Topic: CB750K Oil Pressure Problem

[acb]

If you remove exhaust caps 1 and 4, and run it for a short time on the centerstand, the action of the rockers will flick drops of oil out and you know the cam is getting oil, as those are the end of the line for the system.

And Ron means "exhaust tappet inspection caps". On the valve cover. Rockers are under there and you should get oil all over the front fender if yr top end is being properly lubricated with these removed and the engine running.

When we're talkin' "exhaust tappet inspection caps" we're talkin' about these, correct? (see photo)

So, to clarify, your light is now out and you have 10 psi with a warm engine at 1500 rpm? That sounds right. You haven't said whether you've revved past 1500 rpm to see if the pressure on the gauge rises. If you have access to compressed air, aim some into the back of your gauge- if it don't go above 10 psi- bad gauge. (I actually just tried this with keyboard duster stuff and got near 40 psi).

This is comforting info – thanks so much. Yes, I'm getting 10psi with a warm engine. I have reved up past 1500rpm with little change to the gauge reading – stays steady around 10psi at 3000rpm.  Also I know the gauge is working as sometimes when the start the bike it reads around 20psi then slow drops to 10psi as it gets warm.

Gonna start with what is probably obvious- O-ring on bolt, bolt into housing, spring on bolt followed by thrust washer then filter.

Gonna check the oil filter cap assembly as well as the exhaust caps now (once I confirm I'm looking at the right thing).

Thank you everyone for all the help!

[Brantley]

Those are the ones. 10psi at 3000 rpm is no bueno. If you didn't when you dropped in the new pump, replace the three o-rings that are around the locating pins.

[acb]

Solved!!!

After doing the exhaust caps test, which proved I wasn't getting oil properly to the top end (barely any oil was flicked out) and inspecting the oil filter assembly again I was feeling a bit hopeless.

I had been in touch with Mark "HondaMan" Paris a few months back about rebuilding my engine and decided to see if he knew anyone in the area (Denver) that could help me solve this oil issue.  He got back to me and suggested to take a look and see if anything was clogging the oil lines themselves.

I went to work to remove the lines and found the issue immediately - the previous owner replaced the stock lines with a homemade line (hose and hose clamps) and the "send" line from the tank was significantly kinked because it had to much length. The reason I hadn't noticed it until now was because it was difficult to see until I removed the tank and lines but then right away that seemed like the issue.

I cut the oil "send" hose a bit shorter and reinstalled to test – boom, the oil pressure gauge was reading 60-65psi!!!!  I'm currently on the hunt for some stock or aftermarket lines for a more permanent fix!!

So after all that the problem ended up being a kinked oil line! 

Thank you everyone for your help.  This was my first real post on the forum and all of the feedback and advice was invaluable!! I can't thank you all enough.

[MCRider]

Wow, that was unexpected! Glad you persisted and found it.

I have a pair of stockers. PM for price and S&H.

[mrrch]

Good to know, something to put into everyones memory banks.
You would have thought the oil would have started to overflow from the oil tank.

[lucky]

How many miles are on the engine??