TOPIC:

car5car wrote: It is very easy to check. Check oil level when engine is running. I think it should be seen in the glass. Maybe below "low" line but you have to see it.
Another question is checking oil level procedure. Different bikes have different procedures in owner's manual Some of them say to check cold engine, some say to start engine, stop it and wait 5 min.

On the KZ engines it is checked COLD.

Agree. You cannot measure the oil level when the engine is running. All you will see is oil flowing across the site glass. Ed

When I finish hooking up my cooler I will check the oil level, fire it up, shut it down and adjust the level. It's not complicated.
Steve

Has anybody ever measured how much oil a cooler and lines holds?

My old one held close to a quart but that was just guessing. The way the lines were and the height of the cooler made the oil run back down quickly. Hopefully I will have solved that problem. What does the book say about oil capacity vs a bike with no cooler?
Steve

According to the FSM supplement for the KZ/Z1100B, an extra 0.2l should be added for the cooler. That is about 6.8 ounces.

A little less than 1/2 quart. That won't hurt anything.
Steve

In all my 30+ years of riding and racing various zeds to which we have fitted oil coolers we have never had one damaged or blow due to oil starvation because of the cooler and have never over filled an engine or added any to compensate for a cooler.
Just fit the cooler. Keep the oil towards the upper level when cold and job done - EASY.
Nothing complicated or mysterious about that contrary to what some people are trying to imply and the non existent mountain of zed motors wrecked due to the fitment of oil coolers is proof.
My own tuned Z1R has an oil cooler (with bottom feeds) . It's my only main transport all year round and has been permanently on the road for the past 20 years and hundreds of thousands of miles.
It gets the correct 3.7ltr of oil when I service it and if there was an oil capacity problem due to the cooler it would have gone bang years ago.
Which it hasn't.

I'm with Nessism on this one. The oil level in the sump while the engine is running is what must be maintained. Find out how much oil the cooler system holds and add that to the amount needed to reach the full line on the window. If that higher level when the engine is cold and the cooler is empty causes problems, be careful to not rev the engine during a cold start. Monitoring that higher oil level poses a problem, but I think that could be solved. A dip stick would be easy to mark at the higher level.

A dip stick isn't possible on the early big fours. We're only talking about 1/2 quart here.
Steve

80B4 wrote: I'm with Nessism on this one. The oil level in the sump while the engine is running is what must be maintained. Find out how much oil the cooler system holds and add that to the amount needed to reach the full line on the window. If that higher level when the engine is cold and the cooler is empty causes problems, be careful to not rev the engine during a cold start. Monitoring that higher oil level poses a problem, but I think that could be solved. A dip stick would be easy to mark at the higher level.

Trying to solve a problem that doesn't exist.
Even with a cooler fitted and cold oil level on the high mark the oil will barely clear the sight glass when running which is still a hell of a lot higher than the pump pickup and under normal conditions the engine will run happily with the oil level at the lower mark when cold ( that's why there is a lower mark ).
There is more than enough oil in the sump even when the level is on the low mark .
If there was a problem with oil starvation when fitting a cooler to these engines it would have been found much earlier than 40 years after they were first produced by a bunch of random forum members with too much time on their hands.

Nothing is impossible if you own a CNC machine.
I will have to raise the oil level window the next time I machine a clutch cover. I may even design one that accommodates a dip stick