TOPIC:

I see you've reached 300 thank you's. This is Sparta!! I want be messing with this, lol

I've noticed the filter facing the rear as well. Mine facing the front on another bike looks like a rusty WW2 grenade after a while, good choice!

Just did another ride - a bit longer - 110 kilometers. Air temp. 78f/26c. Oil temp at sustained speed of 110/120 KPH - 68c. Oil PSI at 4000 rpm - 40lbs. 5000rpm - +50 lbs. Still 5 lbs PSI at idle. I'm happy !

scotch wrote: Just did another ride - a bit longer - 110 kilometers. Air temp. 78f/26c. Oil temp at sustained speed of 110/120 KPH - 68c. Oil PSI at 4000 rpm - 40lbs. 5000rpm - +50 lbs. Still 5 lbs PSI at idle. I'm happy !

Are you still using the oil pressure switch Scotch? I'm surprised it's not turning on the oil indicator light at 5 psi. At around 8-10 psi is usually where the oil indicator light should go out.
Your oil pressure numbers are a tad bit low suggesting to me that the oil pressure relief valve may be stuck open slightly or maybe your choice of oil and time for an oil change may be in order. Some oil stock use modifyers to thicken the oil when the temperature goes up and as the oil "wears out" meaning the modifyers are weakening the viscosity will not be there at higher temps.Other oil stock use modifyers to lower viscosity when the oil cools off and when these oils "wear out" the oil gets really thick when cold.
I like to see a minimum of 12-15 psi oil pressure at idle preferably 20 psi and 45-60 psi at operating rpms.on all stock engines and highly modified engines 25-30 psi at idle with a maximum of 60-70 psi at operating rpms. When I see numbers outside of "my numbers" I start to question what I see. Looking at the service manual it sugests the oil pressure should be 63 psi @ 5000 rpm which is the lower end of the operating range of the oil pressure relief. That oil pressure relief is a progressive relief meaning variable. They can tend to get stuck in a position especially when they spend a lot of time running at a constant rpm. Can't count how many relief valves I've pulled from vehicles and found them stuck open just above the opening point of the valve. They just seem to wear in to a happy spot.

KB - I'm still using the OEM oil PSI switch. I can't find a PSI Value in the manual. When I finished all the work on the bike - clutch, pan and screen service, etc., I filled the engine with Lucas 10-40 Semi-syn. I dumped it after two short rides < 120 kilometers ! It thinned out like solvent !!!! Went to the Lucas 20-50 and got some better oil psi readings as noted. Then installed the adapter. BUT - I had the same concern; To the point where I removed the filter adapter and manually opened the internal relief valve that's in the top of the oil-filter cavity. I used a "cleaned and dressed" pin punch. It was surprisingly "Light" ! I did this because of the "Lower" reading at idle and was wondering if I did in fact have some debris holding it open slightly. No visible evidence and I could hear a definitive "metal to metal" sound when released. So the question has arisen: Is the relief-valve spring "weak"? Note: When I start the bike "cold" The PSI gauge bounces a bit between 60/65 PSI. I take this a being the relief valve opening. Your comment doesn't "alarm" me but does give me reason to further question my low(er) reading.
I remember someone writing-in quite a while back about, ".....maybe not having an oil PSI gauge because it would stop your heart if you saw how low the pressure was at idle."
Anticipating the install of this filter adapter I installed my PSI and Temp gauge about a year and a half ago so I could establish some #'s and then do a comparison. Now having these #'s, the cooling effect is certainly apparent but you've raised this concern which now makes me wonder - Is the gauge that inaccurate? The irony should be obvious: Without a PSI gauge I would not know ! And playing the Devil's Advocate - How many actually have a PSI gauge and what are their readings?
Should point out as well: The Oil PSI gauge is a "Marshall Gauge 0-100 psi 1.5" Diameter Liquid 1/8" White Fuel Pressure Gauge" . Not a "scientific" quality by any stretch. I'm going to get the engine warmed-up and change-out this gauge for a 0-30 PSI (270 degree sweep) gauge and see what the idle reading is. I'll let you know. The prospect of having to remove the rad/headers and pan, again, is not exactly what I had in mind at this time but it may warrant a further check on the internal relief valve. The bright-side to having to do this is at least removing the filter won't be "messy" !

.....and so I begin "my Day"!!!! I need another coffee !

Supplement; just checked the OIL PSI at idle with the 0-30 gauge. #'s are close enough so now am feeling compelled to remove everything and get that relief valve checked-out , on the bench.

I just want to confirm that on a relatively more modern bike in comparison, a 2007 Vmax, the oil pressure reading are pretty much the same - around 60+ on cold start, and not more than 10 at warm idle. I have mine mounted on the handlebar. Depending on acceleration, it usually goes up to 40 when riding. I've been told that's a norm. Not a KZ1300, but a high powered engine of a similar displacement originated in the 80's, I think it's good to mention it for perspective.

One other thing I'd like to add scotch is you could go a step further and install and extra plate between your spin-on filter and the new spin-on adapter. There are cheap and simple ones with a port or two for attachments. Be it temperature or pressure sensor. So, you could have a second reading of the oil pressure right on the filter. Whatever you'd call it, but I see you are in the realm of academics at this point a bit already!
A step further, they can also come with ports for attaching hydraulic hoses for an external oil cooler. There are those oil coolers made like an elongated cylinder, some looking very attractive and shiny.
People mount them on the frame next to the water radiator, but you could have one in the back looking like a nice NOS bottle. It would fit your bike style, and I bet you would find a perfect place for it.

By the way, so many people swear by the Rotella T4 15-40. I am using it now on all the bikes, all with wet clutch. An old GL1100 Honda is just a work horse, I think it would run as well on olive oil, LOL. Vmax is much more picky and much closer to a KZ1300. My impression is it ran the best on Yamalube 20-50. Mind you, I don't ride in lower than -10 °C, and wait till the engine warms up before I go. It takes 15 minutes or so. I also cover a big part of the engine coolant radiator when riding or the engine would stay very very low in temperatures, too low for my comfort. And extra engine oil coolant wouldn't be a much desired addition in such riding conditions. I wouldn't use a 10-40 oil in general, I find 15-40 to be the lowest I go, and I might be switching back to 20-50, which I find a good fit for hot running bikes. I always wait till the engine warms up to operating temperatures after start anyway, I wouldn't want to stress the engine on too think or too think oil. Either way not good for lubrication, and in a way the oil pressure gauges become something of a less important gadget to monitor except for cold start and hard acceleration when a significant drop in pressure would indicate a failure (like the famous o-ring failure and fix on early Vmaxe's, which in a way just a different form is what a faulty relief pressure valve mentioned would do)

Further to the low oil pressure concern: Before tearing things apart to check the relief-valve I discovered I had a compound gauge that went to 12PSI. I warmed up the engine until my "marshal" gauge read 10 PSI at 800 RPM. Then installed the compound gauge. Started the engine and let the oil Temp. get to 80c. Here's the pressures/temp. of this test:

With the Marshal 0 -100 PSI gauge :
40c oil temp @ 3000RPM = 55-60- PSI. 12 PSI @ 800 RPM
12 PSI @ 800 RPM - 50c oil temp.
5 PSI @ 800RPM - 60c oil temp.

Switched to the 0 to 12 PSI 160 degree sweep compound gauge:
9.5 PSI @ 800 RPM 60c oil temp.
8.5 PSI @ 800 RPM 70c oil temp.
7.5 PSI @ 800 RPM 82c oil temp.

The small "Marshal" gauge is inaccurate at idle. I'm no longer concerned.

Stan: I spent countless hours looking for oil filter adapters that could be used and found nothing. Plus they were all bulky, required hoses and/or pipe nipples to mount the filter to some adaptation with brackets and would have forced me to have the filter up-front in plain view next to the headers. That was not an option for me.
I considered having some 1/8" ports milled into my spin-on adapter and decided against this for much the same reason. Unsightly and unacceptable lengths of hose(s) to route to where ever I would want a PSI gauge. Tee'ing off the OIL PSI switch for me, is a much better option. Knowing the gauge is not accurate in the 0 -10lb PSI range I can change the gauge for a higher quality one if I choose to. At least now I know that I am getting a usable pressure at idle. And considering I'd have been ignorant of the oil PSI readings without any gauge - I'm that much wiser and comfortable with what I have.
Thanks for the tech. input KB and Stan !