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Brand new Weber 45's, perplexing fuel issue


73G-nose

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Trying a first start on a brand new motor.

 

Have factory fresh Weber 45 dcoes on a TMW manifold. Fuel pump is a Carter 4070, making 4 psi with pump running. Float level and jets are as delivered, except for a change to 165 main jets.

 

Timing has been checked several times.

 

Fuel is reaching carbs, and is dripping from bowls.

 

Engine will fire, but won't catch...plugs removed and are bone dry. Fuel doesn't seem to be sufficiently reaching the combustion chamber. Using the chokes had no effect. Am I missing something obvious here?

 

Thanks for any and all advice.

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Latest update:

 

Removed carb 1 to verify accelerator pump operation...no fuel squirt from pump jets when butterflies pumped. Accelerator pump linkage bound up...lubricated linkage and was then getting fuel squirt during throttle pump.

 

Float level checked out okay, main jets clear.

 

Reinstalled carb 1, removed bowl covers on carbs 2 and 3, verified accel. pump linkage was free on both.

 

Ignition on, pump on...end result same. Intermittent firing but no start...plugs still dry.

 

Still seems to be something amiss in the carb starting circuit. Hoped to avoid pulling all three carbs off the manifold for a teardown, but now it seems unavoidable.

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Got it started. Had to do some further massaging to the accel. pump linkage, now getting a decent pump shot into the intake.

 

Just as an FYI, the ignition is a new Mallory Hyfire 6AL with matching coil, so spark strength was not one of my concerns.

 

These carbs were purchased through TEP, and I don't know if they were drop-shipped or came directly from their inventory, but wherever they came from it appears they had been on the shelf for quite some time.

 

Thanks for the replies.

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  • 2 weeks later...
  • 1 month later...
I dont think I have ever seen the start circuits hooked up on dcoe's. I usually just have to give it 2-3 good pumps on the pedal and she starts no problem. With the cam/compression I have it takes a while to be warm enough to go far, but it starts ok.

 

I'm in the same boat here. Choke on, couple of shots with the pedal and it'll fire up even on the coldest fall day. It's a bit tempermental until warm but that's to be expected when it's chilly out.

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