my oil light keeps coming on on my '80 kz750 twin

It looked strange? How so?

Oil pump screen. Just throwing out a possible scenario & this may not be the problem --->>>. sometimes a goober will use too much sealant or the wrong stuff, which ends up in the oil, then blocks the screen. such as if a cylinder base gasket is replaced. It does happen, but again, just a possibility.

Screen access. I had guessed by removing the oil pan, but apparently, that is wrong. doh.

like it almost had gold shavings in it but it wasnt magnetic. So here is the thing, this is my first bike, my husband rides a harley and my father in law works on those. so this kawasaki is all new to them and to me. I just have always loved them so thats what i got. i just got it on friday.

So i am not sure what the sealant is your talking about. I dont know what anyone else has done to it. Besides that the only thing i know of is that the old owner had put stabilizer in the gas tank.

is there a way to check the sensor? or how do we drop the oil pan? should i just try and find that on youtube? I dont have a manual yet.

When exactly is the oil light coming on? My will come on if my idle is super low then go off when it gets above 1000rpms.

lilpeaty wrote: ok so on saturday when i changed it yhe guys at the shop i talked to told me to get synthetic 10w/40, the level was slightly high. so last night we drained the oild and replaced the filter agin wih regular 10w/40 since we thought that could have been the problem as well. my hsband took it around the block a couple time and she seemed fin but when i went to take her out the light came on again. Any thoughts? my neighbor thinks it could be a blockage of some sort due to the synthetic

Myth that syntetic causes blockage or leaks or anything else.

Does the light come on at idle or when it's running up?

Did you get the steel flat washer back on the filter to seal it?

lilpeaty wrote: the bike has about 41000 miles on it the old filter was actually pretty clean and so was the oil. i know the guy had it sitting for a few years but had kept some maintenance up on it. i am just worried about the motor seizing with how hot it gets. when we drianed out the synthetic it looked really strange but could be the stuff coming out of the motor?

That was my next guess. Sludge in a motor that sat too long will "free up" from the solvent and detergents in the new oil (any oil, dino or syn) and then that sludge could load up and block the filter or screen or whatever. Anytime you run oil and it comes out "looking strange", there must be crap in the engine.

I would drop the pan and see what's in there.

I would take off the side cover and check the oil pump and mesh filter. I've never touched a z750 before, but it's usually a pretty straight-forward job if you have a service manual.

Your oil grade should be fine, synthetic or mineral it shouldn't effect the pressure to that extent. Even non-JASO oil will be fine for oil pressure - but no good for your gearbox and clutch.

If it's sludge, it's so bad that it's blocking your oil pump - you'd want to strip it down anyway. If it's gunk caught in the mesh filter, you'll find it taking off the side cover - I know I did with mine, see below. And if it's the oil pump, you can take it off and check tolerances.

lilpeaty wrote: From reply #690577: like it almost had gold shavings in it but it wasnt magnetic.....

In case everyone missed the gold shavings comment. I don't know what that would be --- maybe from a bronze bushing that's gotten damaged or a clutch friction plate. ??? just wild guesses.

the oil filter looks fine so we are going to drop the oil pan and check the pump out. i am nervous about going further than that.
The oil that comes out does look like there are tiny shimmers of gold in it but we are not sure what that could be either. so is the general consensus that it is just because it sat for a long time and the new oil moved all the sludge around?
we will be working on it this weekend and hopefully she will be tip top so i can get in some more practice time before its too cold.

The light comes on when its idling and then the idle has to be higher and higher to keep it from coming on.

Don't drop the oil pan just yet --- the access may be different on the 750-Twin.
I would assume the oil pan should be removed, but I'm not familiar with the Big Twins. :blush:

Google "Biquetoast 750 twin"

Biquetoast used to be a member here and he has a lot of information on kz750twins.com

From a quick look at a pdf page from the 79 750 twin manual I think the oil pump access is via the oil pan

Take your finger and dip it in the old oil and go out in the bright
sun light and look at it if theres gold or silver specks in it and you are
having keep rising the idle rpm to keep the oil light off and you said it runs real hot
you have a rod, main or cam bearing issue.

Also if you open and rinse the oil filter with some carb cleaner in a clean pan you will see
if theres any metal in it.

lilpeaty wrote: The oil that comes out does look like there are tiny shimmers of gold in it but we are not sure what that could be either.

Back when I built engines that usually meant a bearing insert was being destroyed and shaving off metal.