1978 kz750 smoke

SWest
Offline
Sustaining Member
Registered
10 22 2014
Posts: 23379
Thanks: 2902

Re: 1978 kz750 smoke

26 May 2015 19:45

Thanks for the update.

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

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

Tyrell Corp
Offline
User
Registered
"You were made as well as we could make you"
Posts: 1650
Thanks: 261

Re: 1978 kz750 smoke

27 May 2015 07:02

#673974

oil ring broke in three pieces. One is in the crank case hopefully I can find it without splitting cases. Pistons look good cylinder walls look good.

I'm puzzled that an oil ring has broken and part of it escaped without damaging the cylinder wall... are the top compression ring gaps and piston / bore clearance within spec? No blue smoke or fouled plug, just white smoke and low compression from a broken oil scraper ring.

Is this a 750/4? Pics would be interesting...

1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces

The following user(s) said Thank You: missionkz

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

SWest
Offline
Sustaining Member
Registered
10 22 2014
Posts: 23379
Thanks: 2902

Re: 1978 kz750 smoke

27 May 2015 07:46

#673981

I made a suggestion on the 81 KZ 440 thread above this one. I suggest it be done in this case as well.
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

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

Soxx4u
Topic Author
Offline
User
Registered
Posts: 36
Thanks: 1

Re: 1978 kz750 smoke

27 May 2015 08:58

#673993

As I was pulling the cylinder off the piece of the oil ring fell down did not happen when it was running. I do not know bore spec. Everything looked tightas I was disassembling. Here are pics of what I have done

Attachment image.jpg not found

Attachments:

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

Soxx4u
Topic Author
Offline
User
Registered
Posts: 36
Thanks: 1

Re: 1978 kz750 smoke

27 May 2015 09:04

#673994

Attachment image-2.jpg not found

Attachments:

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

SWest
Offline
Sustaining Member
Registered
10 22 2014
Posts: 23379
Thanks: 2902

Re: 1978 kz750 smoke

27 May 2015 09:07

#673995

That looks like a secondary ring. Do the bore test and with new rings if within spec you should be good to go. A small piece in the pan shouldn't be a problem. The strainer and filter (if you have one) should keep it out of the oil galleys.
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

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

KZB2 650
Offline
User
Registered
Posts: 1475
Thanks: 265

Re: 1978 kz750 smoke

27 May 2015 11:31

#674022

Am wondering since you have it that far if you should pull the pan and look for that piece .... you could clean all the sludge and gasket material you probably dropped out at the same time..... and then you can wonder about doing something to the head.... I swear its never ending !! :laugh:

1978 KZ650 b-2
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket.

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

bountyhunter
Offline
User
Registered
Posts: 7245
Thanks: 338

Re: 1978 kz750 smoke

27 May 2015 12:40 - 27 May 2015 12:42

#674033

KZB2 650 wrote: Am wondering since you have it that far if you should pull the pan and look for that piece .... you could clean all the sludge and gasket material you probably dropped out at the same time.....

big +1 on cleaning the pan. You won't believe how much sludge will be in there. And you can "hose upwards" with brake cleaner spray and clean the underside of the internals while the pan is off.

You will want to get the valves turned and replace the seals while you are doing this, also the O rings on the oil feed pipes going up to the head. Guess how I learned that...... :ohmy:

1979 KZ-750 Twin

Last edit: 27 May 2015 12:42 by bountyhunter.

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

Soxx4u
Topic Author
Offline
User
Registered
Posts: 36
Thanks: 1

Re: 1978 kz750 smoke

27 May 2015 12:58

#674038

I have a full gasket kit. And valve guide seals. I don't plan on doing anything to the head. I'm broke to be honest. I picked this bike up to fix and flip.

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

SWest
Offline
Sustaining Member
Registered
10 22 2014
Posts: 23379
Thanks: 2902

Re: 1978 kz750 smoke

27 May 2015 14:12

#674042

Put the valve guide seals in and lap the valves at least.
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

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

Soxx4u
Topic Author
Offline
User
Registered
Posts: 36
Thanks: 1

Re: 1978 kz750 smoke

27 May 2015 14:46

#674055

How do I lap the valves?

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

Soxx4u
Topic Author
Offline
User
Registered
Posts: 36
Thanks: 1

Re: 1978 kz750 smoke

27 May 2015 14:48

#674056

I should be able to put the motor on its side to take the pan off and clean correct?

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