78 kz1000ltd weird back pressure in oil system?

Scirocco wrote: Just for testing the oil flow i would made direct loop oil line and see if your back pressure happens again.

I was going to suggest the same thing.

Also, you could see if the local auto parts store (AutoZone, etc) will loan you an oil pressure tester like this. They often will loan tools for free.

www.harborfreight.com/Engine-Oil-Pressure-Test-Kit-62621.html

It can be connected in place of the galley plug on the right side to confirm that you have pressure after the cooler return line.

seanbarney41 wrote: Just had another thought...
My filter bolt seems too long. Could it be bottoming before the cover gets full tight?

Maybe try a good fitting washer or "gently" try turning the cover as to not un seat the o ring just before it gets tight. Don't go too tight cause I've read of others cracking it by over tightening.

And is there a spring and some kind of vale inside this bolt ? Could this do something like this guys ? I've looked at mine before and really didn't know how it works or how to check that it is.

I saw the spring with the filter. Do you still have the washer? The washer will stick to the filter and thrown away with the filter.

The spring can be used without the washer. I'd put it together, take off the inspection port fitting , fire it up and see if oil comes gushing out. It should take only a few seconds. If not shut it down and find out why.
Steve

I had the washer up until the last disassembly. It is somewhere in my drain pan. All the washer does us protect the filter grommet from the spring.

Lots of things to try here, so thanks. I will update if I find something.

So still not sure why it could be blowing the o ring out. Could this be caused by lack of crankcase breathing

my old brain is fuzzy, but this is my bet

So still not sure why it could be blowing the o ring out. Could this be caused by lack of crankcase breathing

Never ever will a gas medium (blowby pressure in a engine case) compress a liquid like oil.
Open your oil filler opening and you will not feel any over pressure.

ned37 wrote:

So still not sure why it could be blowing the o ring out. Could this be caused by lack of crankcase breathing

my old brain is fuzzy, but this is my bet

ned, I overhauled the crankcase last night and found nothing but the stone axe simple parts Kawasaki put in there...It's all wide open. What could go wrong with it? ...plus what Scirocco said makes perfect sense

I have read this thread intently for the last several days and a lot of good 411 has been posted. Just thinking about the initial problem of having an o-ring blow out doesn't make a great deal of sense to me in this situation, but what really complicates the situation is the fact the filter cover is or becomes loose after the so-called blow out. Anyone can correct me if they wish because I am not familiar with this engine, but when you torque down the filter cover it compresses the o-ring and continues to do so until the cover meets the pan. In essence there should be no gap between the parts for the o-ring to escape. I am not an engineer, but I would think you would have to be talking about some seriously high oil pressure to get the filter cover o-ring to blow out of its position. Can this oil pump deliver that type of oil pressure? What is the normal oil pressure for this engine? In my brain if there was a high oil pressure problem I would be more apt to believe you would see oil escaping from other areas, or perhaps escaping from between the block and the filter cover, but not literally blowing out the o-ring seal. If it were my bike I would go back to square one and put the bike back together and install an OEM o-ring on the filter cover and properly torque it downn with a known good torque wrench. I would also install a temporary oil pressure gauge and fire up the engine while watching the gauge taking note of any excessively high readings. Something just doesn't seem right to me with the fact the o-ring is blowing out and I would check the filter cover for any cracks or deformations along with the o-ring grove and make sure the cover is flat. I would have to assume that the oil level is correct or should be and not overfilled. Last but not least I would take a close look at the area where the filter cover meets the block to ensure all is well there. As a wise old mechanic once told me, look for the easy stuff first.

Rick H.

Are you using an oem kaw filter oring? Could simply be too big and not seating like it should

So, I have double and triple checked air flow through all accessible passages...all good. Close look at bolt screwed in to block all the way til it bottoms with no other parts, measure from oil pan surface to flange head surface of bolt, 20mm give or take, hard spot to get super accurate. Thickness of oil filter cover is exactly 20mm. Is this how things should be?

Check to see if the cover is flat with a straight edge.
Steve