Suzuki GS750 Mikuni VM26's on a Zephyr 750 & GPZ750 cam's in Zephyr750 head
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Suzuki GS750 Mikuni VM26's on a Zephyr 750 & GPZ750 cam's in Zephyr750 head
15 Oct 2024 02:56
Hi,
Currently figuring out how to attach Suzuki GS750 VM26's to a Zephyr 750 head.
Have the Z900/1000 rubber carb manifold's, elongated holes, bolts straight on.
Suzuki throttle bracket looks similar to Z900 and overlaps the rear cam tunnel bolt.
Bought a Z650 (KZ650) throttle bracket, it fits around the rear cam tunnel bolt.
Sure this has been done before and found a thread about it, but the actual question is about which cables/throttle tube to use, cannot find a clear example. At the moment I have 80's GPZ750 unitrac cables and throttle tube.
,
My bike is in the avatar , its a bit of a bitsa, 1979 Z650 frame, JMC chrome swingarm, later gpx600 forks, re worked micron fork brace, GPZ750 wheels.
Engine currently in bits, early 80's KZ750 cases (actually fits my frame, GPZ unitrac motor that came with bike had be bogged in) , GPZ750 barrels, 90's Zephyr 750 head.
My 80's GPZ750 unitrac engine needed a lot of cylinder head work, but luckily I found a Zephyr head that has been reconditioned, stripped it anyway and its all good for less than the price of a new set of valves and it has the Z900 look, will have to file the square fin profile to something more rounded , think it will look more at home in the Z650.
Question 2, I have read something about cam circles being different in some engines, so what do I check to determine if my GPZ unitrac cams will work correctly in my Zephyr head, it has same cam cover style as the Z900's.
Have added a few pictures below.
Currently figuring out how to attach Suzuki GS750 VM26's to a Zephyr 750 head.
Have the Z900/1000 rubber carb manifold's, elongated holes, bolts straight on.
Suzuki throttle bracket looks similar to Z900 and overlaps the rear cam tunnel bolt.
Bought a Z650 (KZ650) throttle bracket, it fits around the rear cam tunnel bolt.
Sure this has been done before and found a thread about it, but the actual question is about which cables/throttle tube to use, cannot find a clear example. At the moment I have 80's GPZ750 unitrac cables and throttle tube.
,
My bike is in the avatar , its a bit of a bitsa, 1979 Z650 frame, JMC chrome swingarm, later gpx600 forks, re worked micron fork brace, GPZ750 wheels.
Engine currently in bits, early 80's KZ750 cases (actually fits my frame, GPZ unitrac motor that came with bike had be bogged in) , GPZ750 barrels, 90's Zephyr 750 head.
My 80's GPZ750 unitrac engine needed a lot of cylinder head work, but luckily I found a Zephyr head that has been reconditioned, stripped it anyway and its all good for less than the price of a new set of valves and it has the Z900 look, will have to file the square fin profile to something more rounded , think it will look more at home in the Z650.
Question 2, I have read something about cam circles being different in some engines, so what do I check to determine if my GPZ unitrac cams will work correctly in my Zephyr head, it has same cam cover style as the Z900's.
Have added a few pictures below.
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Re: Suzuki GS750 Mikuni VM26's on a Zephyr 750 & GPZ750 cam's in Zephyr750 head
15 Oct 2024 06:45
Welcome to KZRider
Dave
Dave
Original owner 78 1000 LTD
Mr Turbo Race Kit, MTC 1075 Turbo pistons by PitStop Performance , Falicon Ultra Lite Super Crank, APE everything. Les Holt @ PDM's Billet Goodies . Frame by Chuck Kurzawa @ Logghe Chassis . Deep sump 5qt oil pan. RIP Bill Hahn
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- Wookie58
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Re: Suzuki GS750 Mikuni VM26's on a Zephyr 750 & GPZ750 cam's in Zephyr750 head
15 Oct 2024 07:09
Welcome from Leicestershire, interesting looking project

1982 KZ1000 Ltd
www.kzrider.com/forum/11-projects/617631...-82-begins?start=192
kzrider.com/filebase-alias?view=download...d-fault-diagnosis&ca
www.kzrider.com/forum/11-projects/617631...-82-begins?start=192
kzrider.com/filebase-alias?view=download...d-fault-diagnosis&ca
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- Injected
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Re: Suzuki GS750 Mikuni VM26's on a Zephyr 750 & GPZ750 cam's in Zephyr750 head
15 Oct 2024 20:35
Welcome from Canada.
For longer throttle cables on a 650 you can try those from a KZ1000 USA model, higher bars than Z1000 and Z650 UK bikes which provide more length.
As for the cam info on 750's see this : (bottom of pic)
For longer throttle cables on a 650 you can try those from a KZ1000 USA model, higher bars than Z1000 and Z650 UK bikes which provide more length.
As for the cam info on 750's see this : (bottom of pic)
1978 KZ650B2 w 1197cc Z1 engine
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
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- Mepb750
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Re: Suzuki GS750 Mikuni VM26's on a Zephyr 750 & GPZ750 cam's in Zephyr750 head
17 Oct 2024 00:53
Hi, Thank you for the cam information, took the base circle reference, did a search and found a posting on how to measure it.
Apparently it's the exhaust cam that has the smaller base circle.
quote from other post
" only the exhaust cam on the 83-86 Unitrac zx750's have a smaller base circle. The intake cam has a "normal" base circle exactly the same as any other kz750 or kz650 intake or exhaust camshaft."
www.kzrider.com/forum/2-engine/612384-ho...e-1983-gpz750#819840
Will go measure it, its a unitrac motor I stripped, so it might be it is the smaller exhaust cam in which case I cannot use it in my later Zephyr750 head.
Thanks again,
And hello everyone, that's a really nice looking GPZ fuel injected bike in the UK.
Apparently it's the exhaust cam that has the smaller base circle.
quote from other post
" only the exhaust cam on the 83-86 Unitrac zx750's have a smaller base circle. The intake cam has a "normal" base circle exactly the same as any other kz750 or kz650 intake or exhaust camshaft."
www.kzrider.com/forum/2-engine/612384-ho...e-1983-gpz750#819840
Will go measure it, its a unitrac motor I stripped, so it might be it is the smaller exhaust cam in which case I cannot use it in my later Zephyr750 head.
Thanks again,
And hello everyone, that's a really nice looking GPZ fuel injected bike in the UK.
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Re: Suzuki GS750 Mikuni VM26's on a Zephyr 750 & GPZ750 cam's in Zephyr750 head
17 Oct 2024 01:23
Quick update, using the rough method, caliper at 90 degree across the lobe, my exhaust cam is roughly 1mm shorter than the inlet cam, so it is a unitrac smaller base circle one.
Off to buy a set of zephyr 750 cams which will match the head I have.
Have to check what the power difference is, not too fussed about top speed etc, I usually ride around the surrey hills /country roads, so 60/70 mph on a good day is about it, way too old to play with the modern plastic missile brigade, they look great but suspect my back would last about a mile with clip-ons.
Thanks again.
Off to buy a set of zephyr 750 cams which will match the head I have.
Have to check what the power difference is, not too fussed about top speed etc, I usually ride around the surrey hills /country roads, so 60/70 mph on a good day is about it, way too old to play with the modern plastic missile brigade, they look great but suspect my back would last about a mile with clip-ons.
Thanks again.
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