KZR's Bikes of the Month for 2024

650 SR 1981 (z750L engine)

  • gordone
  • Topic Author
  • Offline
  • Sustaining Member
More
22 Apr 2018 22:41 #782202 by gordone
Replied by gordone on topic 650 SR 1981 (z750L engine)
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



1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

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
  • Never change a running system
More
23 Apr 2018 00:06 #782205 by Scirocco
Replied by Scirocco on topic 650 SR 1981 (z750L engine)
The engine sounds great, a little out of sync but who cares. Nothing you can´t handle.
The following user(s) said Thank You: gordone

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

More
23 Apr 2018 11:13 #782236 by ajsfirehawk
Replied by ajsfirehawk on topic 650 SR 1981 (z750L engine)
At last the payoff, well done!

79 KZ650 SR
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.

More
23 Apr 2018 11:38 #782240 by Nessism
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
More
24 Apr 2018 23:33 #782332 by gordone
Replied by gordone on topic 650 SR 1981 (z750L engine)
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


1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

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
More
25 Apr 2018 12:23 #782359 by gordone
Replied by gordone on topic 650 SR 1981 (z750L engine)
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 :)

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine

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

More
25 Apr 2018 15:10 #782363 by Barry2
Replied by Barry2 on topic 650 SR 1981 (z750L engine)
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
More
26 Apr 2018 06:07 #782397 by gordone
Replied by gordone on topic 650 SR 1981 (z750L engine)

Barry2 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

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

  • gordone
  • Topic Author
  • Offline
  • Sustaining Member
More
01 Jul 2018 15:13 #786248 by gordone
Replied by gordone on topic 650 SR 1981 (z750L engine)
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.






1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

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
More
13 Jul 2018 05:41 - 13 Jul 2018 11:57 #786881 by gordone
Replied by gordone on topic 650 SR 1981 (z750L engine)
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....

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).

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.

More
13 Jul 2018 06:31 - 13 Jul 2018 06:32 #786888 by TexasKZ
Replied by TexasKZ on topic 650 SR 1981 (z750L engine)
Congratulations on killing an electrical gremlin. An intermittent problem can sometimes be really difficult to find.

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
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
More
13 Jul 2018 11:58 #786900 by gordone
Replied by gordone on topic 650 SR 1981 (z750L engine)

TexasKZ 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

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

Powered by Kunena Forum

If you like KZR Please consider making a donation. Thank you.

KZRider is free, but not without cost.

Please consider chipping in a few bucks to help cover the cost of running the KZR servers.