Top end rebuild - no oil

[Lrick1]

I just finished my first top end rebuild on a 08 xb12s, stock everything, new gaskets everywhere and followed the manual religiously.

The bike started right away, but sounded like crap... No oil in the system, duh! Shut it down right away, lasted 3-4 sec max. A bit of smoke and a smell of oil burning, which didnt worry too much (normal on first start after an engine rebuild right?)

Then pulled the fuel pump fuse, tried cranking to get the oil flowing but the battery keeps dying after 10-15sec (I need a new battery). Recharged. Retried a few times. The low oil pressure light wasnt going away.

im a bit scared to start it and running dry :-S

How long should I crank it for? should I just start and hope the oil pump lubricates the engine quick enough?

 

[Theycallmecrash]

Run it. You just did a top end correct? It takes a bit to circulate the oil

 

[Lrick1]

Yes, just top end.
How long can those engines run without oil? Id hate to have to take it all apart again...

 

[Theycallmecrash]

Every start up on a vehicle is pretty much a dry start. But i wouldn't rev until light goes off, no Longer than 30 seconds should pump up by then. Oil pressure can be audibly detected by the valve train noise rattling, ifnthe rattling subsides then you have pressure. If it keeps rattling you have a problem.

 

[user_deleted]

i'm not disagreeing with Jacob on his advice above as he knows these bikes very well....but another option you can try is remove the oil filter, fill it completely and this will assist in purging air from the oiling system, reinstall filter, remove both spark plugs(you do NOT have to rotate motor), check oil level, leave oil dipstick cap off....now crank away. dipstick cap off helps "burp" the oiling system. the light should go out in 15 seconds or less. just another option.

 

[Theycallmecrash]

^^^^ thats good advice less stress on the engine priming the oil system that way.

 

[UMDterp13]

Those 2 know their shit^^

+ Always prime an oil filter if it's going vertical to bottom of a motor, weather it's a lawn mower or a truck tractor!

I crank motor for a long time before it gets OP. About 30sec. It has to fill the cam area and oil cooler. I'd crank it for 30sec or so without spark plugs & fuel pump disconnected. Worst thing would be to keep spraying fuel in the motor and leak into the oil

 

[Lrick1]

Isn't the oil pressure light staying on as long as the engine isn't running?
I'm cranking with no plugs and no fuel pump, and I can't tell if I've got oil circulating. I uncoupled the pipes at the oil cooler to check right after cranking, and I do have a bit of oil dripping but not a lot. Can oil pumps get air locked in those engines?

 

[Lrick1]

Nevermind, the light did go out eventually, after about 1mn of non stop cranking

Now if the snow could melt, that'd be great...

 

[jetlee]

For future reference...

A quicker way to prime the oil pump is to loosen the cap on the bottom of the pump. This will let air out and let oil fill it up. Tighten it back up and fire the engine.