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Author Topic: Carb or fuel issues ?  (Read 1689 times)

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Offline maximushuntermus

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Carb or fuel issues ?
« on: June 05, 2013, 06:28:32 PM »
So I'm just getting my L head fired up after a partial over haul, rings and valves. I bought a WO carter carb on ebay rebuilt. Got her fired up, verified oil pressure roughly set timing, but hard to keep running. Seems the choke has to be on, even after warming to 180, also it cuts out at like half throttle like its starving for fuel. I have a fuel line dropped into a gas can as this is just a make sure all is good and rolling chassis complete. I have the single action fuel pump with glass bowl, I can see fuel in there all the time about half way up glass. I don't have a spacer plate on fuel pump as I understood that was only for dual action pumps with vacuum. Oh one other item I did check the float to make sure it is set to 3/8" as is correct. I know these problems can be hard to diagnose but any ideas are appreciated.

Offline Bob W

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Re: Carb or fuel issues ?
« Reply #1 on: June 05, 2013, 09:25:59 PM »
Test the fuel pump. For a CJ-3A it should produce 2-1/2 to 3-3/4 PSI and pump 1 pint of fuel in 20-30 seconds.
Bob W

Offline athawk11

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Re: Carb or fuel issues ?
« Reply #2 on: June 06, 2013, 11:02:27 AM »
If you are getting the fuel to the carb that Bob has listed, then you will want to start looking at the carb.

The half throttle may be roughly where the 'high speed' curcuit is kicking in on the Carb.  The high speed jet might have some debree in it.

Does it smooth back out at full throttle? 

Was the Carter pre adjusted by the Ebay builder?  You may need to adjust the idle and the fuel air mixture.

Good starting points are 2 turns in on the idle adjustment...(back of the throttle linkage) and 1.5 turns out for the idle mixture...(front side spring loaded screw), then adjust from there.

Tim
2-1949 CJ3As
1-1946 CJ2A

Offline maximushuntermus

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Re: Carb or fuel issues ?
« Reply #3 on: June 06, 2013, 09:26:02 PM »
Thanks guys, I pulled the fuel line and cranked it seemed to be pumping good volume, put thumb over end and felt like real good pressure the pump was barand new. Not sure what adjustments the builder put on it I will ask him I have been chatting with him also. I can't get it to full throttle it starts cutting out at half throttle or so, not an electrical cut out just seems like fuel. I tried pumping the throttle getting the rpms up then opening the choke and it just dies it has to have the choke or she does not cook the water ha haha..The front side brass spring loaded screw seems to have no effect when adjusting in or out so that may be a clue huh?

Offline maximushuntermus

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Re: Carb or fuel issues ?
« Reply #4 on: June 08, 2013, 03:17:11 PM »
I noticed underneath the metering jet or orifice, its the jet at very bottom of bowl, under that jet was a ball bearing just peaking out of the port or passage it rides in. It seemed to be binding in there or maybe its not supposed to go into the channel that comes back up side of carb. Is it supposed to ride in that port some kind of shut off in a roll over? Or does it just roll around under the jet and free float, or is the darn thing even supposed to be it there?

Offline athawk11

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Re: Carb or fuel issues ?
« Reply #5 on: June 08, 2013, 11:05:20 PM »
Max,
I don't remember there being anything under that jet when I rebuilt my Carter.  There is a jet that has a small ball bearing, but it doesn't go in the bottom of the fuel bowl. 

Nothing personal on the eBay seller, but it may be worth it to send your carb to scoutpilot here at the 3A.  Let him give it the once over.  I've heard nothing but good about the work he does on these Carter's.

Tim
2-1949 CJ3As
1-1946 CJ2A