Well my wrist is finally out of a cast and have enough movement to ride the bike.

I stripped it down to fit new RO jets in hope it would sort out the mega overfuelling and to charge the battery where it hadn't moved for over 2 months.

When I took the carbs off there was some fuel in one of the inlet ports.

Got it back together and fired it up and took it round the block and the oil light came on, so turned it off immediately and pushed it home,

Just rebuild the entire engine and was not having any problems until now.

Could it be a failed sensor?

Perhaps.

Never run the engine with an oil light on.

A new sensor will be the easiest to try

If it's still doign it

Drain the oil and get the sump off.

You'd be amazed sometimes that crap can accumulate in the strainer and block it up, shaking it side-to side might be letting oil through.

Or one of the passageways could be blocked.

Hopefully it's a duff sensor, have you tried tapping the sensor?

Shaking it though will be moving oil around which might mean a blockage! :/

Cheers for the reply neo, any idea of the oil sensor part number had a look at the workshop diagrams but couldn't seem to find it.

Am I right in thinking its on the left hand side of the engine, fitted to the front head?

http://akhara.com/nc30/nc30parts/files/12.htm

Part number 2

Spoke to R.O and he suggested dropping the sump and checking the oil pick up filter, sure enough it was pretty clogged up. So cleaned it out and refitted it.

I tested the pressure sensor following the haynes method of removing the wire and turning the ign to 'on' there was no light so I assume its not the sensor.

The strange thing is when I prime the system by turning the engine over with the kill switch in the 'off' position the light will go out. Then if I fire it up the light will stay off for 20seconds or so then pop back up.

So Im guessing there is oil getting round when priming the system but not when running.

Really hope its nothing buried too deep internally.

Neosophist wrote: Drain the oil and get the sump off.

You'd be amazed sometimes that crap can accumulate in the strainer and block it up, shaking it side-to side might be letting oil through.

I did say that before ^^

You've a blockage somewhere. It sounds as though (and i'm just speculating here as i've not seen the engine) that perhaps when cranking it over, oil is being pumped up, which is creating pressure and turning the oil light off.. However, with the engine running, perhaps the sump is emptying (getting pumped upto the top) but not being able to come down fast enough (so it's running dry) and causing the oil light to come back on.

Dont' run it anymore, you risk doing damage (if not already done)

I had an engine once that some numpty had decided to use silicon sealer on instead of buying gaskets. Instead of doing a nice neat job they must have applied the silicon with a shovel, the sump was full of it and the engine was clogged to shit.

I ended up getting a Parafin gun on a compressor, removing the rockerbox cover, sump off, drain oil and blast through every passageway possible with 8 bar (120psi) of parafin airgun.

Engine was nice and shiney and clean and after replacing the knackered camshafts and shells it was once again fine.

You did indeed :)

I dont like the sound of that sounds like a complete strip down!! Only just got it all back together.

Is it worth changing the oil filter and putting in an engine flush to see it it helps clears the passageways. Does the oil filter have a bypass valve in if it gets clogged up?

Just trying to think of anything to do other than bit the bullet and take the engine apart as have nowhere inside, as much as I enjoy rolling around on wet tarmac prefer it when its dry.

Ive not used any silicone when reassembling it, use a mixture of grease and engine oil when putting the cams in.

Is the oil level measured with the dipstick screwed in or just rested on the threads, may just need a little more oil put in