Keihin CV34 Repair Kits
- calum
-
Topic Author
- Offline
- User
- Posts: 1136
- Thanks: 404
Re: Keihin CV34 Repair Kits
04 Oct 2020 13:55
I got the calipers out and it seems to be M6 x 0.75. That sound about right?
KZ1000 Restomod (
www.kzrider.com/forum/11-projects/614517-1977-kz1000-restomod
)
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
Please Log in or Create an account to join the conversation.
- Nessism
-
- Offline
- Sustaining Member
- Posts: 7571
- Thanks: 2939
Re: Keihin CV34 Repair Kits
04 Oct 2020 17:36 - 04 Oct 2020 19:56calum wrote: I got the calipers out and it seems to be M6 x 0.75. That sound about right?
No. It's not .75. I'll check the garage and look for the tap I bought. I want to say it's .5.
Edit: I was wrong. It's 6mm x .75. Mikuni BS carbs are 6mm x .5 thread. I mixed them up.
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
Last edit: 04 Oct 2020 19:56 by Nessism.
The following user(s) said Thank You: calum
Please Log in or Create an account to join the conversation.
- calum
-
Topic Author
- Offline
- User
- Posts: 1136
- Thanks: 404
Re: Keihin CV34 Repair Kits
23 Oct 2020 05:33
KZ1000 Restomod (
www.kzrider.com/forum/11-projects/614517-1977-kz1000-restomod
)
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
Please Log in or Create an account to join the conversation.
- calum
-
Topic Author
- Offline
- User
- Posts: 1136
- Thanks: 404
Re: Keihin CV34 Repair Kits
28 Oct 2020 14:36
I rebuilt a (thoroughly cleaned) second set of carbs with the kit. The main jet nozzles and the pilot screws were too big. It wasn't the threads on the pilot screws, the bottom section was too large for the hole in the carb body. Same deal with the nozzle, the nozzle section that is usually a press fit with the carb body was way too tight.
Here are the sections I'm talking about:
All the rest of the parts were fine and the float needles made it through the initial test (setting the float height). I got the carbs on the bike, vacuum synced them and set the idle.
Hoping for some fine weather tomorrow so I can get the bike out for a proper test.
Here are the sections I'm talking about:
Attachment main jet nozzle.jpg not found
Attachment idle screw.jpg not found
All the rest of the parts were fine and the float needles made it through the initial test (setting the float height). I got the carbs on the bike, vacuum synced them and set the idle.
Hoping for some fine weather tomorrow so I can get the bike out for a proper test.
KZ1000 Restomod (
www.kzrider.com/forum/11-projects/614517-1977-kz1000-restomod
)
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
Attachments:
Please Log in or Create an account to join the conversation.
- Irish Yobbo
-
- Offline
- User
- Posts: 380
- Thanks: 93
Re: Keihin CV34 Repair Kits
28 Oct 2020 14:51calum wrote: I rebuilt a (thoroughly cleaned) second set of carbs with the kit. The main jet nozzles and the pilot screws were too big. It wasn't the threads on the pilot screws, the bottom section was too large for the hole in the carb body. Same deal with the nozzle, the nozzle section that is usually a press fit with the carb body was way too tight.
Here are the sections I'm talking about:
All the rest of the parts were fine and the float needles made it through the initial test (setting the float height). I got the carbs on the bike, vacuum synced them and set the idle.
Hoping for some fine weather tomorrow so I can get the bike out for a proper test.
I had the same issue with the pilot screws, but the main jet nozzles were alright for me. They were tighter, but could still be pushed in and removed without much trouble.
I measured the pilot screws (at the end as you indicated, where they bind), and the stock ones measured ~3.00-3.04mm, and the ones from this kit measured ~3.07-3.20mm. The lower sizes (closer to 3.10) were usable, but the 3.20mm pilot screw had no chance of fitting.
I think these parts are generally pretty good, but the tolerances just aren't as tight as they need to be.
1981 KZ750 LTD
Please Log in or Create an account to join the conversation.
- calum
-
Topic Author
- Offline
- User
- Posts: 1136
- Thanks: 404
Re: Keihin CV34 Repair Kits
28 Oct 2020 14:54
Yeah, overall a pretty good kit - can't beat it for the price!
There was no way the nozzles were going in on my set - sanded one down a bit and tried some encouragement with a drift and a hammer, but it wasn't going in without damaging the end.
There was no way the nozzles were going in on my set - sanded one down a bit and tried some encouragement with a drift and a hammer, but it wasn't going in without damaging the end.
KZ1000 Restomod (
www.kzrider.com/forum/11-projects/614517-1977-kz1000-restomod
)
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
Please Log in or Create an account to join the conversation.
- Irish Yobbo
-
- Offline
- User
- Posts: 380
- Thanks: 93
Re: Keihin CV34 Repair Kits
28 Oct 2020 23:54calum wrote: Yeah, overall a pretty good kit - can't beat it for the price!
There was no way the nozzles were going in on my set - sanded one down a bit and tried some encouragement with a drift and a hammer, but it wasn't going in without damaging the end.
You got me thinking - I went out and looked at the remainder of my kit. I didn't fit the nozzles, I'd just forgotten. I don't think they fit either, same as you. So I ended up using most of the parts in the kit except for the nozzles and some of the pilot screws (my pilot screws were in a bad way, one needed to be removed with a bolt extractor).
1981 KZ750 LTD
Please Log in or Create an account to join the conversation.
- TexasKZ
-
- Offline
- Platinum Member
- Posts: 7749
- Thanks: 2362
Re: Keihin CV34 Repair Kits
29 Oct 2020 07:27
If those parts are so inaccurately machined, I wonder how accurate the jet orifices are.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
The following user(s) said Thank You: Nessism, calum
Please Log in or Create an account to join the conversation.
- calum
-
Topic Author
- Offline
- User
- Posts: 1136
- Thanks: 404
Re: Keihin CV34 Repair Kits
29 Oct 2020 08:29
I got out for a test today and the bike ran smoothly through the entire rev range for the first time since the rebuild. Seems like the other parts are accurate enough 
I imagine the jet orifices are a lot more uniform than the outer surfaces - given that they are basically just drilled holes. I'm not sure how close to the given sizes they are but I'll be putting a third set of carbs together soon and will have this set back off the bike, I'll see if I can get hold of some gauges to check the jet size against the stock jets in my first set of carbs.
For now the bike is running fine so I'm going to call that a win

I imagine the jet orifices are a lot more uniform than the outer surfaces - given that they are basically just drilled holes. I'm not sure how close to the given sizes they are but I'll be putting a third set of carbs together soon and will have this set back off the bike, I'll see if I can get hold of some gauges to check the jet size against the stock jets in my first set of carbs.
For now the bike is running fine so I'm going to call that a win

KZ1000 Restomod (
www.kzrider.com/forum/11-projects/614517-1977-kz1000-restomod
)
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
1977 KZ1000A1 ( www.kzrider.com/forum/11-projects/616901...-spare-parts-project )
1980 KZ750H ( kzrider.com/forum/11-projects/612054-kz750h-restoration )
2000 BMW F650GS
The following user(s) said Thank You: Nessism, undiablo
Please Log in or Create an account to join the conversation.