Honda CB550K3 oil pressure

[Ashdowner]

My oil light came on today and wouldn't go off? What's the chances of this being a faulty pressure switch as opposed to a broken oil pump? I haven't yet done any checks like checking the wiring or running it with a tappet cover off to see if oil is getting there. The bike has done 29K and actually runs sweet as a nut above 4000 rpm, but of course that's a short burst cos I don't want to risk any damage. 

[matthewmosse]

I have probably done closer to 300k then 200k on cb500mand 550s and had a few oil lights come on, pretty well always pressure switch, personally I would swap that out as a first step, if possible for a gauge, but just as happily for a spare switch. I don't think I have ever had a dud pump, always worth checking the oil level and supply to the head, especially if any top end rattle, the oil galleries can block if any crud gets in.

[Bryanj]

Never seen a dud 500/550 pump, if it was a 500 maybe the primary chain worn through the oil gallery but 550 seems to have more clearance

[Ashdowner]

Thanks for that. I'll see if I can get hold of a pressure gauge and buy a new switch as a first step and keep my fingers crossed. Glad to hear the pumps don't fail. Couldn't be the oil strainer blocked could it? Yes my top end is a bit rattley but it's tappet noise, and no matter how many times I try to set the tappets the noise is there. Changed the oil 600 miles ago and the oil stays amazingly clean, but if there was any crud in the oilways how would you clear it without dismantling?

[Bryanj]

If you have just rebuilt it and left lots of bits af gasket and crud(technical term) inside yes the strainer could be blocked but there has to be a hell of a lot of crud in there to do that. Oilways can only be cleaned by dismanteling and as to tappets check that the exhausts are tight, I spent 2 hours redoing tappets to find a very slightly loose exhaust flange was causing the noise!

[hairygit]

You could try a flushing oil, BUT because some of the oilways are tiny, it may just move the problem around the engine. Try a gauge and new switch, if that doesn't sort the problem, then start thinking about stripping the engine to clean it. Also, did you change the filter when you did the oil change? False economy not to, nice clean oil running through a dirty filter

[mike the bike]

I would remove the rocker cover and crank the engine over on the starter with the kill switch off.  Check that oil is getting to the cam feed pipes.

[Bryanj]

No cam feed pipes on the 550, if you want to check for oil at the head remove the two end covers and then the brackets they fasten too, oil will come out of the holes if it is getting to the head, which is why there is supposed to be a soft alloy washer between the bracket and the cam cover to stop leaks

[matthewmosse]

When I had a hard to get rid of rattle in the top end of my cb550, it turned out after 3000 miles that the new O rings I had used in the rebuild were too thick, one had deformed enough to block an oilway and it dropped a valve, not to mention chewing the cam journal up a bit. Best to check.

[Ashdowner]

All good advice but I haven't rebuilt the engine and not sure if anyone else did before me. I'll check for oil at the head, get a new switch, and maybe I'll get pressure gauge to check it. Thanks everyone.

[Ashdowner]

I'm obviously getting oil pressure. The wiring wasn't great so I've redone it and the light now goes off immediately on startup. hopefully solved.