Page 3 of 3 FirstFirst 123
Results 41 to 50 of 50
  1. #41
    CB750 Guru amc49's Avatar
    Join Date
    Sep 2015
    Location
    Fort Worth TX.
    Posts
    3,008
    If the ethanol in fuel answer was yes then the idle jet hole size is such that they tend to clog when the ethanol makes the fuel dry up faster. Bike then won't idle, no fuel. Those holes are like .013" or so in size and they can still have fuel in them even if carb is drained, capillary action keeps them with a drop of fuel covering the opening. It then dries and clogs the hole.

  2. #42
    CB750 Addict Medyo Bastos's Avatar
    Join Date
    Oct 2012
    Location
    Mid South
    Posts
    191
    Agreed; take the the jets out out and blow carb cleaner through them. From the inside out works better for me when cleaning jets. I prefer the walmart brand supertech carb cleaner the best. A little bit goes a long way.


    Sent from my iPhone using Tapatalk

  3. #43
    CB750 Enthusiast wingedwheel's Avatar
    Join Date
    Jul 2017
    Location
    Waterford, MI
    Posts
    44
    I found this thread which I thought was very good. http://forums.sohc4.net/index.php?topic=48858.0#top

  4. #44
    CB750 Enthusiast wingedwheel's Avatar
    Join Date
    Jul 2017
    Location
    Waterford, MI
    Posts
    44
    I am also looking for the countershaft oil seal. The part # is 91203-393-003. It lists as a 32x64x13. I found a 32x64x10 that I replaced it with but I’m seeing oil leaking out when I run the engine and I’m highly suspect of that being the culprit. Anyone know where to possibly get this NLA seal?

  5. #45
    CB750 Guru amc49's Avatar
    Join Date
    Sep 2015
    Location
    Fort Worth TX.
    Posts
    3,008
    That seal may be complicated by having to match with another one if like the DOHC is, the two fit together then create an oil chamber that supplies the big output bearing with oil. The illustrated parts list seems to show one like that.

    If your distance collar has wear on it the seal being new still cures nothing. The collar as well can leak on the ID where the seal has no impact.

  6. #46
    CB750 Enthusiast wingedwheel's Avatar
    Join Date
    Jul 2017
    Location
    Waterford, MI
    Posts
    44
    I don’t think it’s different than the SOHC, just a different size? In any case is there an odd parts supplier that I might get lucky with?

  7. #47
    CB750 Guru amc49's Avatar
    Join Date
    Sep 2015
    Location
    Fort Worth TX.
    Posts
    3,008
    I for one would not know.

    https://www.partzilla.com/catalog/ho...h-countershaft

    Pic there of '78 automatic shows both seals, parts 28 and 30. They work as a pair. On the DOHC it was always a problem, one time you would get the entire two piece affair and other times they only sent the outer part of it. On the DOHC they snap together to make one part. Can't say on the automatic.

    There is also a part 29 seal that is not picced and who knows what that one does? Your X13 and X10 thing is likely a thickness of seal issue, one is 1/8" thicker than the other likely.
    Last edited by amc49; 07-01-2020 at 10:28 PM.

  8. #48
    CB750 Enthusiast wingedwheel's Avatar
    Join Date
    Jul 2017
    Location
    Waterford, MI
    Posts
    44
    Yes AMC49 that is the only difference. I totally missed that inner on the diagram(I think) and I see it is still available. I wisely ordered two of the outer I found I think the issue is I have to split the case to get the inner out.

  9. #49
    CB750 Guru amc49's Avatar
    Join Date
    Sep 2015
    Location
    Fort Worth TX.
    Posts
    3,008
    Clarity of the issue is not helped out by the way Honda does things there. You wonder if the different seals are because they changed something there and you just need one of the right one. I had fits with DOHC until I figured out what they were doing there, it helped to have one of the seals fall apart in my hands too, to be able to recognize the two parts separately. While the DOHC is not an automatic SOHC, Honda tends to make changes that sometimes show across different product lines, it being part of the evolution of things.

  10. #50
    CB750 Enthusiast wingedwheel's Avatar
    Join Date
    Jul 2017
    Location
    Waterford, MI
    Posts
    44
    Yes I had a parts guy tell me that this bike uses parts and pieces from other models. Almost like they had something they wanted to try so why not just throw it on this odd man out machine. In hindsight I do remember looking at that seal and I actually have it in the drawer I was just reluctant to split that case when everything was apart. Now it looks like I have no choice. Outsmarted myself once again.

Page 3 of 3 FirstFirst 123

Similar Threads

  1. Bringing another one back from the grave.
    By K2750tracy in forum Builds
    Replies: 13
    Last Post: 12-16-2015, 07:19 PM
  2. Replies: 23
    Last Post: 09-19-2015, 05:26 PM
  3. For Sale - 1978 CB750A
    By Dain in forum Classifieds
    Replies: 0
    Last Post: 07-25-2014, 07:46 PM
  4. For Sale - Back up
    By Medyo Bastos in forum Classifieds
    Replies: 5
    Last Post: 11-19-2012, 05:59 AM
  5. Bringing an 82 CB750K back from the dead....
    By witttom in forum Carburetors / Fuel
    Replies: 10
    Last Post: 05-17-2012, 05:44 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
  •