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| Carburetor Idles Rough; Carter throws fuel at idle! | |
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| Tweet Topic Started: Jul 24 2013, 01:44 PM (2,313 Views) | |
| RMinPA | Jul 24 2013, 01:44 PM Post #1 |
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Need some expertise here. My restorer is stumped and wants to get a new Carb. Carb says Carter YF, stamped one place 1899 and lower 1-830. Was rebuilt professionally. Starts and runs but idles rough. When he looks down the throat raw gas is pumping out of the Accelerator Pump Discharge Valve. He replaced the diaphragm, bypassed the PCV Valve as a test, checked the valves but none were over-tightened and confirmed that the timing is correct. Any ideas what might be wrong? Everything else is ready to go on the Willys. The license plates are even mounted and this is the last glitch. Thanks for your help! |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| oldtime | Jul 24 2013, 06:13 PM Post #2 |
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First thing is that you need to correctly identify the carburetor. The information you provided is not correct and you have posted a Carter YF casting number. That information does not identify the carburetor in question. Please read here and pay close attention to proper component identification: http://z4.invisionfree.com/CJ3B_Bulletin_Board/ar/t2626.htm |
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Currently building my final F-134 powered 3B . Rock Crawler using factory parts from the Willys Motors era (1953-1963) http://s4.zetaboards.com/CJ3B_Bulletin_Board/topic/30228766/1/#new | |
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| ba25 | Jul 24 2013, 09:07 PM Post #3 |
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Rich offering pics of where to find carb model # stamped in rib as stated by OT These are YF carbs and model #s stamped on rib. ![]() |
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BA Agan 46 Bantam T3-C 2953 46 Bantam T3-C 19638 "Big Red" 49 CJ-2A 222564 51 M38 MC 28115 52 M100 285896 62 CJ5 57548-148683 64 DJ3A 8204-24210 | |
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| RMinPA | Jul 24 2013, 09:36 PM Post #4 |
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Thanks guys. I will call them tomorrow and get more information. Thanks! |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| RMinPA | Jul 25 2013, 08:21 AM Post #5 |
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Tom, the mechanic, says there's no flange with the lettering on it but he is certain that the carb we have IS the one pictured in his repair manual and parts catalogue as belonging in the vehicle. This, by the way, is a 1962. Might they have done away with that flange in those later years? So assuming that the carb is correct and correctly rebuilt, any ideas why raw gas is pumping out of the Accelerator Pump Discharge Valve during idle? Tom also confirmed those markings I'd quoted earlier with the 1899 on the Float Housing and the Carter YF. He also found 6-1870 up near the gas inlet. Any ideas or should we just ship in a new or rebuilt carb? |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| oldtime | Jul 25 2013, 09:33 AM Post #6 |
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No absolutely not. The thin reinforcement flange as shown in BA's pic is present on all model variations of the carter YF regardless of vintage or application. As you can clearly see all YF carburetors are not designated as 938. That condition specifically indicates missing or incorrectly adjusted pump discharge components. Those particular components are frequently missing due to previously performed rebuilds by unqualified repairmen. The correct pump discharge components are relative to the specific model of YF that you have. NOS Carter YF's for your application are extremely rare to locate. A so called rebuilt carburetor is a gamble dependant upon the rebuilers knowledge of correct specifications required for Hurricane engine application. I suggest you posatively identify the carburetor you have and repair it as required. I would like to thank BA and all others for posting their pics for the texted subject matter. Most here on this forum are aware that I am completely unable to upload any pics. |
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Currently building my final F-134 powered 3B . Rock Crawler using factory parts from the Willys Motors era (1953-1963) http://s4.zetaboards.com/CJ3B_Bulletin_Board/topic/30228766/1/#new | |
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| RMinPA | Jul 25 2013, 01:29 PM Post #7 |
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Thanks for all your help, everyone. My restorer finally got the image I'd sent so he will be checking the carb again this afternoon, then we will have more info. We tend to default to Carl Walck for parts. Is he the best source for Carburetor guts or is there a "Floyd the Carburetor Guy" out there somewhere? |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| div4gold | Jul 25 2013, 03:01 PM Post #8 |
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http://carburetorsonly.com/index.html These guys rebuilt my original carb. It was leaking at the throttle shaft, they rebushed that and did a rebuild. Purrs like a kitten now. |
Old retired fart living in Ione, WA. I have a 1964 CJ3B. Recently overhauled original motor, transmission and overdrive. 11" Bronco drum brakes on all 4. Needs a new coat of paint but that will have to wait till next summer, it's next summer and I'm working on that now UPS & FEDEX will continue to profit
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| RMinPA | Jul 25 2013, 03:52 PM Post #9 |
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More information. It is cast as a Carter YF and yet really does not seem to have that flange with the model #. My mechanic thinks it's a carb that's listed in his parts book for 1965 and later. In his book it starts with a "Z" ![]() ![]() ![]() New thoughts? |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| RMinPA | Jul 25 2013, 04:37 PM Post #10 |
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Just spoke to a "carburetor guy" who suggested we check the following before replacing the carb: 1. Vacuum Leak in Exhaust? 2. Too Much Fuel Pump Pressure? 3. Fuel Contamination: Tank, Lines, etc.? 4. Flow level too high? 5. Float no good? 6. Needle/Seat bad? 7. Points/Condenser 8. Cap/Rotor 9. Do not condemn carb until these are all checked. FYI that I just emailed to my mechanic. Thanks everybody! |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| oldtime | Jul 25 2013, 07:05 PM Post #11 |
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From your pic I can tell you this was not the standard carburetor for any 1962 vintage. This particular carburetor has a vented air horn assembly. That infers it's probably but not posatively a YF 4002 S. The YF 4002 S is basically intended for use with Hurricane engines having emmissions controls. (smog pump) The YF model 4002 series production begins very in late 1965 and ends in 1971. This carburetor was most likely removed from a 1966-1971 CJ5/6. Actually the complete tune up sequence should be followed before adjusting the carburetor. Perhaps someone can upload the tune-up sequence from the Universal Service Manual. (USM) |
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Currently building my final F-134 powered 3B . Rock Crawler using factory parts from the Willys Motors era (1953-1963) http://s4.zetaboards.com/CJ3B_Bulletin_Board/topic/30228766/1/#new | |
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| jyotin | Jul 25 2013, 07:32 PM Post #12 |
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Keep it simple... The primary reason that a YF dumps fuel is having the wrong float valve. Fuel dumping can be minor or serious, and can vary between the two at any particular time on the same carburetor. First, do what Ken says and get the proper carb. The 4002s was designed to operate with standard Jeep emissions systems. You want a YF with one of the following stamped into the webbing---938,938SA,938SC,938SD, with the 938SD being the latest and greatest Jeep carb. Once you have one of those, DON'T use Walcks kit to rebuild it. It will have the wrong parts. So will autozone, turners, o'reilleys, quadratec, 4 wheel drive hardware, debella, and _______________ (fill in the blank). I have never found the correct float valve anywheres but the carburetor shop. Even the carburetor shop has a float valve which is theoretically a thousandth or two too large, but the F-134 will tolerate that margin. There is only one place to get reliable rebuild kits for that carb. www.thecarburetorshop.com Sometimes you can find one on ebay, but if you don't know what you are looking for you will likely get the wrong thing. If you want to research this on your own you can; this topic gets covered about every 6 months or so on this site---- or you can simply go to the carburetor shop, tell them you have a YF for a 4 cylinder jeep with one of the above sub model numbers and he'll fix you with exactly what you need. best of luck... |
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It's just my luck that something good is going to happen to me today. 54 - 3B - down on the farm 67 - cj6 - former state of Alabama vehicle ?? - cj5 T98a - made from spare parts - Ford tractor blue ?? - cj5 T98a - made from spare parts - Jeep green | |
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| RMinPA | Jul 26 2013, 11:48 AM Post #13 |
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Thanks everyone. Seems we have the WRONG %$#%$& carb. No wonder it does not work! The Carb Shop will only do business M & Tu from 9-noon and 1-4 Central time so I am checking other vendors to find a 938 preferably SD that's freshly rebuilt. I will keep this thread updated until the thing is installed and running. Thanks again! |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| RMinPA | Jul 26 2013, 11:55 AM Post #14 |
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Would this work? http://www.amazon.com/gp/offer-listing/B00...ion=refurbished |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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| RMinPA | Jul 26 2013, 01:32 PM Post #15 |
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Or this? http://www.kaiserwillys.com/product/1111/w...rts-accessories |
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Rich Meyer 1962 CJ-3B Ser#57348 88612. Restoration finished 9/6/2013 to stock with factory optional wheels/tires and heater. Engine#807895 2007 JKU Rubicon on 37's, 4 1/2" Lift, 5.13s, etc. Now in Rockford IL | |
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UPS & FEDEX will continue to profit 


7:24 PM Jul 10