Results 1 to 6 of 6
  1. #1
    CB750 New Member bertness72's Avatar
    Join Date
    Sep 2020
    Location
    Newtown, CT
    Posts
    2

    Exclamation Carb assembly stuck in engine manifold!

    Hi all, new guy Rob here. Writing about my '92 Nighthawk 750. I am in the process of removing the carb assembly and it will not budge from the engine. I removed the airbox and the choke cable. All the clamps are loosened, just about to fall off. I shot some WD40 around the intake boots and let it sit for an hour... still will not loosen up. I searched the shop manuals for FAQ's regarding this, scoured the internet for videos regarding same, and looked into other blogs. No dice.
    Has anyone out there had this same issue? What's the fix? Did I miss a secret screw or a phantom bolt somewhere?
    Any help/advise would be greatly appreciated.
    Thanks in advance...
    Rob

  2. #2
    CB750 Guru amc49's Avatar
    Join Date
    Sep 2015
    Location
    Fort Worth TX.
    Posts
    3,234
    Enough mileage the carb manifolds have cooked hard as rock to crack in pieces when you finally get carbs off. Not unusual.

  3. #3
    CB750 Member fg1972's Avatar
    Join Date
    May 2019
    Location
    Australia
    Posts
    25
    Try using a heat gun to warm up the rubber boots.


    Sent from my iPhone using Tapatalk

  4. #4
    CB750 New Member bertness72's Avatar
    Join Date
    Sep 2020
    Location
    Newtown, CT
    Posts
    2

    Cool

    Hi, Thanks for the tip. I tried it and it worked well.
    I pulled the carb assembly out and went to town. Had a challenge with the slow jets. They were completely clogged. Let them soak in carb cleaner for 2 days, now they look like brand new.
    Any suggestions on how to clean the varnish off the floats? Is it a bad idea to soak the plastic pieces in the carb cleaner? If they are submerged will they fill up with fluid???
    Thanks for your time.
    Rob

  5. #5
    CB750 Member fg1972's Avatar
    Join Date
    May 2019
    Location
    Australia
    Posts
    25
    Glad it worked. Not sure if carb cleaner is harmful to the the plastic floats if left immersed for a long time but you could try wiping them down with the stuff. I know thinners and acetone is often used to get the varnish out of fuel tanks but again, not sure if they’ll hurt the plastic. Leaving them for a while in some fuel might soften the varnish and probably a safer option to try first. Whatever you do immerse them in, if it gets inside the floats, that suggests the floats are leaking and should be replaced. Hope this helps.


    Sent from my iPhone using Tapatalk

  6. #6
    CB750 Guru amc49's Avatar
    Join Date
    Sep 2015
    Location
    Fort Worth TX.
    Posts
    3,234
    Carb cleaner is not as destructive as acetone but there is a small amount of acetone in all fuel. I'd try soaking one float only in acetone and if it damages it you will know quick enough. May not hurt it at all. The floats are thinking nylon and acetone won't touch them.

    Like said they will not leak fuel in if they are OK.

Similar Threads

  1. return spring assembly help
    By cbrianroll in forum Carburetors / Fuel
    Replies: 18
    Last Post: 06-20-2020, 06:50 PM
  2. ‘74 SOHC carb on a ‘80 DOHC engine
    By CjMarty in forum The CB750 Garage
    Replies: 4
    Last Post: 09-10-2019, 05:29 PM
  3. Shorty exhaust installed directly off of manifold?
    By polyclot in forum The SOHC Garage (1969-1978)
    Replies: 10
    Last Post: 05-25-2016, 08:01 PM
  4. Throttle assembly issues.
    By Jrowley1986 in forum The CB750 Garage
    Replies: 10
    Last Post: 03-22-2013, 12:41 AM
  5. Intake Manifold Inquiry - Please help!
    By Vossero in forum Carburetors / Fuel
    Replies: 1
    Last Post: 12-31-2012, 08:16 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •