Saving a 1980 750 twin.

Scirocco
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Never change a running system

29 Jul 2019 13:01 - 29 Jul 2019 13:02 #808365 by Scirocco

Replied by Scirocco on topic Saving a 1980 750 twin.

I would put an oil cooler on the "To-Do-List" first. Bronze bushing the connecting rod for the wrist pin is a must have mod for tuned engines.
High Performance engines had and extra oil line (Jet) that spayed oil to the bottom of the piston and wrist pin for cooling and lubrication.

My 1975 Z 1 B 900 Project

www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode

Last edit: 29 Jul 2019 13:02 by Scirocco.

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DoctoRot
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Oh, the usual... I bowl, I drive around...

29 Jul 2019 13:34 #808366 by DoctoRot

Replied by DoctoRot on topic Saving a 1980 750 twin.

Hmmm, I wonder if it would be possible to make that happen

'78 1000 Long Term Project
'80 750G
750 Twin Big Bore Track Bike

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SWest
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10 22 2014

29 Jul 2019 14:12 - 30 Jul 2019 09:22 #808368 by SWest

Replied by SWest on topic Saving a 1980 750 twin.

This is for the cam chain in my daughter's car. It sprays in two directions.
Steve

Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229

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Last edit: 30 Jul 2019 09:22 by SWest. Reason: sp

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bluej58
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The chrome don't get you home

29 Jul 2019 16:47 #808378 by bluej58

Replied by bluej58 on topic Saving a 1980 750 twin.

Heavier cross hatching ?

78 KZ1000 A2A

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DoctoRot
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Oh, the usual... I bowl, I drive around...

30 Jul 2019 09:41 - 30 Jul 2019 16:11 #808429 by DoctoRot

Replied by DoctoRot on topic Saving a 1980 750 twin.

Some people smarter than I are thinking there may have been detonation. I found a video of the sound it was making. Thoughts? it was only coming from the right side and from the valve cover.

'78 1000 Long Term Project
'80 750G
750 Twin Big Bore Track Bike

Last edit: 30 Jul 2019 16:11 by DoctoRot.

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bluej58
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The chrome don't get you home

30 Jul 2019 14:19 - 30 Jul 2019 14:20 #808438 by bluej58

Replied by bluej58 on topic Saving a 1980 750 twin.

78 KZ1000 A2A

Last edit: 30 Jul 2019 14:20 by bluej58.

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DoctoRot
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Oh, the usual... I bowl, I drive around...

16 Nov 2019 23:44 - 16 Nov 2019 23:49 #814079 by DoctoRot

Replied by DoctoRot on topic Saving a 1980 750 twin.

getting a move on this. I decided to bite the bullet and get some custom JE pistons in 86mm bore. this will put the bike at 906cc. If you would like to get in on a limited run of pistons and sleeves let me know soon as I will be pulling the trigger on this in the near future.

Attachment IMG_0820.JPG not found

'78 1000 Long Term Project
'80 750G
750 Twin Big Bore Track Bike

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Last edit: 16 Nov 2019 23:49 by DoctoRot.

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DoctoRot
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Oh, the usual... I bowl, I drive around...

21 Feb 2020 22:51 #819671 by DoctoRot

Replied by DoctoRot on topic Saving a 1980 750 twin.

Think I found the source of the noise... unfortunately this went south so fast it damaged the crank as well

'78 1000 Long Term Project
'80 750G
750 Twin Big Bore Track Bike

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Nebr_Rex
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22 Feb 2020 04:10 #819678 by Nebr_Rex

Replied by Nebr_Rex on topic Saving a 1980 750 twin.

Go back to the post you made on Nov. 11 2018. Looks like the crank had issues from the start.

.

2002 ZRX1200R
81 GPz1100
79 KZ1000st daily ride
79 KZ1000mk2 prodject
78 KZ650sr
78 KZ650b
81 KZ750e
80 KZ750ltd
77 KZ400/440 cafe project
76 KZ400/440 Fuel Injected

www.dotheton.com/forum/index.php?topic=39120.0

.

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DoctoRot
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Oh, the usual... I bowl, I drive around...

22 Feb 2020 08:40 #819689 by DoctoRot

Replied by DoctoRot on topic Saving a 1980 750 twin.

You think that black stuff was a symptom? I checked the crank for all the things listed in the manual and sent it out to be professionally checked. what else can I do?

'78 1000 Long Term Project
'80 750G
750 Twin Big Bore Track Bike

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Nebr_Rex
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22 Feb 2020 18:33 - 22 Feb 2020 18:34 #819708 by Nebr_Rex

Replied by Nebr_Rex on topic Saving a 1980 750 twin.

Looks to me that one rod journal and the center main journal had been hot before assembly.

.

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Last edit: 22 Feb 2020 18:34 by Nebr_Rex.

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DoctoRot
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Oh, the usual... I bowl, I drive around...

23 Feb 2020 02:03 - 23 Feb 2020 02:04 #819720 by DoctoRot

Replied by DoctoRot on topic Saving a 1980 750 twin.

Hmmm that rod journal does look like it got hot. The main bearings all looked OK this time out. it was the opposite rod journal that got burnt up bad this time but both were shot. I’m thinking oil startvation. Gonna check out the oil pump closer. Any other suggestions for the next build?

'78 1000 Long Term Project
'80 750G
750 Twin Big Bore Track Bike

Last edit: 23 Feb 2020 02:04 by DoctoRot.

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Saving a 1980 750 twin.

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