Oil Pressure Light

How concerned should I be that my Oil Pressure Warning Light is illuminating when I do hard launches? I don't remember it going on this much before I had the engine rebuilt (although it could have been burnt out or the switch may have not been working accurately). I know they cleaned everything up and checked the pressure switch, so I'm just curious how typical this is and if I should be concerned.

I'm running Castrol Motorcycle 20W-50 (bring up another question - why does the case say to run 10W-40?) and the level is good when I check it. No nasty leaks (just the stator cover) and no funny noises, although I'm beginning to become a bit paranoid.

I know this is common on the 900's, but I'm concerned about damaging the engine.

I run 5W40 Rotella and used to run 5W20 with no problems. 20W-50 is a bit heavy in my opinion. I believe that the heavier the oil the less it flushes because the slower it flows. Try to SLIGHTLY overfill the level and see if it still happens. If it do than your oil pump can be warn out.

Thanks!

Every shop I've talked to since owning the bike has said it "has" to be 20W-50.

I know they checked out the oil pump during the rebuild. I hate not doing things myself because I have no information on what they found, but they are a reputable shop around here and have been doing performance bike work since the 70's.

worry not.On hard launches, the oil rushes to the back of the oil pan and away from the oil pick-up which is in the front of the oil pan.Thus a temporary drop in oil pressure and the lite comes on..Schnitz Racing makes a simple little oil gate u can install which is basically a little flapper valve that closes when u accelerate and opens when u brake or slow down.I put one on my kz and it works as advertized.Unless ur really hammering on the bike frequently u probably dont need it but its available if u do.no problem to install either. .bj

manual calls for 20-40 by the way.bj

Actually the manual states. " SE class SAE 10W40, 10W50, 20W40, or 20W50" Realize that SE class had 1200PPM of ZDDP. Nowhere will mention that you have to run "Motorcycle Specific" oils. It states SAE="Society of Automotive Engineers" If you run Rotella-T motor oil of any viscosity you will meet and accede all oil specification requirements without breaking the bank for specialty oils. Modern automotive oils as of beginning of last year have very low quantity of ZDDP. This is because they are no longer designed for solid lifer cams, which we all run on these bikes.

So my next question would be, how do the lighter oil weights affect cooling with the higher compression 1075cc kit in it, as our engines are technically "oil cooled". And I ask because I know you have a larger piston kit installed too....

Lighter oils cool better because they flow faster. I do not believe in heavy oils.

You live in the same climate as me, so if it works for you - I'll give it a try and see what happens. Thanks!

Mine is a bored out 1089 cylinder to 1150. I do not have an oil cooler on the bike but will install one when i have a chance. They are not necessary but are a good idea. They do not hurt. On my Z1R that I pinched to 1105 I have a lot of heat problems when i get stuck in Chicago traffic. Those walls are very thin. They are about .030" thicker on my 1150.