1980 KZ750-E1 Mikuni Carbs

  • 80KZ750E
  • 80KZ750E's Avatar Topic Author
  • Offline
  • User
  • Posts: 3
  • Thanks: 0

1980 KZ750-E1 Mikuni Carbs

15 Sep 2019 18:15
#810901
I recently acquired a 1980 KZ750-E1. It hadn't been operated for over 10 years, so I was pretty sure there would be carb issues. I've reviewed information that I could find online and in manuals and have since taken the carbs apart. As I dig deeper into this project, I have realized all of the information related to KZ750's from this era seem to be fore Keihin cv34 carbs, not the Mikuni's that are on my specimen.
Can anyone tell me if I've got an odd ball that may have been modified along the way? It's pretty much stock and in-tact overall with less and 8,000 miles. The only real modification is a Kerker 4-1 exhaust.
I have to replace at least one jet, and I also will need the associated rebuild kits overall for these Mikuni's. Additionally, one of the diaphragms at the top of Carb 2 has some perforations in it, so I need to at least replace it.
Any advice or direction is appreciated. Even if you can recommend an economical carb upgrade, I may consider that.

Please Log in or Create an account to join the conversation.

  • Nessism
  • Nessism's Avatar
  • Offline
  • Sustaining Member
  • Posts: 7507
  • Thanks: 2870

Re: 1980 KZ750-E1 Mikuni Carbs

15 Sep 2019 18:23
#810902
Your bike came with Keihin's so obviously someone changed them to Mikuni's.

I would NOT replace the jets in the carbs now, clean them and reuse. Get all NEW O-rings, and float bowl gaskets if yours are in poor shape.

This carb rebuild tutorial may help. Follow all steps, including unganging the carbs. Short cuts are long cuts when it comes to carbs. If you follow this tutorial you will KNOW they are properly clean.
zeus.mtsac.edu/~cliff/storage/gs/Mikuni_...Rebuild_Tutorial.pdf

Please Log in or Create an account to join the conversation.

  • 80KZ750E
  • 80KZ750E's Avatar Topic Author
  • Offline
  • User
  • Posts: 3
  • Thanks: 0

Re: 1980 KZ750-E1 Mikuni Carbs

16 Sep 2019 11:47
#810932
Thank you Nessism! I'll take your advice and proceed as the instructions say.
Just curious, are the Mikuni any better/preferable to the Keihin? I know the guy I got the bike from is a GS fanatic, so it's not surprising that the instructions you linked to have a GS on the cover.
It's a work-in-progress, but I'll get it there...

Please Log in or Create an account to join the conversation.

  • DoctoRot
  • DoctoRot's Avatar
  • Offline
  • Sustaining Member
  • Oh, the usual... I bowl, I drive around...
  • Posts: 2545
  • Thanks: 680

Re: 1980 KZ750-E1 Mikuni Carbs

16 Sep 2019 14:11
#810934
can you post some photos of the carbs you have? they will help with identification

Please Log in or Create an account to join the conversation.

  • Nessism
  • Nessism's Avatar
  • Offline
  • Sustaining Member
  • Posts: 7507
  • Thanks: 2870

Re: 1980 KZ750-E1 Mikuni Carbs

16 Sep 2019 16:40
#810939
Given my druthers I'd take the Mikuni's. I like the choke system better among other things. That said, the driveability of my KZ750 is pretty much flawless so there is nothing wrong with the Keihin's, although they are more difficult to maintain.

Please Log in or Create an account to join the conversation.

  • 80KZ750E
  • 80KZ750E's Avatar Topic Author
  • Offline
  • User
  • Posts: 3
  • Thanks: 0

Re: 1980 KZ750-E1 Mikuni Carbs

16 Sep 2019 18:31
#810945
As requested by DoctoRot, here are some pictures. First is of them still on the bike. The next one has it cleaned up a bit. Third pic shows it on the bench. Last pic has the bowls off and some of the internals removed.
Pilot jet is a 42.5, main jet is a 125.
I unfortunately striped one of the pilot jet's, so I'm wrestling with it and how to extract it (it's way down in). Any suggestions are welcomed. I'm at the point of planning to buy an easy-out and mildly heat the aluminum body to try and get it out. It's been soaking in penetrating oil for days now.
Since the bike has the Kerker 4-into-1 pipe and the post-stock Mikuni carbs, are there any suggestions on what the jet sizes should be? Do these look workable?

Attachments:

Please Log in or Create an account to join the conversation.

  • Rick H.
  • Rick H.'s Avatar
  • Offline
  • User
  • Posts: 840
  • Thanks: 241

Re: 1980 KZ750-E1 Mikuni Carbs

24 Sep 2019 03:58
#811250
Not to steal the thread here, but the tutorial Ed posted on rebuilding these carbs is really helpful. Is there something similar for the VM26's on a '77 KZ-1000?
Thanks....Sorry for the interruption.
Rick H.
Rick H.

1977 Kawasaki KZ-1000A1

Please Log in or Create an account to join the conversation.

  • Nessism
  • Nessism's Avatar
  • Offline
  • Sustaining Member
  • Posts: 7507
  • Thanks: 2870

Re: 1980 KZ750-E1 Mikuni Carbs

24 Sep 2019 04:59
#811255
Rick H. wrote: Not to steal the thread here, but the tutorial Ed posted on rebuilding these carbs is really helpful. Is there something similar for the VM26's on a '77 KZ-1000?
Thanks....Sorry for the interruption.
Rick H.

It's not as detailed Rick but this may help... members.dslextreme.com/users/bikecliff/i.../vm_carb_rebuild.pdf

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum