« previous next »
Pages: [1]   Go Down

Author Topic: cb550 won't rev over 4k  (Read 2162 times)

0 Members and 3 Guests are viewing this topic.

Offline np750

  • Full Member
  • *
  • Posts: 7
cb550 won't rev over 4k
« on: June 21, 2012, 02:06:39 PM »
just rebuilt the carbs and got them back on the bike, it idles great, really smooth around 1800 rpm but will not rev over 4k. with the choke on it will rev up to the redline with no problem.

what should i check first?
Logged

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: cb550 won't rev over 4k
« Reply #1 on: June 21, 2012, 02:15:40 PM »
Check that you aren't operating the choke backwards.

Lever down is is off and is the run position when warmed up. 
« Last Edit: June 21, 2012, 02:18:05 PM by TwoTired »
Logged
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 lucky

  • Really Old Timer ...
  • *******
  • Posts: 6,715
Re: cb550 won't rev over 4k
« Reply #2 on: June 21, 2012, 02:17:09 PM »
Quote from: np750 on June 21, 2012, 02:06:39 PM
just rebuilt the carbs and got them back on the bike, it idles great, really smooth around 1800 rpm but will not rev over 4k. with the choke on it will rev up to the redline with no problem.

what should i check first?

Idle at 1800???That is way too high.
Please tell us the YEAR of your CB550.

Can you please give us all the facts???

Intake type.
Exhaust type.
main jet size.
Idle jet size.
needle clip position.
mixture screw- turns out.


« Last Edit: June 21, 2012, 02:20:34 PM by lucky »
Logged

Offline np750

  • Full Member
  • *
  • Posts: 7
Re: cb550 won't rev over 4k
« Reply #3 on: June 21, 2012, 03:01:18 PM »
Quote from: TwoTired on June 21, 2012, 02:15:40 PM
Check that you aren't operating the choke backwards.

Lever down is is off and is the run position when warmed up.

  :-[  that was it right there.  next question, the way the carbs are set up the choke is kept in the open (cold start) position by the springs on the linkage if that makes sense. basically you have to hold the choke closed as opposed to holding it open. does anyone have a detailed picture of how this should be set up?


Logged

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: cb550 won't rev over 4k
« Reply #4 on: June 21, 2012, 06:50:28 PM »
There is supposed to be a spring and ball detent on the #1 carb opposite the choke lever side to hold the choke is the position set.

I've got a picture in the camera, if necessary.  But, a carb parts exploded drawing should show it better.

If you can't get the idle lower than 1800, then you may have the slide adjusters all skewed so far the slides can't close.  Did you you use the awful drill bit method to bench sync carbs?
Logged
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 np750

  • Full Member
  • *
  • Posts: 7
Re: cb550 won't rev over 4k
« Reply #5 on: June 21, 2012, 09:34:48 PM »
Quote from: TwoTired on June 21, 2012, 06:50:28 PM
There is supposed to be a spring and ball detent on the #1 carb opposite the choke lever side to hold the choke is the position set.

I've got a picture in the camera, if necessary.  But, a carb parts exploded drawing should show it better.

If you can't get the idle lower than 1800, then you may have the slide adjusters all skewed so far the slides can't close.  Did you you use the awful drill bit method to bench sync carbs?
i did not have that ball on my carbs when i got the bike, had no idea it existed, thanks for the help.

ya i just synced them tonight and i got it down to round 1,000ish
Logged

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,050
  • WHAT?no gravy?
Re: cb550 won't rev over 4k
« Reply #6 on: June 22, 2012, 02:26:59 AM »
get familiar with the correct fuel tap settings aswell,,off/on/res(reserve).
Logged
Pages: [1]   Go Up
« previous next »