Author Topic: Add Fuel Pickup to PD Carbs? Or Replacement Fuel value on early K Tanks?  (Read 895 times)

0 Members and 1 Guest are viewing this topic.

Offline KB02

  • Take it easy there, Sonny, I'm an
  • Old Timer
  • ******
  • Posts: 3,760
Is it possible to add an additional fuel inlet to the PD Carbs? On the earlier model carbs, the fuel inlet was part of the tube that connected the carbs together, but with the PD carbs, the fuel inlet has been molded into the #2 body.

Or, if that is not that easy to do, is there an aftermarket fuel valve that will easily fit onto an Early K model tank with a single fuel line leading off instead of two?
« Last Edit: June 24, 2018, 06:55:09 am by KB02 »
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"

Offline KB02

  • Take it easy there, Sonny, I'm an
  • Old Timer
  • ******
  • Posts: 3,760
bump...
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"

Offline robvangulik

  • Honda Fourever
  • Expert
  • ****
  • Posts: 1,417
Why?

Offline KB02

  • Take it easy there, Sonny, I'm an
  • Old Timer
  • ******
  • Posts: 3,760
I'm using a '72 tank on a '78 bike with the PD Carbs. The early tank has duel outputs, but the PD's only have a single inlet. I've been fighting some lean issues that, admittedly are probably jetting issues, but I wonder if they could be fuel starvation as well. Rather than plugging one of the outlets on the fuel valve like I have (and constantly watch it for a leak), I would like to use it to ensure I have enough fuel in the bowls.
OR, if the single inlet feeds enough gas for a highly modified engine, is there a replacement fuel valve with only a single outlet that I can easily replace the stocker with?
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"

Offline DaveBarbier

  • Really Old Timer ...
  • *******
  • Posts: 5,620
Doubt you’re having fuel starvation issues, but you can look into Pingel or Golan petcocks.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,805
My suggestion is to time how fast the single outlet fills a quart jar.   Then ask yourself if you want the bike to use that much fuel in the time you measured.  It will likely drain the tank completely in about 5-10 minutes.  You want to use that much fuel?

At any rate, single or dual outlet flow rates are so very close because they are sourced from the same diameter entry hole in both petcocks.  1 or 2 exits really don't matter.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
I never had a fuel starvation issue from lack of flow from the tank, and i'd bet the brass barb from the petcock, or the inlet barb on the carbs are the same ID for both bikes.
....one of these might come into play for you.

'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline KB02

  • Take it easy there, Sonny, I'm an
  • Old Timer
  • ******
  • Posts: 3,760
Doubt you’re having fuel starvation issues, but you can look into Pingel or Golan petcocks.

I'll have to take some measurements, but those Pingel adapter plates might be the trick to putting on a single outlet valve. Thanks for that tip.

Like I said, it's most likely just a jetting issue, but it's one of those thoughts that got into my head and just won't go away. You know?
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"