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Mikuni 28mm?????
- flhwesty
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23 Jun 2013 13:29 #593584
by flhwesty
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
Mikuni 28mm????? was created by flhwesty
I pick these up at a swap meet. At first I though they are for a 78 Z1R. But they have a dual feed. When I got home I measured them, 27mm.
My questions are:
1. Are they 28s?
2. What are they off of?
My questions are:
1. Are they 28s?
2. What are they off of?
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
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- Patton
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- KZr Legend
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23 Jun 2013 15:11 #593596
by Patton
1973 Z1
KZ900 LTD
Replied by Patton on topic Mikuni 28mm?????
Guessing 26mm used on '76KZ900.
Excellent, user-friendly carbs, before the stringent environmental regulations came along.
Should perform well on a 1977 KZ1000.
Good Fortune!
Excellent, user-friendly carbs, before the stringent environmental regulations came along.
Should perform well on a 1977 KZ1000.
Good Fortune!
1973 Z1
KZ900 LTD
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- gd4now
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23 Jun 2013 15:35 #593600
by gd4now
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
Replied by gd4now on topic Mikuni 28mm?????
Hard to tell from the pics can only see an air screw - not sure if there are pilot screws on the bottom or not. If they have both they are vm26ss carbs from a Suzuki as they had both types of adjustment screws, while the 26s used on the Kawasaki's did not have both.
There were some 28s used on the Kaw's that had double fuel inlets with the large idle adjustment screw on top like yours have.
There should be some IDs stamped on the carbs either on the flange under the choke lever or on the same flange on the outside of #4 carb. They may help to Id them.
When you measure them you need to do so where the slide meets the carb throat and not at the intake bell or exit bell.
There were some 28s used on the Kaw's that had double fuel inlets with the large idle adjustment screw on top like yours have.
There should be some IDs stamped on the carbs either on the flange under the choke lever or on the same flange on the outside of #4 carb. They may help to Id them.
When you measure them you need to do so where the slide meets the carb throat and not at the intake bell or exit bell.
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
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- flhwesty
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23 Jun 2013 19:15 #593639
by flhwesty
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
Replied by flhwesty on topic Mikuni 28mm?????
This is ID stamp. I never knew these carbs had them. Thanks. Is there a chart with these ID stamps on them?
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
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- flhwesty
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23 Jun 2013 19:42 #593642
by flhwesty
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
Replied by flhwesty on topic Mikuni 28mm?????
ID stamp.
Attachment New_1_2013-06-23_17-14-32_2013-06-23.jpg not found
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
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- turboguzzi
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23 Jun 2013 19:49 #593643
by turboguzzi
Replied by turboguzzi on topic Mikuni 28mm?????
VM26SS indeed, they are actually 27mm bore like you measured
very nice and well made carbs,
very nice and well made carbs,
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- gd4now
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23 Jun 2013 19:52 #593645
by gd4now
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
Replied by gd4now on topic Mikuni 28mm?????
OK I have not see one with a Z as the first character like that, but then I have not see all the carbs there are.
It is my understanding that all of the 12xx ID carbs are vm28ss carbs other than those with a 1202 ID which are vm26ss carbs.
Having said all of that I do not mean to imply I know all there is to know about the IDs on the vm26ss and vm28ss carbs. I have been trying to build a table or data set regarding the stamped IDs on them. Though I do have several different IDs currently, I do not have enough to post a table as of yet. I do have one and have posted it for the vm24ss and vm22ss carbs used on the (K)Z650s.
I suggest you measure them, where the slide meets the carb throat. Can do so with several different methods. Use a socket that is less than 28mm od but more than 26mm od. Pull up or remove the slide and see if it fits. If it fits it is a 28 if not it is a 26. You could also use a set of calipers or cut plastic or cardboard circles of the appropriate size and see if they fit.
It is my understanding that all of the 12xx ID carbs are vm28ss carbs other than those with a 1202 ID which are vm26ss carbs.
Having said all of that I do not mean to imply I know all there is to know about the IDs on the vm26ss and vm28ss carbs. I have been trying to build a table or data set regarding the stamped IDs on them. Though I do have several different IDs currently, I do not have enough to post a table as of yet. I do have one and have posted it for the vm24ss and vm22ss carbs used on the (K)Z650s.
I suggest you measure them, where the slide meets the carb throat. Can do so with several different methods. Use a socket that is less than 28mm od but more than 26mm od. Pull up or remove the slide and see if it fits. If it fits it is a 28 if not it is a 26. You could also use a set of calipers or cut plastic or cardboard circles of the appropriate size and see if they fit.
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
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- turboguzzi
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24 Jun 2013 18:53 #593752
by turboguzzi
Replied by turboguzzi on topic Mikuni 28mm?????
VM26ss do not have any taper in the bore, if they are 27mm id then they are the 26ss.
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- flhwesty
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24 Jun 2013 21:32 #593780
by flhwesty
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
Replied by flhwesty on topic Mikuni 28mm?????
OK. Thanks
I was hoping 28mm for my Z1R.
Would be nice if we had a data base of the ID numbers on Mikunis. These could be for Suzuki too, I got these from a drag racer.
I was hoping 28mm for my Z1R.
Would be nice if we had a data base of the ID numbers on Mikunis. These could be for Suzuki too, I got these from a drag racer.
1983 GPZ750
1977 KZ1000LTD
1978 Z1R
1981 GPz1100 KZ1100-B1
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- gd4now
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24 Jun 2013 22:59 - 24 Jun 2013 22:59 #593804
by gd4now
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
Replied by gd4now on topic Mikuni 28mm?????
I beg to differ - it is my understanding that all of the vm Mikuni carbs do have a taper on the bore - otherwise there would be no venturi effect and no real pressure difference that allows for the fuel to be pushed or pulled up into the carb.
I am not saying they are not vm26ss carbs, but I would measure them to see just what size they are. I for one would like to know to add this ID to my data set.
I am not saying they are not vm26ss carbs, but I would measure them to see just what size they are. I for one would like to know to add this ID to my data set.
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
Last edit: 24 Jun 2013 22:59 by gd4now.
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- turboguzzi
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25 Jun 2013 09:01 #593848
by turboguzzi
Replied by turboguzzi on topic Mikuni 28mm?????
no problem GD, and I have no way to demonstrate that i am more knowledgeable than you. just about 35 years +/- working on bikes, road race tunning and plenty of carb racks everywhere....
so do i need to take a photo of a VM26SS straight bore for you to believe me or you'll take my word for it?
most performance oriented carbs (and the VM26SS were quite performance oriented, just not as much as 28 smoothbore VMs) have straight bores and a venturi created upon air ENTERING the carb). the more touring oriented carbs (like the VM's of KZ650s, the ones with the ribs), had the venturi enlarge also on the engine side for even more slow speed response/less top end flow.
so do i need to take a photo of a VM26SS straight bore for you to believe me or you'll take my word for it?
most performance oriented carbs (and the VM26SS were quite performance oriented, just not as much as 28 smoothbore VMs) have straight bores and a venturi created upon air ENTERING the carb). the more touring oriented carbs (like the VM's of KZ650s, the ones with the ribs), had the venturi enlarge also on the engine side for even more slow speed response/less top end flow.
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26 Jun 2013 04:10 #593971
by gd4now
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
Replied by gd4now on topic Mikuni 28mm?????
Turbo - first I do not know if you do or do not have more knowledge than I do, but I think it is rather presumptuous on your part to assume that you do. I have also been wrenching and racing bikes for just a little longer than you have been - about 45 years and like you I too have been through many different carbs in that time. So as you say I can not demonstrate to you that I have more knowledge than you do.
And I will say there is indeed a difference in the diameter of the intake bell opening and the throat where the slide meets it. It is this narrowing that creates the venturi effect (pressure differential) that allows fuel to be pulled up into the carb throat.
I have attached a pic of a set of vm26ss carbs - you tell me is the opening at the intake bell larger or the same size as throat is where the slide meets it.
And I will say there is indeed a difference in the diameter of the intake bell opening and the throat where the slide meets it. It is this narrowing that creates the venturi effect (pressure differential) that allows fuel to be pulled up into the carb throat.
I have attached a pic of a set of vm26ss carbs - you tell me is the opening at the intake bell larger or the same size as throat is where the slide meets it.
1977 KZ650 B1
Pods and Denco header
OLD KAW OWNERS SMILE ALOT
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