KZR's Bikes of the Month for 2024

Engine Oil Choices for a Z1

More
23 Jun 2024 13:34 #901192 by sdinse
Engine Oil Choices for a Z1 was created by sdinse
First a bit of background.  I just completed replacing the head gasket and most of the cover and oil pan gaskets to stop the leaks I've been having on my 73 Z1.  As long as the oil pan gasket was off, it was a good time to check the oil pump.  The screen was a bit clogged with what I would think is a bit of clutch material, not so unusual, so remove the oil pump, disassemble, clean, inspect and put back together.  Upon opening the pump, the gasket came apart in several pieces, some of which had to be scraped to remove, so consequently I needed a new gasket.  The gears and clearances seemed to be in good shape and within spec, at least for side clearance.  I did not measure the end clearance since I didn't have any Plastigage handy.  When the new standard sized gasket arrived, it seemed a bit thicker than the original, but then, the original had been compressed, so in went the new gasket and the oil pump was reinstalled.  This engine has never had a problem with low oil pressure but now I'm seeing the oil light come on at anything below 1500 rpm when hot.  Does anyone know what the switching pressure is for the oil pressure switch?

So, here's the question:  I filled the engine with Shell Advance AX5 20W-50 Motorcycle Oil( rb.gy/p1sgim ), could this be the problem?  It did seem a bit runny for a 20-50.  I'm thinking perhaps I should switch to a Kawasaki brand oil, but which one?  The K-Tech SAE 20W-50 4-Cycle Engine Oil( rb.gy/eej8ji ) touts "Protects against excessive viscosity decrease at high temperatures", which seems to be my exact problem at the moment.  Or would the KPO Conventional 4-Stroke Engine Oil( rb.gy/efv20u ) or the 4-Stroke Motorcycle Engine Oil 20W50( rb.gy/b4izgu ) be better or maybe even worse.  I'm thinking that any one of these should be an improvement but would like to hear of any knowledge or experiences to determine which would be the best choice.

This is my first step in diagnosing this problem, which is the easiest thing to do before tearing back into the engine.  Pressure testing cold is about 2 psi at 3000 rpm, a bit on the low side, but is it the oil or the pump?  Now I wish I'd never opened up my working oil pump.    A clear case of "If it ain't broke . . ."

  

Steve
1973 Z1 Since New

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

More
23 Jun 2024 15:06 #901200 by zed1015
Replied by zed1015 on topic Engine Oil Choices for a Z1

First a bit of background.  I just completed replacing the head gasket and most of the cover and oil pan gaskets to stop the leaks I've been having on my 73 Z1.  As long as the oil pan gasket was off, it was a good time to check the oil pump.  The screen was a bit clogged with what I would think is a bit of clutch material, not so unusual, so remove the oil pump, disassemble, clean, inspect and put back together.  Upon opening the pump, the gasket came apart in several pieces, some of which had to be scraped to remove, so consequently I needed a new gasket.  The gears and clearances seemed to be in good shape and within spec, at least for side clearance.  I did not measure the end clearance since I didn't have any Plastigage handy.  When the new standard sized gasket arrived, it seemed a bit thicker than the original, but then, the original had been compressed, so in went the new gasket and the oil pump was reinstalled.  This engine has never had a problem with low oil pressure but now I'm seeing the oil light come on at anything below 1500 rpm when hot.  Does anyone know what the switching pressure is for the oil pressure switch?

So, here's the question:  I filled the engine with Shell Advance AX5 20W-50 Motorcycle Oil( rb.gy/p1sgim ), could this be the problem?  It did seem a bit runny for a 20-50.  I'm thinking perhaps I should switch to a Kawasaki brand oil, but which one?  The K-Tech SAE 20W-50 4-Cycle Engine Oil( rb.gy/eej8ji ) touts "Protects against excessive viscosity decrease at high temperatures", which seems to be my exact problem at the moment.  Or would the KPO Conventional 4-Stroke Engine Oil( rb.gy/efv20u ) or the 4-Stroke Motorcycle Engine Oil 20W50( rb.gy/b4izgu ) be better or maybe even worse.  I'm thinking that any one of these should be an improvement but would like to hear of any knowledge or experiences to determine which would be the best choice.

This is my first step in diagnosing this problem, which is the easiest thing to do before tearing back into the engine.  Pressure testing cold is about 2 psi at 3000 rpm, a bit on the low side, but is it the oil or the pump?  Now I wish I'd never opened up my working oil pump.    A clear case of "If it ain't broke . . ."

  
Whatever oil you use do not use fully synthetic.
Only mineral or semi synthetic.
Depending on your climate 10/40 or 20/50 is all that is required.
These engines are high volume - low pressure so around 3 psi is normal but if you have increased side clearance in the oil pump due to a thicker gasket etc this will reduce the pressure.

AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
www.kzrider.com/23-for-sale/611992-air-c...lide-mikunis?start=0





The following user(s) said Thank You: sdinse

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

More
23 Jun 2024 17:24 #901206 by Mikaw
Replied by Mikaw on topic Engine Oil Choices for a Z1
I’m a big fan of good ol’ Rotella T4 Dino oil. 

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
The following user(s) said Thank You: SWest, sdinse

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

  • SWest
  • Offline
  • Sustaining Member
  • 10 22 2014
More
23 Jun 2024 18:44 - 23 Jun 2024 18:46 #901209 by SWest
Replied by SWest on topic Engine Oil Choices for a Z1
I use Rotilla also. I opened my pump in 2015 and sanded the side plate with 600 paper until all the marks were gone. There was a service bulletin about the gasket being too thick so I reused the old one. My oil pressure went up to 12lbs at idle and would break 20 at reves. One of our members pointed out some on eBay so I bought a few. 
 

here's another one. 
NOS Kawasaki #11009-1023. Oil Pump Gasket. KZ1000 A1. 11009-1023.
Im working up another pump and will install it soon. 
Steve
Last edit: 23 Jun 2024 18:46 by SWest.
The following user(s) said Thank You: sdinse

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

More
23 Jun 2024 21:54 #901212 by Cra-z1
Replied by Cra-z1 on topic Engine Oil Choices for a Z1
You have to watch those gaskets, most if not all I have seen and bought on ebay are way too thick. I ended up making my own using parchment paper which is about .0025 thick. You may need to cut and use two gaskets to get the proper clearance. I used the ones I purchased on ebay as the pattern and still have them for future pump rebuilds. 
The following user(s) said Thank You: sf4t7

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

  • slmjim+Z1BEBE
  • Offline
  • User
  • Enjoy Life! IT HAS AN EXPIRATION DATE!
More
24 Jun 2024 05:44 #901217 by slmjim+Z1BEBE
Replied by slmjim+Z1BEBE on topic Engine Oil Choices for a Z1
We have a NOS oil pump gasket that is literally paper thin.  Haven't measured it but, Cra-Z1's .0025 spec sounds about right.  Good idea about the parchment paper as gasket material.

RTV silicone might be worth a try.  Test before applying sealant by assembling bare & dry to make sure it spins freely.  Considering how flat the pump body and side cover are machined, a very thin wipe of RTV could be used on the cover plate, avoiding the gear area by a few mm.  Think thumb pressure wipe, leaving just a barely visible sheen of sealant.  And read the directions; apply RTV, assemble only finger tight, wait ~1 hr, or so, apply final torque.  Then give it a test spin.

Good Ridin'
slmjim & Z1BEBE

A biker looks at your engine and chrome.
A Rider looks at your odometer and tags.

1973 ('72 builds) Z1 x2
1974 Z1-A x2
1975 Z1-B x2
1993 CB 750 Nighthawk x2
2009 ST1300A

www.kawasaki-z-classik.com
An enthusiast's forum focused exclusively
on all things Z1, Z2 and KZ900.

The following user(s) said Thank You: Wookie58

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

More
24 Jun 2024 10:44 #901239 by sdinse
Replied by sdinse on topic Engine Oil Choices for a Z1
Parchment paper looks like the route I'll most likely use since you never know what you'll get when you place an order for a new gasket.  When I looked into gaskets according to the service bulletin, the only part number that I could find to order was for the standard thickness.  It seems that no one had ever heard of the thinner one, at least I could never find any listing of it online.

As far as going the RTV or 3Bond route, what is the torque spec for the oil pump cover plate?  Did I miss that in the manual?  I did notice that with a bit too much torque the gears would bind.  BTW, this is an early style pump that uses a gasket like this:

 

As for the oil, I think I'll try the K-Tech for its claimed "Protects against excessive viscosity decrease at high temperatures".  If this clears up the issue, then perhaps I can put off tearing into the engine until a future date.

Thanks everyone!

Steve
1973 Z1 Since New

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

More
24 Jun 2024 14:35 #901255 by Mikaw
Replied by Mikaw on topic Engine Oil Choices for a Z1
I think you can’t get much better than oil that can sustain a diesel over 500k miles. Good enough for me. 

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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

More
24 Jun 2024 18:15 #901269 by TexasKZ
Replied by TexasKZ on topic Engine Oil Choices for a Z1
The manufacturers buy their branded oil from a variety of suppliers. Among the best motorcycle specific oils are are Red Line and Mobil VTwin oil.

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

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

  • hardrockminer
  • Offline
  • Sustaining Member
More
24 Jun 2024 18:22 #901270 by hardrockminer
Replied by hardrockminer on topic Engine Oil Choices for a Z1
My father was an airforce mechanic in WW2.  His initial training consisted of filing a block of steel until the opposite sides were parallel to within 1/1,000 of an inch.  He also said the reason they did that was because the heads on Merlin Spitfire engines were hand fitted to the cylinder blocks without gaskets.  

The oil pump runs in the sump and I wonder if it can be run successfully without a gasket?  Leakage would simply go back to the sump.  The only issue might be too tight side clearance.

I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
The following user(s) said Thank You: Nessism

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

More
24 Jun 2024 18:37 #901273 by Nessism
Replied by Nessism on topic Engine Oil Choices for a Z1

My father was an airforce mechanic in WW2.  His initial training consisted of filing a block of steel until the opposite sides were parallel to within 1/1,000 of an inch.  He also said the reason they did that was because the heads on Merlin Spitfire engines were hand fitted to the cylinder blocks without gaskets.  

The oil pump runs in the sump and I wonder if it can be run successfully without a gasket?  Leakage would simply go back to the sump.  The only issue might be too tight side clearance.
Automotive oil pumps, the type internal to the engine, typically don't have any gaskets.  They use tight fitting parts, and as you say, if any small leaks occur, it's internal to the engine.   

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

More
24 Jun 2024 21:28 #901276 by sdinse
Replied by sdinse on topic Engine Oil Choices for a Z1

The oil pump runs in the sump and I wonder if it can be run successfully without a gasket?  Leakage would simply go back to the sump.  The only issue might be too tight side clearance.
If you look at the service bulletin 4/900-06, page 2, it states in one of the photos "GEARS SHOULD PROTRUDE SLIGHTLY ABOVE GASKET SURFACE", so it seems that KHI has engineered in the gasket.  I wish that weren't the case, it would make life much easier.  Oh well.

Steve
1973 Z1 Since New

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.