Results 1 to 2 of 2
  1. #1
    CB750 New Member drmccart's Avatar
    Join Date
    Apr 2019
    Location
    Vermont
    Posts
    1

    Diagnosing CB 750k issues (1979)

    Hi All,

    I bought a '79 cb750 last year and was able to get it running. However, I am having a lot of issues and I dont really know where to begin. My biggest issue that I am trying to solve for the moment appears to be a problem with the carburetors. Currently the bike does not start unless the choke is all the way out, and even then, requires a bit of throttle to keep it from dying on me. However, once the engine is hot It runs no problem ~hour. After an hour of riding, the engine idle is really high (no tachometer but if i had to guess it would be approximately 2500 rpm ish range?). I'm also going through spark plugs like its my job, so the engine appears to be running very rich.

    Im sure there is a lot wrong, but I would appreciate any suggestions on where to start.

    thanks

  2. #2
    CB750 Member NicksHonda's Avatar
    Join Date
    Apr 2018
    Location
    Sacramento, CA
    Posts
    21
    Start with the basics.

    What is your compression on each cylinder?
    What do your plugs look like? When were they last changed?

    While the carbs seem to be problematic and easily get junk in them, I would confirm the basics are good first.

    Are you sure you're running on all four cylinders?
    Sometimes the coils miss, or could be a bad wire/spark plug.

    Good luck.
    Havin' Fun in Sacramento!

    2006 BMW R1200RT
    2002 Honda CBR954RR
    1979 Honda CB750L

Similar Threads

  1. '78 750K carb rebuild issues
    By Nygma78 in forum Carburetors / Fuel
    Replies: 2
    Last Post: 08-07-2017, 05:23 AM
  2. 79 cb 750k
    By easydawg97 in forum The DOHC Garage (1979-1983)
    Replies: 9
    Last Post: 12-06-2016, 07:11 PM
  3. CB 750K
    By Johnnydodger in forum The CB750 Garage
    Replies: 3
    Last Post: 09-09-2015, 08:04 PM
  4. 1979 750k speedo stripped
    By r0dembos in forum The CB750 Garage
    Replies: 1
    Last Post: 07-31-2015, 04:50 AM
  5. 1979 750k full throttle and gas over flow issue??
    By BabaYaga in forum The DOHC Garage (1979-1983)
    Replies: 1
    Last Post: 04-03-2015, 09:30 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
  •