The EFI pump puts out way to much pressure for carbs.  As I recall the FI pump runs 60ish PSI, your FCRs want about 3.

Thanks Koko. I had posted in the "all about fuel tanks thread", was just in a hurry for feedback. The consensus seemed a bit inconclusive for this application.

Howie; I had also thought perhaps the fact that FCR carbs may be able to work without the pump because of the "accelerator pump" they have in tandem with the gravity. If I went with split carbs and short manifolds at some point this may still work? Just a thought.

I also like the idea of a carbed bike with an ECU handling ignition and fueling duties some day. Maybe when I build my dream Sport Classic.

Still trolling eBay for that tank...the plastic ones are so much more common. I want a NOS tank to go with my new everything else. They're such a bargain when they pop up, less than the cost of a professional paint job, and I need an extra tank anyway.

You would need to measure.  Fuel pump is better than gravity anyway, more consistent.  Assuming your not wanting to use the pentagon pump is based on aesthetics a well hidden small electric might be a good solution.

while the efi pumps build a lot of pressure, they don't actually flow that much.  if you try to empty a tank using the efi pump to pump it out it will take much longer than most people expect.

I use the efi pumps on carby ss no worries.  without a pressure head they just push the shit around.  just don't restrict it at all.

Just picked this bad boy up...



Think Imma black out the engine from the cases up, powder coat the S4R forks I haven't bought yet black, and add some more pop to go with the frame like a brushed aluminum pressure plate, sprocket cover, clutch slave etc. Paint the cowl to match the alu. fender.