Author	[Modern View]
Wingswd 07-28-2012 08:45:44 67.142.168.24 Report to Moderator	Working on a 62 Series 3 D17 with a slight exhaust backfire. Plugs show #3 being very lean. wires are new, compression good, head is off and valves are alright. Any ideas and what plugs should it have in it. [Reply]   [No Email]
old 07-28-2012 11:08:16 209.86.226.40 Report to Moderator	Re: D17 lean on #3 in reply to Wingswd, 07-28-2012 08:45:44   If running lean on just one cylinder that almost has to be something wrong with the manifold as in a clog or a crack. Spark plugs will not change a rich or lean condition. Now then a intake valve that does not open as wide as it should would or even an exhaust valve not opening as it should would cause that. As for the back fire that is the by product of it running lean   [Reply]  [No Email]
Wingswd 07-29-2012 06:44:04 67.142.168.24 Report to Moderator	Re: D17 lean on #3 in reply to old, 07-28-2012 11:08:16   Thanks old, I'm just going to keep checking things. Lap the valves, set the valves, get it all back together and hope for the best. As for the plugs I just wanted to make sure I had the right ones in it.   [Reply]  [No Email]
old 07-29-2012 09:04:05 209.86.226.32 Report to Moderator	Re: D17 lean on #3 in reply to Wingswd, 07-29-2012 06:44:04   Another thing that could have cause that is a bad manifold gasket and leaking air at the #3 intake area of it   [Reply]  [No Email]
Wingswd 07-29-2012 18:38:53 67.142.168.23 Report to Moderator	Re: D17 lean on #3 in reply to old, 07-29-2012 09:04:05   I thought of that but 3 and 4 share a port   [Reply]  [No Email]
BushogPapa 07-29-2012 19:42:31 173.88.51.117 Report to Moderator	Re: D17 lean on #3 in reply to Wingswd, 07-29-2012 18:38:53   At that point, you need to "think like a JD Man".! All the older 2-cylinder JD's with a Single throat carb has the same problem.. The Leading cylinder Hogs the majority of the inlet charge and the trailing cylinder "Loafs".. That would not normally be a problem..but..IF you had a leaking gasket...there could end up being a Lean condition.. And, as OLD said..even a worn cam lobe or worn cam bearings could cause these symptoms.. Ron..   [Reply]  [No Email]
BushogPapa 07-29-2012 19:40:09 173.88.51.117 Report to Moderator	Re: D17 lean on #3 in reply to Wingswd, 07-29-2012 18:38:53   At that point, you need to "think like a JD Man".! All the older 2-cylinder JD's with a Single throat carb has the same problem.. The Leading cylinder Hogs the majority of the inlet charge and the trailing cylinder "Loafs".. That would not normally be a problem..but..IF you had a leaking gasket...there could end up being a Lean condition.. And, as OLD said..even a worn cam lobe or worn cam bearings could cause these symptoms.. Ron..   [Reply]  [No Email]
Wingswd 07-30-2012 19:21:33 67.142.168.24 Report to Moderator	Re: D17 lean on #3 in reply to BushogPapa, 07-29-2012 19:40:09   Thanks to both that does make sense   [Reply]  [No Email]