« previous next »
Pages: [1]   Go Down

Author Topic: Keihin 022a carb limitations?  (Read 1382 times)

0 Members and 1 Guest are viewing this topic.

Offline rumpleblumpkinz

  • Full Member
  • *
  • Posts: 54
Keihin 022a carb limitations?
« on: January 28, 2017, 06:31:57 am »
Hi fellas,
  Recently bought a stock 74 CB550 and am in the process of restoring/modifying it. Needs head gaskets and oil seals so I figure I'll go ahead and do some mods while it's apart.

Performance plans so far:
4-1 exhaust system
Uni pods intake
Dynoman 10:1 big bore kit (also mod deck height to set squish band)
Webcam street cams
Probably mild port/ valve work as well

My question - will properly rejetted 022a's be up to the task? Has anyone run a set up similar to this with 022a's? In my experience the flow potential of stock carbs is generally underrated, and a proper reject can supply a mild street build with enough air/fuel. Opinions? I realize that worst case scenario of running these mods with the 022a's is a bottleneck situation, which isn't a deal breaker for me because I could always swap out to bigger carbs down the road. As of now, a carb swap isn't feasable with all the other work/mods I have ahead of me right now.

- Tom
« Last Edit: January 28, 2017, 01:20:49 pm by rumpleblumpkinz »
Logged

Offline calj737

  • Really Old Timer ...
  • *******
  • Posts: 20,960
  • I refuse...
Re: Keihin 022a carb limitations?
« Reply #1 on: January 28, 2017, 06:36:51 am »
Member Flatlander has a 550 motor running a similar cam, 59mm Wisecos, Mike Rieck stage 2-3 head and uses stock carbs. Makes some pretty impressive power from it (for a 550). I believe he even runs +1mm intake valves.

The head on that motor is THE bottleneck. Depending upon the work you do, components and am, the stock carbs properly jetted should be fine for a street bike.
Logged
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline flatlander

  • Old Timer
  • ******
  • Posts: 2,604
Re: Keihin 022a carb limitations?
« Reply #2 on: January 28, 2017, 06:50:13 am »
yes, what cal says and +1mm intake valves and i use the 069a carbs that came with my 550f. stock airbox with OEM paper filter.
so far i don't see the carbs as a bottleneck. i run them now with stock jetting which was fine in the beginning but noticed over the summer (it was especially hot here) some hesitation on high revs (+/- 9k rpm). will try some smaller main jets soon.
in my current setup the bottleneck would be the stock 4-1 exhaust.

rumple, put up a project thread, i'd be interested to follow along!
Logged

Offline Camrector

  • Hot Shot
  • ***
  • Posts: 580
Re: Keihin 022a carb limitations?
« Reply #3 on: January 28, 2017, 03:50:57 pm »
I run the 022as on my 605cc with mild port job and the cb650cam. Motor screams. Carbs have 0 limitations for my application and I think your going to be great as well. Actually had to drop a slow jet size and a main jet size due to the larger vacuum created by the bore.
Logged
Pages: [1]   Go Up
« previous next »