Topic: CB550 Oil Pressure Point.

[58webbing]

Having tested a few oil pressure switches to see what pressure opens the contacts and finding that even the ones marketed with a switch pressure of 0.6 - 0.8 bar (c 10 psi) are all switching at less than 5psi if they work at all! Not good enough! The genuine Honda switches are way too expensive considering their reliability. This has convinced me to fit an oil pressure gauge. I know this has been covered before but, what I cannot find is which oil gallery plug to use. There are two on the bottom right hand side of the engine, one between the points cover and clutch cover pointing downwards (vertical axis) and one directly under the points cover pointing outwards (horizontal axis)
Before I start to consider making up some fittings and planning a route for the pipe can anyone tell me what plug to use?

Thanking you in anticipation.

[Deltarider]

I have yet to hear of one case where oil pressure dropped on a SOHC Four dangerously low en route, although I can not rule out this happening to folks that thought it necessary to fit a gauge, sometimes in the weirdest (and most dangerous) locations... The choice is yours, but I decided long time ago that a pressure gauge without an electronic treshold alarm function is nonsensical. And I certainly would not create a possible problem by adding a gauge to a spot that Honda intended for diagnosis while servicing only. Also I dare say that practical all oil switches out there are better than Honda's that all seem to become dysfunctional sooner or later.

[bryanj]

The one below the points is the end of the main gallery feeding the crank so probably the best point.

[Bodi]

"diagnosis while servicing only"??
The gallery plugs are there to plug the galleries, nothing else.
Usually the right side cap facing right is used for an oil pressure gauge. You just drill and tap its centre (remove it first!) for a small plumbing fitting to attach the gauge or tube to, 1/8 NPT is standard here but metric threads can be used. Whatever is standard where you are. I carry a threaded plug in my tool kit in case the gauge or tubing breaks.
You can also tee off the switch hole for a tube to a visible gauge. I think that is metric although the NPT fitting will work.
I think you should keep the switch and light functional.
Yes they switch at around 5psi but that is normal for OEM and aftermarket oil pressure switches. Not enough for riding but adequate at hot engine idle.

[58webbing]

I now have the information I need thank you. I will be retaining the oil light. The oil gauge is to give me confidence as will a voltmeter so I know what is happening on a 45yr old bike with an unknown history. I would rather anticipate problems than be paying repair bills afterwards.

[Deltarider]

Bodi. I was told that checking the oil pressure was on the Honda mechanics to do list every 20.000 km or so. Nobody ever did it as far as I know. I also remember having it read somewhere but I can not reproduce it right now. No mechanic ever did it, btw.
The oil lamp is sufficient for warning. Your choice ofcourse but I'd rather have my eyes on the road at ALL times. What I personally find acceptable however is this:

Quote Pewe
    I have a charging indicator so I can have constant control
     http://www.ebay.co.uk/itm/LED-Motorcycle-Battery-Alternator-Charge-monitor-level-indicator-warning-bike-G-/200826330214

Although I don't need one myself, it's the best product presented in this forum. It's a direct fit, intuitive in it's use, can be tucked away between the speedo and the tach so it won't spoil the looks of your classic and above all by being in the line of sight, it won't compromise safety as other products and life endangering gadget-gauges do. And it's value for money too. Recommended. Wished they had a similar thing for oil temp: blue would mean engine is not yet warmed up, yellow = approching limit, red = overheating.

[Bodi]

Your eyes are not on the road if you're looking at the warning light.

[Deltarider]

Nobody does. Your attention gets drawn. That's different. Note that my proposed oil temp warning will show nothing (the blue led extinct) as soon as the engine is warm enough. Zero distraction. Man, sometimes I am in such traffic that I don't even dare to look at the speedo for a split second.

I carry a threaded plug in my tool kit in case the gauge or tubing breaks.

I wish you luck with that, if it's not too late...

[Bankerdanny]

The gauge on my 550 replaced the oil pressure sensor. I ended up switching back to the stock setup before I sold it last fall. I liked having the gauge, but it cluttered up the instrument panel and vibrations ultimately killed two gauges. If I had kept it I would have sprung for a good liquid filled gauge to protect it from future failure.

I may add one to my 750, but haven't decided.

[Deltarider]

Long ago I've considered to fit a gauge myself, but only with a programmable treshold sending an external alarm (visual or acoustical) like the ones I had seen in cargoships where everything is wired to warning lamps and acoustical alarms (they would sound at least every 45 minutes  ). Without a warning function, I consider such a pressure gauge nonsensical. What put me of even more is that the sender (on our CBs) would form an extremity and as a consequence be too vulnerable: the (oil path cap lower crankcase RH side). I would never forgive myself if it got damaged unnoticed, by manoevering the bike in the garage or by somebody else in a parking. So I balanced the risks and the outcome was: negative. What I add to my bike, has to be better in all aspects, not just one. I can do without 'improvements' that have side effects.