No oil pressure after rebuild?

[ibanezlynx]

Hello everyone,
Finished building the m900 today after top end engine rebuild/bike restoration over 1.5 years.
Turned it over by hand many times. Then hit the starter with the plugs out and earthed. Spun it multiple times for 5-10 seconds in bursts. The oil pressure light won't go out.
Went to the Haynes and it recommends disconnecting the oil pressure wire, turning on the ignition and earthing it against the crankcase. Did this and the light comes on.

Not sure what's going on. Has the pump lost prime? What would the gurus recommend is my next step?
Thanks,
Si

[Darren69]

I'm not sure what the Haynes test would prove? That the earth to the oil pressure sensor was good or not? More likley the switch itself has failed. In which case the test would prove nothing. Its quite common for the pressure switch to fail. Have you got oil on the rear cam? The oil pump is mechanical so it should pump if its turning. Pull one of the rear cam covers and look.

[Stuart42]

Had similar on mine.
From what I remember, if when you turn engine over the oil level in the sight glass goes up rather than down, you have missed replacing , or it has not seated correctly, an o ring under the right hand engine case.
Cheers Stuart

[ibanezlynx]

Hi Stuart,
Thanks for the heads up, however the right hand engine case hasn't been off during the rebuild so I can rule that one out.
Going to try what Darren69 says tonight and pull a cam cover off and see if oil gets to the heads indicating pressure.
Cheers.

[Darren69]

It might just need a bit of priming. Even under normal starting I read somewhere that it can take a couple of minutes for oil to get up there.

[Darren69]

I'm informed that this Vauxhall part is the same and cheaper:-

http://www.ebay.co.uk/itm/191007122438?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[Dukedesmo]

The Vauxhall sender is the same, I wanted a new one for the Monster so bought a couple because they were so cheap. A few weeks back my Son's Corsa had the oil light on and started blowing oil out of the sender so I used my spare on that.

Turn it over on the starter (not running though) with the oil filler cap, pressure gauge or oil cooler feed pipe off, you'll soon know if it's pumping... :eek:



Tip: stand back... http://i57.photobucket.com/albums/g212/nickterry/bukkake.gif

[Darren69]

I was gonna suggest pressing the palm of a hand over the hole or find a volunteer! :)

[ibanezlynx]

NOW FIXED!!
So this is what I did:
I removed the pressure switch and the right oil cooler hose at the cooler end. I then cranked the engine and nothing so obviously no flow... I filled a large syringe and tube with oil and forced quite a lot of oil down the hose back towards the engine. Replaced the pressure switch. I then continued to crank the engine with the end of the hose in a container. After a few cranks a little oil came, a bit more then full flow of oil. Replaced the hose and cranked the engine and now the oil pressure light goes out... result.
Motorapido sent me the wrong plugs so now I have to wait to start the engine haha...

[ibanezlynx]

Ps thanks for all the suggestions...

[Dookbob]

The priming with the syringe trick is worth remembering for a motor that has been standing idle for some time.

[utopia]

I had to do a similar priming job with a syringe when I fitted a replacement engine in my Dommie.
Unfortunately, I didn't make adequate checks beforehand and therefore the engine ran for a minute or so before I realised the problem.
I crossed my fingers and assumed/hoped that I'd got away with it.
That was 5yrs ago or more, and (luckily) no problems have arisen.