650 SR 1981 (z750L engine)
- gordone
-
Topic Author
- Offline
- Sustaining Member
-
Registered
- Posts: 1496
- Thanks: 86
Re: 650 SR 1981 (z750L engine)
22 Apr 2018 22:41
Yesterday I finish the bike (almost), and started it up. It started up easy and all pistons was online. I took the bike out on a short 30 minutes drive.
It was going great I was not higher then 5k RPM, vary the RPM all the time, I can feel it need a carb sync, but will take that later when I have the valves
under control. I will re torque the head bolts before next time. I will check the valves but not eraly, don`t want to do it to many times...
Video from one of the first time it starts:
streamable.com/ge8ub
It was going great I was not higher then 5k RPM, vary the RPM all the time, I can feel it need a carb sync, but will take that later when I have the valves
under control. I will re torque the head bolts before next time. I will check the valves but not eraly, don`t want to do it to many times...
Video from one of the first time it starts:
streamable.com/ge8ub
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Attachments:
Please Log in or Create an account to join the conversation.
- Scirocco
-
- Offline
- Premium Member
-
Registered
- Never change a running system
- Posts: 4409
- Thanks: 2268
Re: 650 SR 1981 (z750L engine)
23 Apr 2018 00:06
The engine sounds great, a little out of sync but who cares. Nothing you can´t handle.
My 1975 Z 1 B 900 Project
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode
The following user(s) said Thank You: gordone
Please Log in or Create an account to join the conversation.
- ajsfirehawk
-
- Offline
- Sustaining Member
-
Registered
- Posts: 511
- Thanks: 89
Re: 650 SR 1981 (z750L engine)
23 Apr 2018 11:13
At last the payoff, well done!
79 KZ650 SR
80 KZ1000 Z1 Classic
83 KZ1100 LTD
Z900RS
23 Mach 1
80 KZ1000 Z1 Classic
83 KZ1100 LTD
Z900RS
23 Mach 1
The following user(s) said Thank You: gordone
Please Log in or Create an account to join the conversation.
- Nessism
-
- Offline
- Sustaining Member
-
Registered
- Posts: 7733
- Thanks: 3115
Re: 650 SR 1981 (z750L engine)
23 Apr 2018 11:38
Great job. Congratulations!
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
The following user(s) said Thank You: gordone
Please Log in or Create an account to join the conversation.
- gordone
-
Topic Author
- Offline
- Sustaining Member
-
Registered
- Posts: 1496
- Thanks: 86
Re: 650 SR 1981 (z750L engine)
24 Apr 2018 23:33
Yesterday have I installed petrol hoses on the air breath port on the carbs to avoid water when I wash the bike etc...
I just have let the end of the hoses end up in front of the battery under the gas tank, I think that should be fine?
I need find a hose for the air breather also....
I have started a threat when it comes for house to the air breather also.
www.kzrider.com/forum/2-engine/608276-hose-oil-breather
I just have let the end of the hoses end up in front of the battery under the gas tank, I think that should be fine?
I need find a hose for the air breather also....
I have started a threat when it comes for house to the air breather also.
www.kzrider.com/forum/2-engine/608276-hose-oil-breather
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Attachments:
Please Log in or Create an account to join the conversation.
- gordone
-
Topic Author
- Offline
- Sustaining Member
-
Registered
- Posts: 1496
- Thanks: 86
Re: 650 SR 1981 (z750L engine)
25 Apr 2018 12:23
Got problem to start the bike today, I have written down everything here:
www.kzrider.com/forum/2-engine/607610-st...uild?start=20#782354
Hope somebody have some good idea I can look into tomorrow morning, want out driving
www.kzrider.com/forum/2-engine/607610-st...uild?start=20#782354
Hope somebody have some good idea I can look into tomorrow morning, want out driving

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Please Log in or Create an account to join the conversation.
- Barry2
-
- Offline
- User
-
Registered
- Posts: 126
- Thanks: 23
Re: 650 SR 1981 (z750L engine)
25 Apr 2018 15:10
Did you perchance get those two hoses switched?
1976 KZ900
Please Log in or Create an account to join the conversation.
- gordone
-
Topic Author
- Offline
- Sustaining Member
-
Registered
- Posts: 1496
- Thanks: 86
Re: 650 SR 1981 (z750L engine)
26 Apr 2018 06:07Barry2 wrote: Did you perchance get those two hoses switched?
Double checked today, no that is not the problem.
I have removed the hoses for ventilation, until I got the engine up and running again.
Since I have a threat for starting up the engine I fill inn all information I have for the problem here:
www.kzrider.com/forum/2-engine/607610-st...uild?start=20#782396
Thank you for using your private time for helping me out...
My heads is screamin for driving in the nice weather

When it started so easy for 3 days ago it was to easy.. heh
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Please Log in or Create an account to join the conversation.
- gordone
-
Topic Author
- Offline
- Sustaining Member
-
Registered
- Posts: 1496
- Thanks: 86
Re: 650 SR 1981 (z750L engine)
01 Jul 2018 15:13
Long time since last update here, I have posted around on the forum for getting support / inputs but not here, so I wanted to make a summary what I have done the last months. I have been on a weekend, really nice trip. The bike worked "okay", middle range and low range are in period bad.... no good proportional control over the engine force... But the trip was great anyway
you find a way around it and adapt
I started driving on Friday after work and on Sunday on my way home, when I started in the morning I observed the start engine almost was not strong enough to start the bike and 2 hours later I killed the engine while waiting for a traffic light and then I was not able start it... My first time starting a bike from pulling it... and it was sand on the road... after some attempt I learned second gear was easier hehe 
It turned out the charge voltage is low and the start solenoid don`t always work
I have now replaced the regulator and the charge voltage is good, maybe to high, need to check more up there, its close to 15v...
I installed a serial type regulator, a upgrade, it shall be more soft to the stator also.
Old regulator:
New regulator:
The unstable engine, some times it was working perfect, but most of the time it was not.... idle off.. issue...start up on cold engine only 3 and 4 cylinders fires after some throttle both started.... problem in the middle range... I have tried going up one step in pilot and also rise the needle one step... without any improvement...
After some talking on the forum I figure out the needle previous owner has installed was wrong, and when I have tinked over it... I have never understand the float 100%,
because when I have measured the height with clear tube, it has been good, but then some gas could come out and then stopp.... strange....
So I ordered new seat and needle for all four carbs and installed.. and then I adjusted the height best I could....
When I started up first time it was a new sound to the engine on cold engine... and when I could switch of the choke after some seconds and the bike dont die... these was new for me
Today have I driven a 1-2 hours trip.. and the engine is working really good compare to before ! good proportional control, quick throttle respond.. stable rage in whole RPM range.... I need to drive more before I trust the engine 100%, but It looks good ! 
Next thing is to install a fuse between the regulator and battery, now it`s going direct.



It turned out the charge voltage is low and the start solenoid don`t always work

I have now replaced the regulator and the charge voltage is good, maybe to high, need to check more up there, its close to 15v...
I installed a serial type regulator, a upgrade, it shall be more soft to the stator also.
Old regulator:
New regulator:
The unstable engine, some times it was working perfect, but most of the time it was not.... idle off.. issue...start up on cold engine only 3 and 4 cylinders fires after some throttle both started.... problem in the middle range... I have tried going up one step in pilot and also rise the needle one step... without any improvement...
After some talking on the forum I figure out the needle previous owner has installed was wrong, and when I have tinked over it... I have never understand the float 100%,
because when I have measured the height with clear tube, it has been good, but then some gas could come out and then stopp.... strange....
So I ordered new seat and needle for all four carbs and installed.. and then I adjusted the height best I could....
When I started up first time it was a new sound to the engine on cold engine... and when I could switch of the choke after some seconds and the bike dont die... these was new for me


Next thing is to install a fuse between the regulator and battery, now it`s going direct.
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Attachments:
Please Log in or Create an account to join the conversation.
- gordone
-
Topic Author
- Offline
- Sustaining Member
-
Registered
- Posts: 1496
- Thanks: 86
Re: 650 SR 1981 (z750L engine)
13 Jul 2018 05:41 - 13 Jul 2018 11:57
I have had some strange problem with the Electrical power in general. When I switch om the keyswitch no light turn on, shaking on left power cable up to the front light It sometimes come back....
So today have I tried to fine the problem, I have erlier checked out the key swith.
Anyway IT turned out one cable wad broken off.... now I’m ready for some driving
OMLT problem I know about now is a turn light I need to replace 
Good feeling
I wanted to add some photos, but for some reason it was not possible from the cellphone today....
So today have I tried to fine the problem, I have erlier checked out the key swith.
Anyway IT turned out one cable wad broken off.... now I’m ready for some driving


Good feeling

I wanted to add some photos, but for some reason it was not possible from the cellphone today....
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Last edit: 13 Jul 2018 11:57 by gordone.
Please Log in or Create an account to join the conversation.
- TexasKZ
-
- Offline
- Platinum Member
-
Registered
- Posts: 7914
- Thanks: 2485
Re: 650 SR 1981 (z750L engine)
13 Jul 2018 06:31 - 13 Jul 2018 06:32
Congratulations on killing an electrical gremlin. An intermittent problem can sometimes be really difficult to find.
Happy riding.
Happy riding.
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
Last edit: 13 Jul 2018 06:32 by TexasKZ.
Please Log in or Create an account to join the conversation.
- gordone
-
Topic Author
- Offline
- Sustaining Member
-
Registered
- Posts: 1496
- Thanks: 86
Re: 650 SR 1981 (z750L engine)
13 Jul 2018 11:58TexasKZ wrote: Congratulations on killing an electrical gremlin. An intermittent problem can sometimes be really difficult to find.
Happy riding.
Thank you

I’m happy the bike has not stopped on one of my resent trips

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Please Log in or Create an account to join the conversation.
Moderators: Street Fighter LTD