. You can put a 50 block into a B with a little work. What goals are you trying to accomplish? [Reply]  [No Email]
jd b puller 02-12-2013 21:08:50 65.190.129.111 Report to Moderator	Re: Duplex Carb on a Model B in reply to JGC, 02-12-2013 06:52:15   Agree with most of the comments. Not sure how it would be easier to tune as all the duplex carbs I've seen have fixed load jets with that single screw at the bottom that has very little impact on mixture. My experience with taking a 2 barrel carb, and modifying the manifold to adapt it to a single barrel Head was that it worked ok at wide open but will lose all bottom end unless the motor is really big. The 50 head has 10 head studs, the B has 9 and not in the same location. You can put a 50 block into a B with a little work. What goals are you trying to accomplish? [Reply]  [No Email]
2-banger 02-12-2013 18:10:49 69.205.118.226 Report to Moderator	Re: Duplex Carb on a Model B in reply to JGC, 02-12-2013 06:52:15   you need a 50 hd..manifold and carb..50 hd feeds each cyl seperate where the orginal b hd only has 1 intake port both cyls draw from it.it will make a little more power and be easy to tune [Reply]  [No Email]
gtx1967jewison 02-12-2013 20:45:22 174.254.240.71 Report to Moderator	Re: Duplex Carb on a Model B in reply to 2-banger, 02-12-2013 18:10:49   Imo a single carb is easier to tune. Especially a dltx v.s. a duplex. All my singles idle nicer & slower than most duplex tractors at the shows. Half as much to go wrong & if it plugs you can actually access the ports to clear them. [Reply]  [No Email]
Mike M 02-13-2013 07:38:45 24.140.0.120 Report to Moderator	Re: Duplex Carb on a Model B in reply to gtx1967jewison, 02-12-2013 20:45:22   I would imagine that most of those with the duplex carbs. have not been adjusted correctly. Like you said they are harder to tune. You need to short out each cyl. and adjust each cyl.to idle at the same RPM. [Reply]  [No Email]
Mike M 02-12-2013 07:37:44 24.140.0.120 Report to Moderator	Re: Duplex Carb on a Model B in reply to JGC, 02-12-2013 06:52:15   Only thing gained is a better idle. Not really any HP differance between a model B and a 50 [Reply]  [No Email]
John T 02-12-2013 07:31:06 71.52.99.130 Report to Moderator	Re: Duplex Carb on a Model B in reply to JGC, 02-12-2013 06:52:15   Not that Im aware of....Its the MANIFOLD thats important, I think the duplex carbs and duplex mainfolds have seperate chambers for each cylinder while the old single barrell manifolds dont. Thats why at slow idle (on single carbs and manifolds) if you pull one plug wire it almost dies while if you pull the other one it dont seem to make much difference NOT SO on duplex carbs with a seperate carb barrell and manifold chamber for each clinder....... Am I correct???? John T [Reply]  [No Email]