KZ650 Sleeper Build (KZ1000 engine transplant)

  • Scirocco
  • Scirocco's Avatar
  • Offline
  • Premium Member
  • Never change a running system
  • Posts: 4409
  • Thanks: 2259

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

04 May 2025 10:06
#912099
sf4t7 wrote:
I would be using the same mounting holes, bolts, and spacers.  They will bolt to a bracket I'll make attached to the frame.  Similar to Scirocco's first picture (behind the side cover).  Or I may decide to leave well enough alone!
 
Here is a closer look of my Accel coil mouning plate with the WG coil relay mod.

 
My 1975 Z 1 B 900 Project

www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
The following user(s) said Thank You: sf4t7

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

  • MFP-Joe
  • MFP-Joe's Avatar
  • Away
  • User
  • Posts: 226
  • Thanks: 257

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

04 May 2025 10:30 - 04 May 2025 10:31
#912101
I have never owned a Z1 but I have ridden them quite a few times. I like the torque the engine makes over the 650/750 but the bikes in general sit too high and I feel "small" on them. Even if a 1000 is lowered it is still heavier and physically bigger than a 650. I am only 5' 5" tall so I am more at home on the smaller bikes, a few of my 650's have lowered suspension.

The 650 had always been my preferred street bike but the engine just lacks low end grunt compared to the bigger engines. Even my 831cc 650 is no match to a worked on 1000. The big heavy crank just seems to have the perfect stroke for bigger pistons (over 70mm) and the 650/750 will never be able to replicate that. I have already built bigger version 650/750 engines and the power output is not the same.

I had a spare 1000 engine so I thought this would be my chance to make a torque monster that fits me physically.


Thanks for the explanation, it all makes sense to me: Seat height is a criterion! I`ve mostly thought, you all do that about shorter wheelbase and maybe better handling in curves, in combination with the stronger engine..
(But I rarely had to think about seatheigh, unless I was a bit too tall on some classic race bikes with my 6`1",...like on my former Bevel Ducati 900 MHR and 900 SS, where I always had to fold myself up a bit ;-)

And I completely agree with you: the Z1 engine is a great engine, as is the Z1000...Í´ve been riding those things since 1979 and still love them!Personally, I don't really like the 650cc engine with its plain bearings and the engine concept, I prefer roller bearing engines on my oldschool bikes ;-)
 
 
Greetings, Joe
Last edit: 04 May 2025 10:31 by MFP-Joe.

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

  • Injected
  • Injected's Avatar Topic Author
  • Offline
  • User
  • Posts: 1230
  • Thanks: 737

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

04 May 2025 14:38
#912109
Yeah, I am tip toes on a stock Z1 and it does not feel great when stopped on one foot. Once I get going its OK, and I can ride just about anything but prefer a smaller lighter bike.

Both the Z1 and the KZ650 were designed by the same engineer at Kawasaki. The 650 had a bunch of improvements with lessons learned on the Z1 including the frame design and a few things on the engine design. There are merits to both engine designs and without exploring those differences Kawasaki motorcycles would be drastically different today.
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
The following user(s) said Thank You: MFP-Joe, sf4t7, kimchella

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

  • sf4t7
  • sf4t7's Avatar
  • Offline
  • Sustaining Member
  • Posts: 750
  • Thanks: 558

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

04 May 2025 15:57
#912111
And a big block motor in the smaller frame is what hot rods are all about!   
[img
Scotty

1974 Z1A
Yoshimura 987
welded Z1 crank
Andrews 1X Cams
Delkevic 4 into 1
Superbike bars
530 conversion
The following user(s) said Thank You: MFP-Joe, Wookie58

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

  • Wookie58
  • Wookie58's Avatar
  • Offline
  • Moderator
  • Posts: 4839
  • Thanks: 2925

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

04 May 2025 16:28
#912112
sf4t7 wrote:
And a big block motor in the smaller frame is what hot rods are all about!   
[img
Check out the 2023 BOTY-Lee’s 1170 :)
1982 KZ1000 Ltd
www.kzrider.com/forum/11-projects/617631...-82-begins?start=192
kzrider.com/filebase-alias?view=download...d-fault-diagnosis&ca

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

  • MFP-Joe
  • MFP-Joe's Avatar
  • Away
  • User
  • Posts: 226
  • Thanks: 257

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

04 May 2025 22:30
#912121
Don't get me wrong: The 650 is certainly a more "modern" bike compared to the Z1, with a much better frame construct, and I really like its design, especially the first series in green,... but they was always "too small" for me.( I prefer 1500 mm wheelbase on all my bikes), And even though, for example, the under-mounted shims are the "safer" option, but I simply prefer to leave the camshafts in place when adjusting the valves and do the job from above. But everyone has their favorites.
Anyway, I really admire your great work with these engine transplants!
 
Greetings, Joe

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

  • Injected
  • Injected's Avatar Topic Author
  • Offline
  • User
  • Posts: 1230
  • Thanks: 737

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

05 May 2025 07:20 - 05 May 2025 07:23
#912128
wrote:
And a big block motor in the smaller frame is what hot rods are all about!   
[img


 
Yeah, the bigger the better, but for street use 1200 cc is pushing it.

When the stock Kawasaki barrel has to be opened up to accommodate a larger bore they are then subject to increased oil leakage. If I could go bigger without the threat of oil leakage I would. Diverting the oil out of the block and up to the head is a solution for the leak, but huge engines just run very hot. A true big block just can't cool the liners enough and the cases end up having very little clamping surface over 1200 cc.
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
Last edit: 05 May 2025 07:23 by Injected. Reason: sp

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

  • sf4t7
  • sf4t7's Avatar
  • Offline
  • Sustaining Member
  • Posts: 750
  • Thanks: 558

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

05 May 2025 07:32
#912130
Yeah Injected, by big block I meant 1000 / 1100 size motors as compared to the 650's.  Should have used the term "bigger motor"    
[img
Scotty

1974 Z1A
Yoshimura 987
welded Z1 crank
Andrews 1X Cams
Delkevic 4 into 1
Superbike bars
530 conversion
The following user(s) said Thank You: Injected

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

  • Injected
  • Injected's Avatar Topic Author
  • Offline
  • User
  • Posts: 1230
  • Thanks: 737

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

05 May 2025 10:19
#912134
If I could run a 1327 engine on the street I would, but it's too much of a gamble if its going to leak or not especially without it being dry blocked. Even my 1327 drag engine is not optimized, once you go bigger than 1200 you need to up the size on everything (valves/cams/carbs) or they just don't run right.

The difference between a 1200 and a 1327 is big, worse yet when you go to 1428, and crazy at 1500cc.
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
The following user(s) said Thank You: sf4t7, Dragbike_Mike

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

  • sf4t7
  • sf4t7's Avatar
  • Offline
  • Sustaining Member
  • Posts: 750
  • Thanks: 558

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

05 May 2025 11:37
#912138
Think I'll stick with my 987cc Z1,  I've always assumed it knows how to go a little faster than I know how to.  
[img
Scotty

1974 Z1A
Yoshimura 987
welded Z1 crank
Andrews 1X Cams
Delkevic 4 into 1
Superbike bars
530 conversion
The following user(s) said Thank You: Injected

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

  • Injected
  • Injected's Avatar Topic Author
  • Offline
  • User
  • Posts: 1230
  • Thanks: 737

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

05 May 2025 14:37
#912144
Yeah, that's the one thing about a stock KZ barrel is that it could be anything between 903 and 1260cc
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

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

  • Injected
  • Injected's Avatar Topic Author
  • Offline
  • User
  • Posts: 1230
  • Thanks: 737

Re: KZ650 Sleeper Build (KZ1000 engine transplant)

Today 19:11 - Today 19:13
#912225
I got a little bit accomplished on this build today.  

Was able to get the stator cover and sprocket cover installed. My first time bonding that damn rubber wedge into the cover where the wires come out, what a pain in the arse. Working on mostly 650/750 there is never a need to do this chore.

Got it done with some advice from a guy who has done hundreds, hopefully it won't leak!





I waited quite a while for the RTV to set up before tightening the cover bolts.



Found out that there is some sort of dimensional difference from the 1000 to the 650 on where the clutch rod sits, as the 650 clutch cable is now too long.
Had to run the cable inside the center of the triple tree to take up some length, and could not route the cable inside the frame like it would normally run. I will need to take some time to measure where the difference lie, I guess this is why a standard length chain was slightly short.





Normally on a 650 the upper portion of the clutch cable would go behind the speedo and the lower portion inside the lower frame rail next to the engine case. On this build there was no space between the frame rail and the case for the cable. I fished the upper portion of the cable where it would take up the most length to avoid a big arch on the lower portion. I will need to cover the spring with a section of rubber hose to protect the frame and use the stock clip cable minders where they make the most sense.
 
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
Last edit: Today 19:13 by Injected. Reason: info
The following user(s) said Thank You: Vinsky

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

Powered by Kunena Forum