Normal for oil pressure lamp going on on the kz900 ?

I notised that when riding and rpm is going up the red zone the oil pressure light comes on is this normal on the KZ900 ?

I'd say that a RED light at any time is not normal, and operating the engine in the RED rpm zone is also not normal...

My 2cents...

Not normal.
If you have the correct amount of oil in the sump and the pump screen is not partially blocked with debris they you should inspect the oil pump for wear and measure the side clearance which may need adjusting.
You should also check if the pump is an early one that was prone to cavitation and needs modifying by drilling a small 0.8mm hole in the body to correct it..
There is also a similar fix required for the early oil pressure switch which needs a 1.5mm drilling in the lift plate to cure a similar issue.


 

I might have a litte oil in the sump that is because after first oil-change that was done 200miles after rebuild i changed filter and filled 3,7 liter.
Then a few days ago (i have now done almost 1000 miles now) when checked oil it was covering the sightglass.I then sucked out 2,5 deciliter oil so i can see the oillevel . It is now at the top marking in sightglass .I usually dont ride up in the red sone but have done some test rides to se if the engine performs as i should.
It is mostly under hard aceleration the light comes on when rews go into red zone.
I had replaced the o-ring and the screen on the oilpump this winter.I tested it just by holding over the output hole and turned the sprocket and it gave
very good pressure so i did not open it to measure the propeller clearaces .Also if i had opened it i had to buy new gasket and did not have time for that. The old screen was clean no debris and sump was also clean.Im not sure if i have new or old type pump, but think i have new because of the look of the screen .I know the z1 had a screen that had 3 screws this pump has a press on screen.
Update just checked a vid i took vhen checking oil 2 days ago and the level is now between the markings on the sightglass so it is mayby to little oil when hard accelerate.I wrote that it was at the top mark but it is lower

Your pump is the later type and should have no cavitation issues..
Your oil level is fine but i personally like to keep it at the upper mark when cold.. ( leave the bike overnight for the oil to drain back down and cool before checking the level).
If the light is only coming on under very hard acceleration the cause may simply be due to oil surging to the back of the sump and away from the oil pick up .
This is a common occurance in that situation or drag racing etc and the fitment of an oil pan gate is the cure. 

Under hard acceleration the oil sloshes away from the oil pump screen.
There is a swing door mod/fix to prevent this oil starvation situation.

 
 
 

So that is what that swingdoor is for ! i saw steve posted a pick in a tread earlier. I have now cofirmed it is only when accel hard and the rews go up into red rpm zone the lamp turn on not if going slowly.Before i dicover that the lamp was going on i had drained 2,5 deciliter oil because the sightglass was full .I will put back 2 deciliter .I filled total 3,7 liter on last oil and filterchange.
 

Revs going into the red zone isn't a good thing, even with a swing door in the oil pan.  just my 2 cents.

When I warm start my Z1 (say after stopping for fuel), I'll occasionally get an oil light at idle.  It goes away once I increase RPMs.  I should note that I have an oil cooler with the feed and drain pointed down so the oil drains out when the engine is shut down.
I've replaced the pressure sensor, new wiring, and I have an oil pressure gauge.  Oil pressure reads normal when this happens as well.
I suppose it has something to do with the oil cooler.  I plan on re-routing the lines and re-orienting the cooler.
I'll pull off the pan as well and check the screen/pump.

 

Move0ver wrote:

When I warm start my Z1 (say after stopping for fuel), I'll occasionally get an oil light at idle.  It goes away once I increase RPMs.  I should note that I have an oil cooler with the feed and drain pointed down so the oil drains out when the engine is shut down.
I've replaced the pressure sensor, new wiring, and I have an oil pressure gauge.  Oil pressure reads normal when this happens as well.
I suppose it has something to do with the oil cooler.  I plan on re-routing the lines and re-orienting the cooler.
I'll pull off the pan as well and check the screen/pump.





 

Yes! it's most likely the oil cooler and if you flip the cooler so the feeds are at the top it will speed up circulation and also retain a little extra oil in the cooler.
Also if the pipes have a long run to the cooler you should fit a thermostat so that the cams etc get an instant feed from cold.
Without a stat it can take a few seconds for oil to fill the pipes and cooler especially on the first firing of the day which gives the cams etc an under lubricated start and will lead to premature wear of the cams and shells.

I think it is safe rewing into  the red rpm zone but not if you  standing still. The engine is manufactured to tolerate that. I almost never rev the engine this far and i did it to check that it performs well.

MoveOver : maybe youu could switch to a oilcooler like this that have a thermostat www.rpmracingca.com/proddetail.asp?prod=M%2FC%3AFJCoolerKit
 

Rolf1976_KZ900 wrote:

I think it is safe rewing into  the red rpm zone but not if you  standing still. The engine is manufactured to tolerate that. I almost never rev the engine this far and i did it to check that it performs well.

 

Cranks are good for spinning close to 11k rpm at which point the roller bearings start to skid and break the oil film but it's pretty pointless if it stops making power before that.
I set the rev limiter at 10.5 k on the drag bike but it would pull beyond that if it wasn't for the limits of the bearings.
The  8k - ish redline is due to them running out of steam much above that on the stock tune but the crank is still running well below its limit.