Z2 750 crank (Bossie the Kaw)

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15 Feb 2019 14:45 #798736 by SWest
Replied by SWest on topic Z2 750 crank (Bossie the Kaw)
Got the new headset. Can't wait to use it on long rides. :woohoo:
Steve

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16 Feb 2019 17:30 #798790 by SWest

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04 Mar 2019 13:59 #799703 by SWest
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Started working on the head again. Used the exhaust valves to "tip" them for my current head. Still have the Doremi valves for this one.
Steve

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04 Mar 2019 16:54 #799724 by SWest
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Found another tap and helicoils I bought in the high desert last year for my daughter's car.
Steve

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06 Mar 2019 06:33 #799812 by SWest
Replied by SWest on topic Z2 750 crank (Bossie the Kaw)
Was watching some videos where a crankcase and other parts were welded this way. If it works I'll be one step closer to a new head for Bossie. Too low a melting point to build up the combustion chamber edge on the one cylinder but I think skimming the head might compensate for that. Maybe even the block and a larger Liska idler roller above the cam chain adjuster to keep the timing spot on. :unsure:
Steve

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13 Mar 2019 22:07 - 13 Mar 2019 22:18 #800314 by ROADSTAR
Replied by ROADSTAR on topic Z2 750 crank (Bossie the Kaw)
Wow! Great build/read.

Just discovered this thread 2 days ago while I was pipe dreaming. I'm from the Philippines and currently own a 1975 Kawasaki 750RS ZII/Z2. Mine had a funny story actually. It was posted in one of the local motorcycle groups simply as "Kawasaki 900". Side covers had the 900 emblem as well, and papers simply had it listed as "Kawasaki 900".

Paid the seller up front and took the bike home for cleaning. However..... upon brushing off the engine.... it says "746cc". Worse, the wiring diagram/tool pan in the tail is in Japanese and actually says Z2. Not that I'm complaining, just a fun/interesting story. Bike's been with the family for over 30 years... original owner who passed away might be rolling in his grave right now.. all his life he probably has been showing it off as a "Kawasaki 900" when in fact it's not a Z1, but a Z2! lol

Anyway, was pipedreaming of a possible 76x58mm high revving Z2.. couldn't find results when searching in Japanese too - luckily, I stumbled upon your build. Sad you ditched the Z2 crank.... anyway, bike sounds good and seems real fast!!! how much more for an 1105cc! (I know someone locally who owns a Z1R with an 1105cc Wiseco kit, Mikuni RS36 carbs,as well as a real deal Kerker sidewinder exhaust installed.)

Good job with the Z!!!!! Hope I come up with the funds I need to either rebuild the bike as a 746, or actually realize my 76x58mm high rpm screamer pipe dream, or just get the 1105cc engine. Need to work harder it is!

Thank you for the great read, Steve!


PS

attached pictures of my bike before bringing it home

1985 Kawasaki  Ninja GPZ900R A2 「997cc」
1975 Kawasaki 750RS ZII 「746cc」

POWERED BY:
【川崎重工業】

夜露死苦!
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Last edit: 13 Mar 2019 22:18 by ROADSTAR.
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13 Mar 2019 22:36 #800315 by SWest
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Keep the parts, that Z2 could be worth more than a Z1. The 750 sleeves fit the 903 barrels so I had them bored to 1015. I'd get KZ 1000 barrels and if need relieve the case a bit to accept them. May not have to. You could stay 1015 or have them bored to 1105.
The bike ran great with the 750 crank and I still have it in the shed.
Pics, more pics. :woohoo:
Steve

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13 Mar 2019 22:48 #800316 by ROADSTAR
Replied by ROADSTAR on topic Z2 750 crank (Poser)

SWest wrote: Keep the parts, that Z2 could be worth more than a Z1. The 750 sleeves fit the 903 barrels so I had them bored to 1015. I'd get KZ 1000 barrels and if need relieve the case a bit to accept them. May not have to. You could stay 1015 or have them bored to 1105.
The bike ran great with the 750 crank and I still have it in the shed.
Pics, more pics. :woohoo:
Steve


Yes, the Z2 was always more valuable than the Z1. On Yahoo Auctions, a pristine, preserved one is currently posted at JPY 12,000,000 which is well over USD 100,000.

Welp, would love to post more pics but currently I just have the tank/sidecovers/tail on my table, and the whole front disassembled.. still thinking if I should get 18/18 wire wheels, get new fork inners/oil/dust seals, or just take the easy way out... order the whole front and rear end off of a Zephyr X.. (closest looking wheels to Dymags which costs around USD 2,000 for a set!!!)

Current problem with the bike is when my mechanic and I was supposed to change the engine oil, the cam chain guide fell along with the oil..... yikes!

1985 Kawasaki  Ninja GPZ900R A2 「997cc」
1975 Kawasaki 750RS ZII 「746cc」

POWERED BY:
【川崎重工業】

夜露死苦!

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14 Mar 2019 10:22 #800336 by SWest
Replied by SWest on topic Z2 750 crank (Bossie the Kaw)

ROADSTAR wrote: Wow! Great build/read.

Just discovered this thread 2 days ago while I was pipe dreaming. I'm from the Philippines and currently own a 1975 Kawasaki 750RS ZII/Z2. Mine had a funny story actually. It was posted in one of the local motorcycle groups simply as "Kawasaki 900". Side covers had the 900 emblem as well, and papers simply had it listed as "Kawasaki 900".

Paid the seller up front and took the bike home for cleaning. However..... upon brushing off the engine.... it says "746cc". Worse, the wiring diagram/tool pan in the tail is in Japanese and actually says Z2. Not that I'm complaining, just a fun/interesting story. Bike's been with the family for over 30 years... original owner who passed away might be rolling in his grave right now.. all his life he probably has been showing it off as a "Kawasaki 900" when in fact it's not a Z1, but a Z2! lol

Anyway, was pipedreaming of a possible 76x58mm high revving Z2.. couldn't find results when searching in Japanese too - luckily, I stumbled upon your build. Sad you ditched the Z2 crank.... anyway, bike sounds good and seems real fast!!! how much more for an 1105cc! (I know someone locally who owns a Z1R with an 1105cc Wiseco kit, Mikuni RS36 carbs,as well as a real deal Kerker sidewinder exhaust installed.)

Good job with the Z!!!!! Hope I come up with the funds I need to either rebuild the bike as a 746, or actually realize my 76x58mm high rpm screamer pipe dream, or just get the 1105cc engine. Need to work harder it is!

Thank you for the great read, Steve!


PS

attached pictures of my bike before bringing it home


Those look like VM 26 carbs. I'd like to see a better pic of the stator cover too. Automotive shocks? The crash bars look beefy. B)
Steve

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14 Mar 2019 12:44 #800339 by hardrockminer
Replied by hardrockminer on topic Z2 750 crank (Bossie the Kaw)
I think you're right on the carbs. VM26SS. The original carbs were VM26SC with the same flat tops and the Z1's. I prefer the SS carbs because they are simpler to set up and maintain. But for originality I have to use the SC carbs.

I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.

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14 Mar 2019 13:11 #800341 by SWest
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I didn't know the carbs were smaller. The valves, cams and other parts were the same as the Z1. The bores were thicker due to the smaller displacement. I saw a set at Sam's cycle. I'll ask about them when I pick up the Z1 front end he has there. Our new member's user name is ROADSTAR but the bike was really called Roadster.
At the time I didn't now what I had. I would have taken better care of it.
Steve
www.freewebs.com/750rs/z2.htm

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14 Mar 2019 14:49 #800352 by hardrockminer
Replied by hardrockminer on topic Z2 750 crank (Bossie the Kaw)
Early Z2 carbs had the big drain nut on the bottom. They switched to the slotted drain screw on the side (Similar to late Z1A & Z1B) during the first year.

Both models had the same cylinders but Z1 was 66 mm bore and Z2 was 64 mm. Early Z2 cylinders were like the early Z1's....no O ring groove on the top. They probably changed both designs at the same time. Does yours have the groove?

I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.

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